Newbee: 1978 CB550K - Wrist Twisters
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post #1 of 43 Old 07-29-2010, 11:08 AM Thread Starter
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Newbee: 1978 CB550K

Hello and thank you for reading my post. Bought the 78 CB550k complete but sitting for many years. I thought the transmission was seized but I just worked it loose so now it's going through the gears. I still can't turn the engine over. I now have the engine on my work bench because I thought I was going to take it apart, but now with the gears working loose, I'm thinking it's not seized but just sitting too long and the pistons need to break free from the cylindars. My questions are, am I on the right track?? If the piston sleeves are rusted will I have to have them replaced?? Someone told me they were steel and could be replaced?? Is there any type of cleaner that I could put into the cylindars that would help break free the pistons??

Thank you again
Michael

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post #2 of 43 Old 07-29-2010, 11:45 AM
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post #3 of 43 Old 07-29-2010, 12:10 PM
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You got to post some pics, brother! I'm looking forward to following your adventure.

的 said I never had much use for one.
Never said I didn't know how to use it."
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post #4 of 43 Old 07-29-2010, 12:22 PM
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post #5 of 43 Old 07-29-2010, 12:38 PM
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Quote:
Originally Posted by mlito View Post
Hello and thank you for reading my post. Bought the 78 CB550k complete but sitting for many years. I thought the transmission was seized but I just worked it loose so now it's going through the gears. I still can't turn the engine over. I now have the engine on my work bench because I thought I was going to take it apart, but now with the gears working loose, I'm thinking it's not seized but just sitting too long and the pistons need to break free from the cylindars. My questions are, am I on the right track?? If the piston sleeves are rusted will I have to have them replaced?? Someone told me they were steel and could be replaced?? Is there any type of cleaner that I could put into the cylindars that would help break free the pistons??

Thank you again
Michael
The CB550 has cast iron cylinders. Remove the spark plugs then squirt a rust buster into the combustion chamber as recommended. You might get lucky but you have only scratched the surface. A motor that will not spin freely is a motor with major neglect. Any and all rubber parts from the cam chain tensioner to the valve guide seals and everything in between are more than likely dry, brittle, or broken. The carburetors are also a disaster x 4.

There are a few old farts here that are familiar with the SOHC Honda fours. Another excellent site is the Single Over-Head Cam 4 Forums

What are your intentions? Simply get it running and hope for the best? What is you mechanical background with motorcycles? Not trying to scare you just giving you my $0.02. BTW: I'm one of those old farts...lol-

Welcome aboard

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post #6 of 43 Old 07-29-2010, 12:59 PM
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I'm an old fart. too. Dad had a '72 CB500, I had a 75 CB750F. I did a top end job on that 750.

的 said I never had much use for one.
Never said I didn't know how to use it."
Mathew Quigley
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post #7 of 43 Old 07-29-2010, 01:17 PM
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Quote:
Originally Posted by Bigdaa View Post
I'm an old fart. too. Dad had a '72 CB500, I had a 75 CB750F. I did a top end job on that 750.
My 750 err 812 would eat Z1's for lunch.

* 750cc bored out 3mm to 812cc.
* 11:1 compression ratio.
* R.C. Engineering aluminum alloy golden rods.
* Andrews D grind cam.
* 29mm Mikuni smoothbore carburetors w/K&N individual filters.
* Dyna III electronic ignition.
* High energy Andrews coils.
* Ported and polished combustion chambers.
* Balanced pistons with custom designed crowns.
* Heavy-duty valve springs.
* Reinforced cam towers.
* Precision ground 4130 heat-treated alloy cylinder studs.
* Custom fabricated 0.5mm aluminum head gasket.
* Plus countless hours of grinding and polishing with the trusty old Dremel.


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post #8 of 43 Old 07-29-2010, 01:29 PM
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That's an impressive bike, fellow old fhart.

的 said I never had much use for one.
Never said I didn't know how to use it."
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post #9 of 43 Old 07-29-2010, 06:20 PM
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Fill the cylinders with diesel, let sit for 3 days, and rotate back and forth alittle till it turns freely.

It has worked on MANY Tractors and car engines which is cast iron cylinders.

Just another idea!

Good luck and pics when finished!

I Can and will ride anything!
Bikes I own:
New addition 1978 CB750Four
2006 919
1994 home built springer
1984 KLR 600
1953 Servi-car (I gotta get this put back together)
1942 WLA (Gotta finish this one as well)
1985 Honda 200M ATC
1985 Honda ATC 70
1997 Yamaha Big Bear 350 4X4 ATV
Early 1984 Ironhead Sporty (Wife has laid claim to this bike)
1986 Sporty that I am putting a ironhead engine into
YEA BIGDAA I Gotta GUN!
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post #10 of 43 Old 07-30-2010, 06:24 AM Thread Starter
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Thank you all for the input. Bought some PB Blaster Penetrating Catalyst last night and didn't have any luck but if I may I have a quick story. This was a bike I bought in hopes of taking the engine and putting it on an Odessy go kart for my two boys. It was going to be their project but the Odessy frame needs work and of course when the engine didn't turn over they became disscouraged and lost interest. I on the other hand kept asking around and the more I asked the more I felt the engine wasn't seized. Lesson one, never give up!! My boys are coming over from time to time watching what I'm doing and I tell them to keep the glass half full and never give up.
To offer more info. on me, Machinist, cabinetmaker, very hands on but never opened an engine. This is a project for me, and if/when this engine starts, then I'll return to the bike to see what I can do to restore it. Money is an issue, one kid in college, one in private school. My two biggest investments and worth every dollar. My obervation to being an old fart which I'm slowly becoming is that Old farts seem to lose the most important thing they had, "the fire in the belly" My goal is to never lose the "fire in the belly" and never give up. I hope I haven't bored anyone with my gibberish.
I'm going to put the engine back on the frame, connect the chain so that I can get some torque to turn over the engine. I'll rock back and forth and move slowly. More to come.

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post #11 of 43 Old 07-31-2010, 08:37 PM
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Quote:
Originally Posted by mlito View Post
Thank you all for the input. Bought some PB Blaster Penetrating Catalyst last night and didn't have any luck but if I may I have a quick story. This was a bike I bought in hopes of taking the engine and putting it on an Odessy go kart for my two boys. It was going to be their project but the Odessy frame needs work and of course when the engine didn't turn over they became disscouraged and lost interest. I on the other hand kept asking around and the more I asked the more I felt the engine wasn't seized. Lesson one, never give up!! My boys are coming over from time to time watching what I'm doing and I tell them to keep the glass half full and never give up.
To offer more info. on me, Machinist, cabinetmaker, very hands on but never opened an engine. This is a project for me, and if/when this engine starts, then I'll return to the bike to see what I can do to restore it. Money is an issue, one kid in college, one in private school. My two biggest investments and worth every dollar. My obervation to being an old fart which I'm slowly becoming is that Old farts seem to lose the most important thing they had, "the fire in the belly" My goal is to never lose the "fire in the belly" and never give up. I hope I haven't bored anyone with my gibberish.
I'm going to put the engine back on the frame, connect the chain so that I can get some torque to turn over the engine. I'll rock back and forth and move slowly. More to come.
Be careful.
Even if you get the bottom end free and turning, should you have a valve seized open, you'll jam a piston into the valve head.
I'd be inclined to fill the cylinders with a good rust penetrant (diesel can be quite effective, that prior suggestion being a good and valid one) and letting it sit for a few days.
The remove the dyno cover that on the left side.
Inside you will see a decently large sized bolt that hold on the charging system rotor.
Use a 18 or 24 inch flex handle with a long socket ( or short socket with 3 inch extension) and just try to break it free - don't do a major or full rotation.
Just break it free, then get the head off and see what you are dealing with cylinder wise.
SOHC Hondas are easy to work on.
The above mentioned website has the official factory manual for no charge downloading. There is also an excellent carb manual as well.

My 73 CB750 is still sleeping in the garage in long term storage state, had it since new, although I have not licensed it for 15 years.

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post #12 of 43 Old 08-01-2010, 08:05 AM
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Quote:
Originally Posted by mcromo44 View Post
Be careful.
Even if you get the bottom end free and turning, should you have a valve seized open, you'll jam a piston into the valve head.
I'd be inclined to fill the cylinders with a good rust penetrant (diesel can be quite effective, that prior suggestion being a good and valid one) and letting it sit for a few days.
The remove the dyno cover that on the left side.
Inside you will see a decently large sized bolt that hold on the charging system rotor.
Use a 18 or 24 inch flex handle with a long socket ( or short socket with 3 inch extension) and just try to break it free - don't do a major or full rotation.
Just break it free, then get the head off and see what you are dealing with cylinder wise.
SOHC Hondas are easy to work on.
The above mentioned website has the official factory manual for no charge downloading. There is also an excellent carb manual as well.

My 73 CB750 is still sleeping in the garage in long term storage state, had it since new, although I have not licensed it for 15 years.
If you bought a 73 CB750 new, you must be an old fart.

Spoiler:

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post #13 of 43 Old 08-01-2010, 11:55 AM
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Originally Posted by rickard919 View Post
If you bought a 73 CB750 new, you must be an old fart.
Ahh, rickard919, you know it to be true !!!!

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post #14 of 43 Old 08-02-2010, 06:21 AM Thread Starter
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Thank you mcromo44

I was starting to remove the top end but had bad luck when it came time to removing the gear and chain that connects the cam to the crank. The 4 inch gear, as you all know, has two bolts that need to be removed. Because the engine can't turn over, I only have access to one of the two bolts. I can't get the top head off because of that. Any suggestions?? I'll try diesel and see what happens.

Thanks again

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post #15 of 43 Old 08-02-2010, 07:49 AM
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Quote:
Originally Posted by mlito View Post
I was starting to remove the top end but had bad luck when it came time to removing the gear and chain that connects the cam to the crank. The 4 inch gear, as you all know, has two bolts that need to be removed. Because the engine can't turn over, I only have access to one of the two bolts. I can't get the top head off because of that. Any suggestions?? I'll try diesel and see what happens.

Thanks again
Try removing the cam chain tensioner. Maybe the amount of slack it will provide will allow you to get at the second cam gear bolt. The above also tells me you have it out of the frame, otherwise the valve cover can't be removed (although I have a hazy recollection of the 750 automatic frame allowing in frame valve cover removal). Anyway, in frame is the easiest way to hold the engine if one is to try the above crank end bolt method although the engine can be wedged instead re resisting the flex handle torque on the bolt. An upside down engine position would be my suggestion.

Good luck with it.

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post #16 of 43 Old 08-02-2010, 07:55 AM
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It's too early in the morning. I screwed up. While my comments about the cam chain tensioner and crank end bolt method still stand, my comments about in frame work re valve cover removal may be off base. You have a 550. My experience was all 750. I have no clue as to whether in frame valve cover removal is possible. You have the valve cover off, so, would you be open to saying whether you were able to do that in frame or out of frame ?

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post #17 of 43 Old 08-02-2010, 09:15 AM Thread Starter
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thank you mcromo44

Yes the motor is out of the frame and I have removed the tension bar. No extra play or not enough to get at that second bolt. Thanks for throwing out suggestions, it really helps to know that either I'm on the right track or not.

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post #18 of 43 Old 08-02-2010, 09:52 AM
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Quote:
Originally Posted by mlito View Post
Yes the motor is out of the frame and I have removed the tension bar. No extra play or not enough to get at that second bolt. Thanks for throwing out suggestions, it really helps to know that either I'm on the right track or not.
Do you have access to a torch ?
If so, try to eye ball whether a custom bent wrench could get at the lower bolt.
If it looks good, go buy a cheap wrench, heat to red, and shape it.
Failing that, cut the chain.
But, let a few days pass and first see how the cylinder soaking does for you.
Cutting the cam chain is a last choice move in my mind, but remains a valid solution.

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post #19 of 43 Old 08-02-2010, 10:18 AM Thread Starter
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Thanks again

I think I can re-shape a wrench, 10mm I believe?. If I understand the proceedure, I loosen the gear, remove the chain, then slide out the cam shaft. I have a question, how do put the cam and gear back so that you're close to it's original position?? One other question, someone said that with the engine sitting for so long, all the internal rubber will be dry rotted and need to be replaced. What am I looking at as far as cost. This is saying that the heads can be cleaned and pistons, rings, valves are not bent or burnt, just replacing all the seals and guides OR, having the top open, would it be best to just do a complete overhaul?? I would commit to doing this for the experience and learning but money will be an issue for me. Thanks again.

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post #20 of 43 Old 08-02-2010, 10:24 AM
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I don't think anyone asked yet so I will point this out: Get a shop manual for your bike asap. This will be worth it's weight in gold.

And get us some pictures if you can. By the way, none of this is gibberish. It's like manna from Heaven for more than a few of us.

的 said I never had much use for one.
Never said I didn't know how to use it."
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post #21 of 43 Old 08-02-2010, 11:53 AM Thread Starter
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manual for bike

Thank you and yes I have the manual on a pdf file on my computer. I totally understand the comment of the interest in this project so I will try to explain with as much detail as is possible. I'm not looking at the rest of the bike yet until I can tell if the motor will run, and how much it will cost to get it running. The bike came complete but it was sitting for many years, I don't know how many. The engine and surrounding areas of the engine are very clean for sitting for so many years. No oil spilling out, a very externally dry looking engine. So far I have worked the transmission free I can get it into netural, second (down one) and third (down two), that's all. When I try to kick start the engine that's on the bench, I put it into netural and press on the kick start, there is very little movement, maybe one degree at most. I want to say with my novice knowledge that it feels like it's hitting something solid when I bring the throw back to the beginning of it's swing and start over again. I was going to put the engine back into the frame hook up the chain to the sproket and the rear wheel and put it into gear in hopes of moving the engine but something is telling me to hold off right now. I'll try to get some pictures up asap. Thank you again

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post #22 of 43 Old 08-02-2010, 02:55 PM
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Quote:
Originally Posted by mlito View Post
I think I can re-shape a wrench, 10mm I believe?. If I understand the proceedure, I loosen the gear, remove the chain, then slide out the cam shaft. I have a question, how do put the cam and gear back so that you're close to it's original position?? One other question, someone said that with the engine sitting for so long, all the internal rubber will be dry rotted and need to be replaced. What am I looking at as far as cost. This is saying that the heads can be cleaned and pistons, rings, valves are not bent or burnt, just replacing all the seals and guides OR, having the top open, would it be best to just do a complete overhaul?? I would commit to doing this for the experience and learning but money will be an issue for me. Thanks again.
10 mm going by memory from a long time ago.

Here are the steps.
Remove the chain adjuster assembly from rear of cylinders.
Back off all the rocker adjusters.
Remove the rocker shafts.
Get the 2 cam gear bolts out.
Move the gear across and off its resting area on the cam.
Drop the chain off the gear.
Weave the cam out through the gear slots.
Be ready to move the gear and cam to align for easier passage.
Retiming the cam is easy.
Set the crank at the T mark on the ignition breaker plate re cylinders 1 & 4.
550 details at the top are not known to me, but should be same or very similar to the 750 design the 550 is very similar to.
Look for a three marks on the end of the cam, two should be on the horizon with the third vertical and positioned at the top.
(this looking at the rocker arm box from the side of the engine and at the end of the camshaft)
It's easy work.
Oh yes, if the 550 is like the 750, when you are removing the head, DON'T miss first removing the 4 small bolts that hide below the 4 rubber plugs beneath the rocker boxes !

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post #23 of 43 Old 08-02-2010, 08:12 PM
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p=========i==========c========ssssssssssss

的 said I never had much use for one.
Never said I didn't know how to use it."
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post #24 of 43 Old 08-04-2010, 05:16 PM Thread Starter
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Here are some engine pics.

I was able to get a few photos of the engine I'm working on. So here they are. I haven't be able to free the engine. I mean I still can't get it to turn over. I still feel like something is hitting so. "I'm going in" and will try again to get the top jugs off. This time making a special wrench to get that second bolt off of the cam chain sproket.
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post #25 of 43 Old 08-04-2010, 06:47 PM
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Quote:
Originally Posted by mlito View Post
I was able to get a few photos of the engine I'm working on. So here they are. I haven't be able to free the engine. I mean I still can't get it to turn over. I still feel like something is hitting so. "I'm going in" and will try again to get the top jugs off. This time making a special wrench to get that second bolt off of the cam chain sproket.

I see you have the clutch cover off.
Might as well release the clutch and then know you have separated the transmission from the engine.
Be careful removing the bolts, back out half a turn at a time for the first few turns then go to one turn at a time.

I see you have the valve cover off.
Remove the cam tower bearing caps and inspect.
If they look OK, then fine.
Where I'm coming from is this. I did a repair on a 750 back in the 70s. An upper oiling passageway got blocked and one cam tower ran dry and welded the cam to the tower. In that case, the cam broke, and the engine ran on two cylinders - i.e. on the engine half that still had an operating cam. I see it as remote possibility that you have a seized cam from that experience, very rare, noting your cam is still in one piece, but still a possibility so why not check.

If you separate the transmission from the equation by releasing the clutch hub stack, and the top end is not seized, can't get it free after a cylinder soak and a flex handle on the alternator retaining bolt, then remove the head and have a look.
If the cylinders look good, then something bizarre is going on. I'd say that if the engine is cylinder seized, there should be obvious rust signs above the pistons on the walls.
The carbs don't look that bad in the picture. If the cylinders were rusted up I'd have expected the carbs to look worse. Maybe the picture is deceiving.

I'm more than just casually interested in how you make out, and good luck as you go deeper.

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post #26 of 43 Old 08-04-2010, 06:58 PM
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The CB 500/550 is a totally different head design from the CB750.

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post #27 of 43 Old 08-04-2010, 07:16 PM Thread Starter
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Thank you mcromo44

I'll try to post more pictures in a few days. Yes I've tried to soak the cylindars, remove the clutch plates, and have tried to rotate the engine in several different ways. So yes The next thing to do is to remove the upper head. I will also take a look at the tower bearing caps when I get into that part of the engine. I just returned from a trip to Sears where I purchased a 10mm open-end/box wrench. I'm taking it to work tomorrow where I have the use of a torch and will customize the tool so that I can reach that second bolt on the cam gear. I'll keep my camera close to show all what I find. Thanks again for your input. I'm finding myself getting charged about this project. Questions please, how much would it cost for a complete gasket set for the rebuild project?? Are there generic gas tanks to purchase?? The one that came with the bike is in externally good condition but it sounds like a pound of sand in the tank when I hold it and shake it. I don't have keys for the tank or the ingnition so I also have to figure that our as well. Thanks again. Michael

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post #28 of 43 Old 08-05-2010, 07:49 AM
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Quote:
Originally Posted by MisterMike View Post
The CB 500/550 is a totally different head design from the CB750.
Mister Mike,

I've never been inside one so don't know.
Haven't looked for a manual to browse either.
Off the top, what's the basic difference?
Are the cam towers integral with the head casting?
1 minute max, no fishing about at your end intended.


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post #29 of 43 Old 08-05-2010, 08:27 AM
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Quote:
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One other question, someone said that with the engine sitting for so long, all the internal rubber will be dry rotted and need to be replaced. What am I looking at as far as cost. This is saying that the heads can be cleaned and pistons, rings, valves are not bent or burnt, just replacing all the seals and guides OR, having the top open, would it be best to just do a complete overhaul?? I would commit to doing this for the experience and learning but money will be an issue for me. Thanks again.
When I bought my cb650, it was in really, really rough shape. She would leak a quart of oil onto my left knee every 60mi. I found a complete gasket kit from Vesrah I think it was, for about $60, and the carbs were easy to rebuild on mine (only had to replace the float bowl o-ring) because I had PD and not CV carbs. That being said, my parts guy said there were many more parts available for the CV carbs. (ie. Diaphragms, jets, float bowl needles, etc..)

Do not loose faith! I've got over 300,000kms on that cb650 now, and other than replacing all the gaskets, about 20 heli-coils(previous owner not backing off valves and torquing the valve cover -hence the leaking), I lapped the valves, changed the clutch twice, replaced the pulse generator (as the engine heated up, I would loose 2 cyls) and have been through a few sprockets and chains. All with original internals. My old bike simply will not die.

Being that our bikes are similar, I would figure gasket availability and parts would be easy enough to find.. They're great bikes that receive lots of compliments and attention wherever you go.

Good Luck!

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post #30 of 43 Old 08-05-2010, 12:23 PM Thread Starter
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300,000kms !!!!!! There is hope after all. Thanks for the company name for the gaskets. I went to there website and it was a little odd trying to navigate but I'm sure I'll find what I'm looking for as soon as I find out what I need. I'm going to remove the top end to see what it looks like. I'll take pictures for all to see. How can I tell if I have CV or PD carbs??
Thank you

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post #31 of 43 Old 08-05-2010, 12:37 PM Thread Starter
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Photo of my modified 10mm wrench

Just want to show you the wrench I prepared to get at that second bolt off the cam gear on the top end.
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post #32 of 43 Old 08-05-2010, 01:08 PM
lusting over something...
 
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... I just typed a nice explanation, then my cat clicked on the back button w/ his face and I just lost my nice explanation.

basically, CV use a rubber diaphragm to lift the mains, and PD use a mechanical linkage. CV -correct me if I'm wrong folks, had a smoother actuation and ride, whereas the PD or slide carbs offered instantaneous, acceleration at the downside of you feeling every little 'jerk' of the throttle.

CV usually have a big raised cylinder, and my PD were long, short and narrow.

Now, in my case, I wanted to switch to the CV because of the lack of availability of jets for my specific carbs, but discovered that even though the CB650 came with both CV and PD carbs, the spacing on the head for the intake was entirely different forcing me to either abandon (which I did) or create a new brace and linkages which would allow for proper spacing or to find a head that was designed for CV carbs.

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post #33 of 43 Old 08-05-2010, 01:24 PM
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Quote:
Originally Posted by mlito View Post
300,000kms !!!!!! There is hope after all. Thanks for the company name for the gaskets. I went to there website and it was a little odd trying to navigate but I'm sure I'll find what I'm looking for as soon as I find out what I need. I'm going to remove the top end to see what it looks like. I'll take pictures for all to see. How can I tell if I have CV or PD carbs??
Thank you
Those are not CV carbs.
What you have a so called PD carbs (which once you have downloaded the carb manual from the SOHC site, you will start referring to a slide throttle valve carbs - direct linkage actuated type that is)

Given the age of the bike, be thankful they are not CV type, is my feeling on the matter.

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post #34 of 43 Old 08-05-2010, 01:27 PM
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Quote:
Originally Posted by mlito View Post
Just want to show you the wrench I prepared to get at that second bolt off the cam gear on the top end.
excellent and hopefully it does the trick !

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post #35 of 43 Old 08-05-2010, 07:18 PM Thread Starter
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Got it OFF, WOW what a Job

Ok, with my 10 mm wrench I bent and reshaped today, I was able to break loose the second bolt on the cam gear. I took me a long time to move that bolt out of the way to allow the cam to raise and exit through the cam gear. OK, I still can't get the cam chain tensioner out but for now that's ok. So I removed the top head to expose the cylindars. Not a pretty sight, please see all the pics I've included for you all to comment. Out of the four cylindars, it appears the two in the center are at TDC and the two outter are at BDC. Am I right? I also get the impression that for engine smoothness the two inner and two outter are at 180 degrees apposed to each other, right?? In the outter left, picture inclosed there is alot of rust, the outter right it's not that bad, In the two center they are at TDC, so am I to believe that the cylindar walls might be in good condition below the pistons?? I tried to remove the cylindar head but it just did not move and I was running out of daylight. So I've stopped for today to add these comments to you all. Any feedback would be really helpful. Does it look like the engine is just frozen because of the rust?? Could it be something else?? Thank you very much, I had fun tonight taking this little bugger apart.
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post #36 of 43 Old 08-05-2010, 07:31 PM
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I have had a ton of old SOHC Honda motors apart. What I'm looking at is one of the worse cases of neglect ever. If it was mine it would be going straight to the dumpster. I know its not what yo want to hear but so be it, my $0.02. 2 up 2 down, for the pistons. Play with it but be prepared to spend a shit load of $$ to get it running.

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post #37 of 43 Old 08-05-2010, 09:06 PM
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Quote:
Originally Posted by MisterMike View Post
My 750 err 812 would eat Z1's for lunch.

* 750cc bored out 3mm to 812cc.
* 11:1 compression ratio.
* R.C. Engineering aluminum alloy golden rods.
* Andrews D grind cam.
* 29mm Mikuni smoothbore carburetors w/K&N individual filters.
* Dyna III electronic ignition.
* High energy Andrews coils.
* Ported and polished combustion chambers.
* Balanced pistons with custom designed crowns.
* Heavy-duty valve springs.
* Reinforced cam towers.
* Precision ground 4130 heat-treated alloy cylinder studs.
* Custom fabricated 0.5mm aluminum head gasket.
* Plus countless hours of grinding and polishing with the trusty old Dremel.


Real nice build.
Whose pistons went in ?
I'm surprised at the aluminum head gasket, did you ever try the Action 4s copper gasket - although it was dimensioned for an 836 kit.
Any Jerry Branch ideas in the porting by chance ?

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post #38 of 43 Old 08-05-2010, 09:18 PM
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Uh oh ..............
I see little chance of ever again getting ring seal without a bore job and therefore piston kit.
It looks so bad that I'd be concerned about pounding out babbit on the big ends trying to smack the pistons free.
2x2 with a mallet on the piston top.
Even then it won't be easy, the crank is not going to naturally want to turn as the throws are straight up and down.
The valves and guides will be useless.
The cam looks rough.
$$$$$$ for sure.
Back to the pistons. They have that fused look to them, as in to the bores.
Try a whack on each piston.
Try the flex handle on the alternator end.
If no move, change battle plans.
Flip it over, split the cases, remove the rod big end caps, then try to remove the barrel assembly with the pistons and rods in it, and go from there.
Who knows, maybe the bottom end and tranny won't look that bad.
In practical terms, the most you can really hope for, short of cubic $, is a decent set of cases with tranny and bottom end OK.

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post #39 of 43 Old 08-05-2010, 09:22 PM
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Quote:
Originally Posted by mcromo44 View Post
Real nice build.
Whose pistons went in ?
I'm surprised at the aluminum head gasket, did you ever try the Action 4s copper gasket - although it was dimensioned for an 836 kit.
Any Jerry Branch ideas in the porting by chance ?
Thanks...
Pistons began life as stock Honda 64 mm blanks, don't remember the exact bike they were for. The crowns were shaped and measured over and over to achieve a 11.5:1 compression ratio. Valve pockets cut, radical slipperized the skirts, polished crowns, then all 4 were balanced to within 0.5 grams.

The 0.5mm head gasket was hand made. one could be used over and over with Yamabond. Never had a failure. The porting was to exactly match the combustion chamber to the 64 mm cylinders. Micro polishing and smoothing of rough edges meant more HP.


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post #40 of 43 Old 08-06-2010, 06:13 AM Thread Starter
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Well I tried

Thanks for the honest truth about this engine. I don't have the extra $'s to start throwing around on a project that could end up being very expensive. What's true is that I would like to work on a motor project but this might be too much only in terms of $'s. All of you have been very helpful, and I appreciate it very much. The knowledge use guys have is worth a tremendous amount of respect. So how do I get rid of a bike that is totally torn apart but is pretty useless?? Thanks again Michael

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