[nd4spdbh]

Just note again the gauge will be very sensitive, oil just slightly less dense than water, and water is like more than 1/10th less dense than mercury. Just oil is more viscous than water so it won't jump around like water. But it works out and its MUCH cheaper than a mercury gauge.

 

[Islandboy]

Just did this, with a proper gauge. When first checked after firing bike up all were off. 5 min of adjustment and I got all dialed in equal. Idle is noticeably smoother. Low speed crawl is great. I also replaced the vacum hoses since there were signs of 15yrs use. Small cracks at the ends.

 

[mcromo44]

Just did this, with a proper gauge. When first checked after firing bike up all were off. 5 min of adjustment and I got all dialed in equal. Idle is noticeably smoother. Low speed crawl is great. I also replaced the vacum hoses since there were signs of 15yrs use. Small cracks at the ends.

What make of gauge set is that?

Great point on aged out vacuum lines, if there is something that can be counted on to wreak havoc on engines, it's leaking vacuum lines!

 

[Islandboy]

The gauge is an English brand. Carbtune pro. There is no fluid. It's dry. Has small weights which get pulled up. Also inline dampners to reduce pulse. Very easy to use. Quite accurate and quick to respond. By the time the engine was hot enough for the fan to cut in I had it dialed in.
All valves compared to No.2 were off. No.3 by over a dozen clicks. I'd move the nuts by a couple of clicks and wait a bit for the gauge to settle. Repeat.
Yeah the old vacum hoses while I don't think they were leaking they were very stiff/hard and had small cracks where pushed over the joiner. They had to go. The new hose felt nice.

 

[Superdog]

I need to look into one of those. I have a Motion Pro with blue fluid, and while it works, it can be a real PITA. Always getting bubbles in the tubes.

Sent from my XT1575 using Tapatalk

 

[mcromo44]

The gauge is an English brand. Carbtune pro. There is no fluid. It's dry. Has small weights which get pulled up. Also inline dampners to reduce pulse. Very easy to use. Quite accurate and quick to respond. By the time the engine was hot enough for the fan to cut in I had it dialed in.
All valves compared to No.2 were off. No.3 by over a dozen clicks. I'd move the nuts by a couple of clicks and wait a bit for the gauge to settle. Repeat.
Yeah the old vacum hoses while I don't think they were leaking they were very stiff/hard and had small cracks where pushed over the joiner. They had to go. The new hose felt nice.

Thanks for the info re Carbtune.
I just had a fast look at their web site and I see they also have some other slik trik carb' specific tools.

 

[gammer]

I have one of those CarbTune tools, except I think mine is a II model. I've used it many of times to sync in-line 4 carbs. Very easy to use.

Thanks for the write up and posts from everyone, this will be helpful when I sync my 919 up, as it does have the idle burble that others are describing. Upon looking, it looks like the PO blocked off the pair system on my bike. I might give this a go this weekend.

Quick question:
Does it make sense to drive the bike for a bit to get it up to operation temp? Or is it too hot to work on when its already warmed up?

 

[Islandboy]

I only just warmed my bike up. Just so it idled well. When the vacum hoses are disconnected the bike will run like poo until it enters closed loop. May need a little throttle input. So you may want to warm bike up a bit.
But not too hot because. Uncomfortable when working on the vacum hoses especially No.3. Also these bikes do heat up quick when not moving. I used a big fan blowing on radiator but bike still heated up quickly enough that the bikes own radiator fan came on. I had the valves synced by then, about 5 min. I also deliberately left of until a cool time of year. Start of winter here.

 

[gammer]

Got mine sync'd up today. Luckily #3 was already sync'd. I was having trouble getting the the socket on #3 when pre testing. I just needed to adjust #1 and #4. #1 was off by the most.
I also had to remove the left side coil to have enough room to get at the #3 hose and the 5 way joiner.
This is one of those maintenance jobs you do for peace of mind to know its running right.

 

[Islandboy]

Yeah I agree, it's a maintenance for peace of mind job. My bike was running fine but idle and low speed is noticeably smoother. No more random stutter. I can now with no clutch or throttle input walk the bike along just on idle, 1200rpm, smooth. No lurching etc. I didn't know my starter valves were off, actually none were the same as No.2. I'm glad I did it.

 

[samuelc]

Got my Carbtune pro today and I can't wait to try it. I am having a lot of lurch when I am going slow. I have a homemade tube type manometer that I use but it is so sensitive it will suck the atf through it real fast if its off a lot. I think this is off a lot. This will get me in the ball park then I can with to the super sensitive one if I feel lt necessary. I love listening to a smooooooth engine.

 

[Islandboy]

Good luck and let's us know how it goes.

 

[samuelc]

here is some photos. I know they are turned but you get the picture. lol I followed the directions except I connected the tubes to the throttle bodies and did not disconnect or remove lines at the 5 way splitter. Could not see the point.this tool is very nice to use and I checked it against my homemade manometer and it was spot on. Then one line came loose at throttle body and it sucked all the aft into the lines. Now it must sit for hours to drain back and equalize. Well I won't ever need it again. This carbtune is great. My bike is smoother than it was. No more herky jerky at low rpm. Sweet and crisp throttle. Well worth the time doing it and money for the Carbtune.

 

[Islandboy]

Great result and the Carbtune is a great tool for the job.
The starter valve synchronization definitely smoothed out my bike at no and small throttle positions. Combined with a pc111usb and a great map I have zero lurching at low speed now. I can even just let the clutch out with no throttle and the bike will roll away and crawl on just idle, no lurching.

 

[gammer]

I can even just let the clutch out with no throttle and the bike will roll away and crawl on just idle, no lurching.

+1 to this.
After I did my sync, I was maneuvering in slow traffic and realized the bike was putting along with the clutch out and no throttle applied.

 

[Thomas Shannon]

hey guys, new to the 919. although i did have the 919cbr some years back

when i sync the starter valve its very smooth without the map hoses being plugged in, once i plug the map back in it slightly lumpy again. i checked the voltage return and its with in spec for my altitude. no split hoses either. its annoying. i do not have this pc3 software. iv checked valve clearances today, one was slightly tight and one was loose, so lucky for me one was 195 and one was 190. so got them back in spec with out having to go out.

Any ideas on why my map sensor is making it run jumpy ?

 

[Islandboy]

Try a new sensor.
What sort of air cleaner are you using?
Make sure your airbox is sealed off. So no leaks. Like the drain tube, crankcase breather tube, the flapper tube etc.
There is a procedure for cleaning the starter valves in the workshop manual.

 

[Thomas Shannon]

hi, yea i pulled them off the bike and cleaned the starter valves also checked for any leakage at the air box seals/throttle body rubbers ect. it runs just perfect with the map disconnected, with it connected it idles +-100 and just sounds rough.. the sensors are fairly expensive. i dont know if one of you guys are out near Westhill Aberdeenshire so i could borrow it just to confirm, the test voltage was 2.75 so its in spec. also im using an oem equivalent from hiflow

 

[Islandboy]

Well your airbox is good, starter valves clean. So definitely rule out the map sensor before looking at other stuff.
What about a second hand one? Wrecker or eBay.

 

[Thomas Shannon]

once you connect the map back the idle drops 100 rpm or so. while adjusting the starter valves, adjusting the idle throws they sync a little. this is probably the reason. the bikes only done 14k. runs real nice while the bodies are independent to the vac gauge. its strange how all the bodies are connected to each other effectively before the starter valves so the vacuum of another cylinder will effect the rest of the cylinder systems.