carbon buildup? - Wrist Twisters
 
Thread Tools Display Modes
post #1 of 13 Old 10-03-2010, 08:59 PM Thread Starter
Cornicen
 
Join Date: Nov 2009
Location: Manila, Philippines
Posts: 516
Blog Entries: 1
Rep Power: 1
 
carbon buildup?

Something I hear a lot from bikers here is "bouncing it off the redline every so often is good to remove the 'carbon build-up', A softly run bike doesn't run as well as one that sees the redline regularly"

After a high-revving hard session, the bike does seem to run better the next day. (Almost like when you clear your throat?)

...any truth to this? And if so where exactly does the "carbon" build up?

honda ng gingsa is offline  
Sponsored Links
Advertisement
 
post #2 of 13 Old 10-03-2010, 09:06 PM
McTavish
 
mcromo44's Avatar
 
Join Date: Oct 2007
Location: Calgary
Posts: 5,596
Rep Power: 1
 
Quote:
Originally Posted by honda ng gingsa View Post
Something I hear a lot from bikers here is "bouncing it off the redline every so often is good to remove the 'carbon build-up', A softly run bike doesn't run as well as one that sees the redline regularly"

After a high-revving hard session, the bike does seem to run better the next day. (Almost like when you clear your throat?)

...any truth to this? And if so where exactly does the "carbon" build up?
Actually, what really cleans nicely is a bit of water injection under full load.

Typically, if water is not used, and an engine runs better after a hard run, it is for one reason and one reason only. The spark plugs have been cleaned off by the high gas velocities and turbulence from full load power. RPMs alone do nothing, the engine has to see load. If you have lots of carbon and oil deposits on the piston/combustion chamber/valve head surfaces, a hard run can hurt the engine by causing edges of the deposits to glow red and pre-ignite the cylinder. This is called Pre-Ignition, which is very different from Detonation, commonly known as "Knock".

mcromo44 is offline  
post #3 of 13 Old 10-03-2010, 10:20 PM
Le So Cal Troll
 
nd4spdbh's Avatar
 
Join Date: Sep 2009
Location: So Cal
Posts: 5,766
Rep Power: 1
 
redline a day keeps the carbon away

i believe it to keep some carbon deposits off.... tho i have never been nice to any of my stuff so i have nothing to really compare it too.

I personally think it plays in part with cleaning the fuel injectors... ur at max rpms at a good heavy load assuming WOT... thus your duty cycle on the injectors is going to be nearly 100% or full open, and fuel pressure is going to be up there as well to feed those injectors, then all the sudden you shut them down completely (rev limiter) and thus pressure builds up behind them, then BAM you re open the injectors with a high pressure burst of gas going through em.

Every time my moms 99 chevy started to run rough, id take it for a 3 mi drive, getting it to redline in 1st WOT once or twice.... always cleared the sticky injectors right up (a common problem with that year that was later fixed.)

nd4spdbh is offline  
post #4 of 13 Old 10-03-2010, 10:32 PM Thread Starter
Cornicen
 
Join Date: Nov 2009
Location: Manila, Philippines
Posts: 516
Blog Entries: 1
Rep Power: 1
 
Ok, maybe not in the "clearing the carbon" sense (whatever and wherever that carbon is) but there seems to be some truth to it then.

honda ng gingsa is offline  
post #5 of 13 Old 10-04-2010, 02:37 AM
Pob
Tirone
 
Join Date: Apr 2010
Location: UK
Posts: 53
Rep Power: 1
 
Modern 4-stroke engines with modern fuels do not get excessive amounts of carbon on things anyway. I would not worry about it. Engines stripped after 100,000 miles show only small amounts of carbon. 2 -strokes on the other hand are a different story but modern synthetic 2-stroke oils and more effecient engines have reduced it a lot. You find carbon on the top of the piston, valves, cylinder head and exhaust ports but as I said with a 4cyl 4-stroke I wouldn't worry, most bikes will never see more than 50,000 miles in 20 years.

Pob is offline  
post #6 of 13 Old 10-04-2010, 05:36 AM
Pilus Posterior
 
3dcycle's Avatar
 
Join Date: Apr 2007
Location: St Johnsbury
Posts: 2,026
Rep Power: 1
 

Awards Showcase
Donation Outstanding Restoration Outstanding Restoration Outstanding Restoration 
Total Awards: 5

Quote:
Originally Posted by Pob View Post
Modern 4-stroke engines with modern fuels do not get excessive amounts of carbon on things anyway. I would not worry about it. Engines stripped after 100,000 miles show only small amounts of carbon. 2 -strokes on the other hand are a different story but modern synthetic 2-stroke oils and more effecient engines have reduced it a lot. You find carbon on the top of the piston, valves, cylinder head and exhaust ports but as I said with a 4cyl 4-stroke I wouldn't worry, most bikes will never see more than 50,000 miles in 20 years.
this is all fine exept for the fact that modern gas (with ethonal) sucks it starts to separate within a week.so if you run a tank through everyweek you are fine, but if not it causes problems, i have seen on smaller engines where after sitting a while i crapping gas would gum up the intake valve so much that when cranked over it would open and not beable to close. granted this was not a motorcycle but a ATV but i have seen it at least 3 times.

3dcycle is offline  
post #7 of 13 Old 10-04-2010, 07:27 AM
Cat Herder
 
FlyCatcher's Avatar
 
Join Date: Sep 2007
Location: Winchestertonfieldville
Posts: 1,788
Rep Power: 1
 
Garage

Awards Showcase
Veteran Veteran 
Total Awards: 2

My dad always said that when I was a kid. "Burn the carbon out". Thought he was just making up excuses to run the hell out of things. I know I always like to "burn the carbon out" once in while

Never noticed any difference in the way it runs. Guess I burn it out too much

2015 Ducati Monster 1200S

"Anyone who says money can't buy you happiness has obviously never used money to buy a Ducati motorcycle."
FlyCatcher is offline  
post #8 of 13 Old 10-04-2010, 10:51 AM
McTavish
 
mcromo44's Avatar
 
Join Date: Oct 2007
Location: Calgary
Posts: 5,596
Rep Power: 1
 
Quote:
Originally Posted by 3dcycle View Post
this is all fine exept for the fact that modern gas (with ethonal) sucks it starts to separate within a week.so if you run a tank through everyweek you are fine, but if not it causes problems, i have seen on smaller engines where after sitting a while i crapping gas would gum up the intake valve so much that when cranked over it would open and not beable to close. granted this was not a motorcycle but a ATV but i have seen it at least 3 times.
Ethanol is not that bad re separation, at least not in the typical 10-15 % zone as an additive.
It's the Methanol doped gasolines that have a harder time, solvents being needed to get it to blend in and stay in solution.
I think also that gas tanks vented to the atmosphere in humid conditions may be a further part of the problem.
Gummed up valves would make me suspicious of poor quality gasoline that has a lousy additive package in it.

mcromo44 is offline  
post #9 of 13 Old 10-05-2010, 09:46 AM
jrj
Optio
 
Join Date: Jul 2010
Posts: 806
Rep Power: 1
 
I know there used to be truth to the carbon burning. My granddad had a 73 charger way back when and he drove it 'nice' enough to get 20 mpg on the highway (318 2bbl). His plugs started fouling up at regular intervals and his mech got tired of him bringing it in to get the plugs cleaned and told my granddad to run the crap out of it once a week or so. Cleared everything up.

jrj is offline  
post #10 of 13 Old 10-05-2010, 10:03 AM
cgs
wat
 
cgs's Avatar
 
Join Date: Dec 2009
Location: Dallas
Posts: 34
Rep Power: 1
 
Quote:
Originally Posted by FlyCatcher View Post
My dad always said that when I was a kid. "Burn the carbon out". Thought he was just making up excuses to run the hell out of things. I know I always like to "burn the carbon out" once in while

Never noticed any difference in the way it runs. Guess I burn it out too much
My dad calls this an 'Italian tuneup'. We had a '78 DT175 that always seemed to run better after a couple redline bounces.

cgs is offline  
post #11 of 13 Old 10-05-2010, 12:40 PM
Pob
Tirone
 
Join Date: Apr 2010
Location: UK
Posts: 53
Rep Power: 1
 
Bear in mind folks that carburettor fed single cylinder 2-strokes are completely different from a carbon build up / foul plugs and thrash them point of view. The 919 is a 4 stroke fuel injected engine and does not make hardly any difference in carbon build up whether you thrash it or not and has tiny amounts of carbon build up over long periods - nothing to worry about at all. A 1970's Yam DT 2-stroke is a different ball game.

2 Strokes have 2 lots of oil - the gearbox oil and oil which is with their fuel which lubricates as it's used, the oil is either pre-mixed with the fuel in the tank or sprayed into the inlet with the fuel. This oil is burnt and leaves carbon deposits as it does so, also as the spent gas and oil exits into the exhaust fresh fuel and oil is drawn in - sometimes with slight overlap. 2-strokes run a lot better when their "throat is cleared". Because of the way they run most manufacturers have dropped them as they can not make them meet strict emmission regulations as they tend to be much more "dirty" engines.

Completely different types of engine.

Pob is offline  
post #12 of 13 Old 10-05-2010, 03:19 PM
Community Moderator
 
g00gl3it's Avatar
 
Join Date: Jun 2009
Location: Idaho
Posts: 11,613
Rep Power: 1
  

Awards Showcase
Wrist Twisters Event Attendance Wrist Twisters Event Attendance Wrist Twisters Event Attendance 
Total Awards: 3

What about using something like Marvel Mystery Oil for longer term gas storage and SeaFoam (very small amounts in the gas) for clearing out of deposits?

I used a bottle of seafoam in my car (1.8L Passat Turbo). 1/3rd in the intake maniford (sucked in through a cup while holding throttle at 2k RPM's) 1/3rd in the gas (full tank) and a 1/3rd in the crankcase with the oil.

Drove 50 miles, change the oil.

It smoothed out the engine idle quite a bit, and I got some mileage back. Wish I would have known about it before.

I don't know what effect it might have on an carbureted engine, but it's supposed to do wonders for FI.

Everything I read up on it, people swear by it. Every third tank or so, I put about 2 capfuls in my tank.

I'll let you know in 20k miles what it does to my engine.

2009 Aprilia Tuono - Ginger
2001 XR650R BRP (Big Red Pig)
2006 Honda 599 - Ex wrecked it :-D
2007 Honda CB900F (sold)
2006 Honda VTX 1300C (sold)
YouTube Channel
g00gl3it is offline  
post #13 of 13 Old 10-05-2010, 07:23 PM
Pilus Posterior
 
AllanB's Avatar
 
Join Date: Sep 2008
Location: New Zealand
Posts: 2,101
Blog Entries: 1
Rep Power: 1
 
Just ride the friggen thing, soft, hard, or a combo of both - it will be just fine.

AllanB is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Wrist Twisters forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome