Adjusting valves & Carbon

ggodwin

Member
Couple questions.
How often do you adjust your valves and do you ever manually clean carbon from your combustion chamber.

On big outboards 2 strokes we often pull the heads and scrub carbon off piston tops with Seafoam and a tooth brush. When it’s bad you loose 700~800 rpms at WOT. Cleaning them makes a big difference.
 
Rarely, if ever, will we adjust valves on our clones. If you start off with a quality spring and set the engine back to TDC after it is run you'll be fine until it's time for a rebuild.
 
Couple questions.
How often do you adjust your valves and do you ever manually clean carbon from your combustion chamber.

On big outboards 2 strokes we often pull the heads and scrub carbon off piston tops with Seafoam and a tooth brush. When it’s bad you loose 700~800 rpms at WOT. Cleaning them makes a big difference.
Clone pistons are too cheap to be wasting time scrubbing them. New one every time it comes apart
 
Valves , when you change springs , or before a big race . A few times a year if your not in the engine for any reason .
Carbon should not build up much , I have never seen a build up , then again nothing was ever together over two years without attention .
 
Nothing is better than a shaft mounted rocker like a Pred Hemi or the Champion rockers .... like Ron Popiel would say ..set it and forget it . Clone rockers are like mechanical bobble heads.
 
There’s nothing wrong or suspected wrong. Another driver told be he adjust his valves each race. I’d never heard of that being done so frequently.
Not to say anything is wrong , but if the engine was built right on the 26.5 cc minimum allowance , and there is carbon build up , it can possibly get you DQ'd . I have an engine that I built for R&D that was done just for that reason , and it started to fail the cc test after about 20 nights of racing . It was jetted a little richer than normal . Just saying , if your doing big money races where they tear you down , you might want to look at it from time to time .
 
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Not to say anything is wrong , but if the engine was built right on the 26.5 cc maximum allowance , and there is carbon build up , it can possibly get you DQ'd . I have an engine that I built for R&D that was done just for that reason , and it started to fail the cc test after about 20 nights of racing . It was jetted a little richer than normal . Just saying , if your doing big money races where they tear you down , you might want to look at it from time to time .
26.5 is minimum.
 
So basically, if the motor has a smaller cc amount than 26.5 you can get DQ’d? Which means the carbon inside is taking up some of the original cc’s? Am I reading that correctly?
 
Yes : as stated if its at 26.00 CC then there is room for some carbon build up .
A. Person could cc the engine regularly then use that as a determining factor .
Judging off what Dyno Don said . If its at 26.5 cc. . one race may be enough too
Get a build up that would or could cause DQ .
 
Yes : as stated if its at 26.00 CC then there is room for some carbon build up .
A. Person could cc the engine regularly then use that as a determining factor .
Judging off what Dyno Don said . If its at 26.5 cc. . one race may be enough too
Get a build up that would or could cause DQ .
I think you mean 27 cc. Then there is room
 
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