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Wing it guys

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jlaird

jlaird

Great Pumpkin
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yamaha 1200 CC engine in a Ledgend race car.

Starts great, runs good, down on power.

35 to 36 lbs compression in each of the four cylinders.

Will turn to 10K no prob, no real power though, sounds smooth and good but not agressive like it should.

Engine is sealed by authorized rebuilders.

Egn is solid state and checks good, no fuel starvation problems. Four carbs.

What the heck?? Compression is low because? Timeing is off a tooth?
 
A good possibility that it's been overheated and the rings are fried, Jack. I've seen this happen on the Legends cars before.
Jeff
 
That could very well be the answer Jeff.

Strange is it not that compression is the same in all cylinders.

And yep they do get preaty darn hot, air cooled about 5 quarts of oil, with cooler and filter. And gesh the RPM they turn. 10.5 on rev limiter.

Heh, did finish in the money yesterday, 18th of 26 even with the power loss. $80 so we went out to dinner.
 
If the rebuild used chrome rings they might not be seated.....Bon Ami time.......lol..
 
half a teaspoon down each throat at 4K RPM! /bcforum/images/%%GRAEMLIN_URL%%/devilgrin.gif
 
There ya go..Saw that done at Glamis in '70, at night, at Competition Hill....Didnt believe it when i saw it but it worked..
 
Just don't expect it to be a panacea. If the rings are fatigued from temp they're toast.


I've USED this to effect. Ya get ONE race. It ain't purty.
 
Brand new engine going in as we speek. Then will have the bad one rebuilt.

Look out sat nite, we loaded for bear.

Thanks guys.
 
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