22cc 250r pro design = What comppression?

[jimanold22]

Hi guys anyone know what comp ratio a 22cc dome makes on a 250r?Maybe a link?Thx in advance.

[C-LEIGH RACING]

Somewhere around 180 / 190 lbs, depends on if ported & what size carb used & if the engine is in good shape.
Neil

[Kirt13]

Originally posted by C-LEIGH RACING
Somewhere around 180 / 190 lbs, depends on if ported & what size carb used & if the engine is in good shape.
Neil
I have a 30cc. You know what that might make with new CT 330 motor with new 38mm Airstriker?

[C-LEIGH RACING]

Probably about the same amount. 30cc should be a pump gas dome.
Neil

[TheFontMaster]

When I was looking at a new dome for my quad, the book I was looking in said that 21CC was the smallest you could go and still run pump gas. I don't know what the actual compression is supposed to be though.

[jas250r]

hey C, how does porting affect compression? by the way you should have your forum, just to answer 250r motor questions

[C-LEIGH RACING]

The higher you do the porting, say like if you were porting a top end drag engine, the exhaust port roof is higher & you cant trap as much volume. The amount of volume you can trap from the exhaust roof to TDC will determend the amount of compression you will end up with.
Changing the head, the squish area & dome will make a difference as well, but those two things have to work together.
Neil

[jas250r]

makes sense