Compression

[jrs_333]

Can anyone answer? How many psi should I have with a compression tester in my 252? Right now I have 85-90 psi. I think it is low. I was told 100 psi was the magic number. If the psi went below 100 or any lower my engine would not run. I can"t get it statrted. I even pour gas dirrectly into the cylider and it still won't fire. I have plenty of spark.

[math]

I tested my engine at the beginning of the winter and i had 85 psi and it runs perfect...

[jrs_333]

Math,thanks for the info. Now i'm really baffled.. I'm not sure why this dang 252 won't run. New plug, great spark, 85 psi compression wat the hell is left. I suppose I"ll rebuild the caburetor. It should still fire by dumping some gas in the cylinder shouldn't it?

Thnx Jay

[trapperphil]

we have had that problem with one of the 444s thats wore out an we put a lil 2 stroke oil righ down the carb . it solved the problem an we was off an running . basically it boosts the compresion enuf to get it to fire .

[jrs_333]

trapperphil, I'll try that. Thanks.

jrs_333

[Barrie2777]

Gas should still explode without good compression you just won't have any power. Try heating the plug electrode until it turns red, replace the plug and crank the engine. When you crank the engine and get no fire .. if you remove the plug...is it wet?