1997 XP Compression question

[Coopnjaxdad]

Ski has been hard to start, so I was checking some things and wanted to verify compression. Compression jumps right up to 150 in both cylinders, but the Mag cylinder reading drops after 5 seconds or so.

Does this give anyone more knowledgeable an idea where I am losing the compression? Does this sound like rings or is it a gasket issue? Does it make sense that this would lead to a no start condition?

Thanks in advance!

 

[CReynoldsMIZ]

Are you sure your gauge just isn't leaking?

 

[Coopnjaxdad]

Are you sure your gauge just isn't leaking?

I'm fairly certain, the PTO cylinder doesn't exhibit this behavior. I'll be checking it again when I get off work tonight, its possible that the gauge wasn't tightened enough in plug threads.

 

[LouDoo]

I think it's probably your gauge, they are designed to hold pressure until you release it, there's a shrader valve in the base of the gauge, replace the valve. The compression gauge in my tool box has held pressure since I last used it in early spring.

Lou

 

[Strizzo]

there should be a check valve between the screw on fitting and the gauge to hold the pressure reading. yours might be leaking off a bit, mine will bleed off slowly above 150.

 

[68ragtop]

I completley agree. Sounds like a leaky gauge. Mine will hold max PSI. Also, If it leaks out fast, you might not get max compression reading either as it could loose some pressure on the downstroke. Make sure you don't have a leak in the hose or fitting on the gauge too,
you could always test it with soapy water.

 

[kicker]

Even if the compression was leaking out of the cylinder it wont register that leak on the gauge with a shrader valve on there. The shrader valve is designed not to let air out unless the pin is pushed in.