SRX compression?

E

ecopter

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May 2, 2003
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Anyone have the round about specs. as to what compression should be on an SRX ('02)?

I got the following readings:

Mag - 132
Center - 135
PTO - 137

Thanks,
Jon
 

That's good to know. After 6500 miles, I was going to freshen up the engine, but I guess I'll put that money in my 4-stroke fund!

Thanks,
Jon
 
the exact number don't mean much, who knows how hard you pull it over.

what important is that the numbers are pretty even, you look good there.

to check for ring sealing, retest the compression after adding a bit of oil to the cylinders, it'll go up some, but if it goes way up, you need new rings
 
I find it pretty disconcerting that these compression testers seem to have such different readings from one tester to another, and "the word on the street" is that the only way to really judge the health of your compression is by comparing cylinder compression between cylinders ...are'nt these tools suppose to be percision intruments!
 
srx_eh said:
I find it pretty disconcerting that these compression testers seem to have such different readings from one tester to another, and "the word on the street" is that the only way to really judge the health of your compression is by comparing cylinder compression between cylinders ...are'nt these tools suppose to be percision intruments!
Click to expand...

there's alot of factors to doing a compression test man, how hard did you pull, what kind of ambient air pressure are you in, is the motor hot, cold, are your carbs synced perfectly that all 3 hit the top at the same time?

to many variables from sled to sled, not to mention gauge to gauge.

the compression numbers in # are usefull for some stuff tho.
 
Its not rocket science

The main differance is not how hard you pull it over, the temp or how your carbs are set, it is simply the guage quality and more importantly the area in the guage and tube, thread adapter your filling. Meaning a guage with a 1 foot hose on it and a short thread adapter will show a lower reading then the guage that screws directly into the cylinder with the correct long thread adapter on it. The spark plug hole depth and threads are more area to fill as is the hose on the guage. All in all your simply looking that all 3 cylinders are with in tolerances of each other, if they are off by more then 8-10lbs on whatever guage your using, I would look at the ring seal on that paticular cylinder.
 
I bought the gauge with the 1' hose, ...I understand I can still compare my cylinder compression with this guage, but why doesn't the manufacturer compensate for the fitting offsets and provide a true reading at the head? ...this frustrates me!
 
That would be simple for a manufacture to do, if you were to use that tool only on that given model, and for that engine only, and would only work on std bore, non ported model. Wouldnt be that much of a market for that i would think. Better to have something work on about any engine. There is no way to tell what your going to check the compression on, meaning the bigger the engine, the larger the bore, the more area its going to have and push more wind, so how would you be able to check the numbers from say a 700 snowmobile to a 454 v8 car engine??? The compression guage is merely a tool. its not exact. Its just another item to help you find your way to a problem, not a direct map like a ct scan is of your head.....lol

When ya use a compression guage if its off by 15lbs of accurate, so be it. The main thing your looking for is if they are all consistant with each other, if you check 2 at 115lbs and get to number 3 and its 70lbs, you know where to start looking for the problem, thats all the tool is made for nothing more nothing less. Dont sweat it.
 
I guess I'm getting too caught up on absolute pressure, ...and my understanding of the role of the compression tester, ...no "sweat" thx.
 
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