130psi compression (is this bad?)

[Keith]

Your compression seems low however they are almost the same. Doesnt matter what guage you use (snap-on, craftsman, autozone, bla bla bla) You want the numbers to be as close to the same as possible. Leave it alone and ride it.:biggrin:

 

[oxnard111]

I have used a crappy compression guage that worked perfect on my car (175lbs on each cylinder) but when I put it on my SXR it only gave 124lbs on front 121lbs on back.

Then took to a shop, they used a snap-on and the difference was exactly the same (3 lbs difference between the same cylinders) but was 165lbs on front and 162lbs on back.

Kinda weird that the difference betwen cylinders was exactly the same for each compression guauge but just about 30 lbs off between each other.

 

[2002zxi]

maybe he was joking!

I was drinking severly the day we checked them...

so it could have been 230 in hole, and 8 psi in the other.

:dunno:

YES! I just made those numbers up, judging from how well the black ski was running:cheer2:

 

[sflsurfrider]

Your compression seems low however they are almost the same. Doesnt matter what guage you use (snap-on, craftsman, autozone, bla bla bla) You want the numbers to be as close to the same as possible. Leave it alone and ride it.:biggrin:

i disagree. if you have a high quality guage and youre reading 57 lbs psi in each hole, you dont leave it alone and ride it.

but, i see what youre saying. youre right for the most part. youre looking for consistancy. but if the numbers are REALLY low (with a good guage THATS NOT LEAKING), its worth a looksee.

 

[Mouthfulloflake]

he had a cheap guage, and a cheaper helper ( me)

130-140 in each hole

would porting make it read low?

 

[2002zxi]

he had a cheap guage, and a cheaper helper ( me)

130-140 in each hole

would porting make it read low?

after a case of the beast lite, you should have seen where he put the gauge. :Flush:

Really though, that ski rocks... but what's the deal with the compression? It's supposedly ported. If I pull the head will there be some sort of identification I can look for to see what head it is?

 

[keefer]

The domes should be marked with their size in cc. Like I mentioned before, with a 81mm bore you should be getting around 180psi with 35cc domes if they are unmodified. Your consistent readings are a good thing, but I personally like to get a real number when testing. That is why I nutted up and bought a Snap On guage and get the real deal. Takes the guesswork out of things. Your engine is probably fine but you wont really know unless you get accurate readings and then make the decision whether the compression is low and maybe the rings are worn. You could always pop the head and give it a look inside. It looks like an ADA head with O-rings. Easy Off, Easy On.

 

[jetskiking]

Here is an idea. Hook your guage to a compressor and check it?

 

[Mouthfulloflake]

after a case of the beast lite, you should have seen where he put the gauge. :Flush:

Really though, that ski rocks... but what's the deal with the compression? It's supposedly ported. If I pull the head will there be some sort of identification I can look for to see what head it is?

dude, sorry if that guage hurt you.

I thought you said you liked that?

hahahaha

hook it to my air compressor and check it cool.

air compressor at my house.
guage at lake house.

hmmmmmmmmmmmmmmm

guage is lighter than the compressor, Ill bring it home and check.

 

[Keith]

When you change the height of the exhaust ports doesnt that have an effect on the compressinon? Wouldnt it cause the compression to drop?

 

[gj_fx1]

This is exactly why you never see hard numbers for compression on two strokes, the port opening throws a wrench in the works...
It wouldn't surprise me if some port jobs raise it and some lower it..