HELP..., Low Compression

[sxi steve]

I checked my cylinder compression on my stock 99 Kaw 750sxi pro. Front reads, 130, and rear reads, 110. :frown: This sounds low, and of course, the uneven number reading bothers me. I am good with the wrench, but not lots of experience with diagnostics. Sounds like I need new rings???? What's the stock compression supposed to be? Give me a step-by-step on the fix? What's the cost for me to do a ring job and time involved, if that's the fix?

Thanks!

 

[SuperjetSteve]

it should be 150/150... just rebuild your top end.

 

[onesojourner]

what should stock compression be on that ski. that differences is pretty big so I am sure its time for a rebuild but some motors come stock with lower compression.

 

[sxi steve]

Just got back from riding. Checked it again. 110/110 this time.

Stock should be 150/150, my understanding.

My low end need more :brap:

 

[Gainera2582]

My low end need more :brap:

Get a factory wetpipe if you don't have one already. Other than that, a timing advance plate and 9/17 skat prop will give you plenty of low end!!!

 

[Shonuff]

Finish the summer, order a new topend for the winter.

 

[sxi steve]

Get a factory wetpipe if you don't have one already. Other than that, a timing advance plate and 9/17 skat prop will give you plenty of low end!!!

What about a new higher compresion head (over the 150/150 stock compression, once top end is rebuilt). Would the new head make a noticable difference?

Yes, new pipe was in the plan for next season. Save up through winter.

 

[Shonuff]

The head will definitely pick it up. (at the cost of longevit)

 

[IceRocket1286]

Just order yourself a new top end kit and have your cylinder honed. It should need to be bored unless you did a number to it...but doesn't seem like you did. If your going to do just rings you might as well throw some new pistons in as well. They are roughly $100 a pop from Wiseco. Then you know you have a completely fresh top end, and should have no more worries with your compression.

The other accessories are up to you, but if your going to do rings, do a whole top end. Rings alone aren't worth your time....it might not really even do the trick.

Theres a GREAT guy to do your cylinder in new baltimore. Hes retired and works out of his garage and is VERY reasonable. I use him, as do many people, if your interested. You can also take it to jetcrafts unlimited in new baltimore, Mike is a great guy.

 

[sxi steve]

What's the retired guys name and number?

 

[IceRocket1286]

Ill get his number today, his name is Roger....however if you go to JetCrafts, they use Roger I believe. They are both reasonable and cheap.

 

[sxi steve]

Thanks Luke...., Good info, I have time, the ski is running good enough to finish off the season. I'll tear into it in the winter, just wanted to get my mind around it and reference some info at this point. :biggthumpup: