No Compression

[danzoot911]

I have a Kaw 1999 STX 1100 with 80 hrs I was ridding along almost full throttle when it stopped. I was able to start it up and nurse it back to land. It would only go about 10 -15 mph. When I got it home I did a compression test and had 120 on the back two cylinders and ZERO on the front, any Ideas? Thanks Dan.

 

[Jeff Walkowiak]

Re: No Compression

pull the head and see what it looks like,, with 0 compression you probably destroyed a piston.

 

[Bondo]

Re: No Compression

Ayuh,...

Sounds like it ran Lean,+ burnt a Hole in the piston....

 

[danzoot911]

Re: No Compression

if it is the piston is the motor trashed or can it be fixed.

Thanks,Dan

 

[Bondo]

Re: No Compression

Ayuh,.. That can't be answered til it's torn down,+ evaluated....

 

[JustJason]

Re: No Compression

before you pull the head, pull the cover of the front of the carbs. Crank the engine over (with the ignition system grounded) and see if you feel air blowing back at you at the carb.

 

[danzoot911]

Re: No Compression

Thank you for the quick response, I guess I'll take it in and see what they say.

Thanks,Dan.

 

[Seadooman03]

Re: No Compression

before you pull the head, pull the cover of the front of the carbs. Crank the engine over (with the ignition system grounded) and see if you feel air blowing back at you at the carb.

You could easily do the same with the spark plug hole. Crank your engine over while cover the hole with your thumb and see if you have ANY pressure pushing back on your thumb.

you'll know when you take off your head. But then you have to find out WHY that happend...pinched fuel line, dirty/b.ocked carb. Or sometimes water does go back into the cylinder from the exhaust housing causing grooves in the piston/cylinder wall. Take pictures.

 

[JUSTINTIME]

Re: No Compression

they where known to run lean

 

[JustJason]

Re: No Compression

You could easily do the same with the spark plug hole. Crank your engine over while cover the hole with your thumb and see if you have ANY pressure pushing back on your thumb.

how on earth can you tell the difference between a piston with a hole in it versus bad reeds by putting your thumb over the spark plug hole?

 

[Seadooman03]

Re: No Compression

how on earth can you tell the difference between a piston with a hole in it versus bad reeds by putting your thumb over the spark plug hole?

I completely missed the fact that he had already had done a compression test. I apologize, hence him already knowing he has no pressure build up in the cylinder.

 

[JustJason]

Re: No Compression

I completely missed the fact that he had already had done a compression test. I apologize, hence him already knowing he has no pressure build up in the cylinder.

ahhhh.... that makes sense then. No worrys mate.

 

[Jeff Walkowiak]

Re: No Compression

the first thing he should have looked at was the spark plug,, it was probably all grey and had aluminum particles attached to it, pulling the head is a simple process and if he pulls it he will see what happened,, it appears he isn't mechanically inclined and will take it to a dealer,, who will probably pull the head and tell him he needs a new engine.