2001 gtx 951 wont start

[bimmer]

Hi guys Im having a problem with my gtx it was running great and this morning dont start, I check the carbs, spark plugs, reed valves, rave valves and everything is good

 

[donkey]

so it cranks,but will not run?
have you checked compression?
have you checked for spark?

 

[SabrToothSqrl]

how did you check the reeds? you pulled the carbs? seems like a lot of work.

I'd also check fuses, and do you smell gas out the exhaust? If not, what fuel lines are in it (are they grey)? is the fuel selector ON? Is the fuel filter clogged?

 

[bimmer]

Yes it cranks but not run, I pulled the carbs and cleaned, I have black fuel lines, fuel selector on, clean filter with new o ring

 

[bimmer]

And the spark is good

 

[Minnetonka4me]

Pour a little mixed gas down the cyl and make sure it pops. Then you know if you have a spark or fuel issue.

 

[bimmer]

I did it and nothing, only smoke

 

[CReynoldsMIZ]

Sounds like you need to check your compression

 

[SabrToothSqrl]

how's the magneto wiring looking? if that's unplugged it will never start.

 

[bimmer]

in one cilinder I have 90 and the other 140, and when tried to start some times the engine go hard

 

[SabrToothSqrl]

Well, that 'should' run, but anything over a 10% difference between them means your risking damage, or it won't run at all.

 

[bimmer]

what could be the problem the gasket or the piston rings

 

[bimmer]

somebody know how the timing works in this engine? i dont exactly how it works

 

[CReynoldsMIZ]

Probably the rings, a top end rebuild "should" be the fix probably, how many hours are on the ski?

 

[bimmer]

99 hours on the ski

 

[SabrToothSqrl]

And 12 years.

It's all or nothing for a rebuild.

 

[Minnetonka4me]

It should pop with some gas down the carbs which leads me to believe you have a spark issue. Most likely a battery not putting out enough voltage when the starter is engaged. Also when you pull the plugs and check you could see spark b/c the starter doesnt have to work.

Doesnt sound like the health of that motor is very good. I would still think it would pop with some gas though.

 

[Coastiejoe]

I am with Minnetonka4me on this one..

If you have spark you should get some sort of a clue that it WANTS to run. Thus far, you really have not shown us that this is the case. I also think you have a spark issue.

That said, your compression is an issue and even if you get it running today, you will be doing some sort of a rebuild in the future.
Generally speaking, a way to determine if it is the rings compared to the vales is to do the following.

Do a compression test, lets say it's 90 psi for example. Spray some WD40 or something like that into the cylinder and do a second compression test. If it increases but a substantial amount it is the rings. If it increases only a few psi then it is the valves..

 

[Spimothy Leary]

follow all the recommendations above, definately a little more diagnostic's need to be done.

if you need a top end, I have two 951 top ends, one is a kit from SBT that I ordered 4 months ago but never used, and another that is in Mint shape, came off another ski I bought, I also have a refurb crank that is still under warranty (8 months left), and tons of spare 951 electronics/parts, etc, i'm in FL as well, but on the West coast. about 2 hours from you. I can also point you to a good local mechanic, if your willing to make the tow over to my side.

is this the same ski you had MPEM issues with 4 months ago ? was it replaced ?

 

[SabrToothSqrl]

Also thinking Spark issue + worn out engine.
for the purposes of testing, do you really need to mix gas? the oil pump should handle the oil side.

 

[bimmer]

I pulled the top end and in one cilinder I have a broken ring and other stick to the piston