01 gtx locked up. Potential causes

[jcross312]

Hello all,

About a year ago I drug my '01 GTX to the river to give it a spin for the first time that season. I ran it fairly hard up the river about 5 miles. It seemed like it was running a little lean and cutting out every now and then. I thought maybe it just needed to be ran some. Anyway, after about 5 miles I let off the gas. That's when I heard the death knock. I knew I was in deep s#!÷ and tried to run slow back to the dock...Which lasted about 5 seconds before it locked up. Finally a year later I pull the motor and tear it down. The front piston is broke at the skirt and the big end of the rod has melted and split in two. Probably as close to slinging a rod without actually slinging a rod. May have damaged crank bearings also, haven't got that deep yet. The rear rod seems fine though?? What would have caused the front connecting rod to size and melt? Motor has about 200 hours. Running 93 octane with quicksilver full syn pwc oil. Thanks

 

[mikidymac]

Dirty carbs running the engine lean. When it first started to run bad like you said "lean" you should have stopped. Continuing to run it thing it will clean out always results in a blown engine. You will have to replace the crank for sure. And with 200 hours it's ready. It's also possible that something mechanical just let go. 200 hours is at minimum time for a top end and the pistons could have just fatigued.

 

[snikwad003]

What color are yer fuel lines

 

[jcross312]

Grey...and the cable running to the oiler? Was broke when I pulled the engine

 

[mikidymac]

The cable to the Oiler being broken will make the pump go full rich so that’s not the problem. Grey fuel lines = dirty carbs = blown up engine.

 

[snikwad003]

Well at least you don't need new cases. Fuel system rebuild and new guts in your motor and you'll be back on the river.

 

[Rabid]

Do they have kits with everything or do you order each piece? I'm getting close myself on the 97 GTX.

 

[jcross312]

Thanks guys. Thinking about doing it myself. I've replaced cranks and topends in dirtbike motors several times and have a shop with alot of basic and not so basic tools. Looks fairly straightforward. But having the pros do it with a 2 year warranty is pretty tempting too.

Also, what the heck happened here. This has been like this for awhile I think. Bought the ski with 120 hrs and could tell the exhaust had been removed. Had red rtv where the pipe connected to manifold, but head nuts were not touched. Now I see part of the exhaust manifold inside is broken. ??

 

[snikwad003]

If you can handle a dirt bike transmission then this will be cake. Save the money you would spend on that warranty and get you some quality parts. OEM reman crank, I perfer pro-x pistons because they're quality and not forged and a good gasket set. This is the worst time to try to send a motor any where and sbt uses some China parts alot of us don't like.

 

[jcross312]

If you can handle a dirt bike transmission then this will be cake. Save the money you would spend on that warranty and get you some quality parts. OEM reman crank, I perfer pro-x pistons because they're quality and not forged and a good gasket set. This is the worst time to try to send a motor any where and sbt uses some China parts alot of us don't like.

What about the cylinders? Oversize pistons and bore? Or ?

 

[mikidymac]

Yes, bore oversize. You will also need to rebuild the balancer shaft.

 

[snikwad003]

I like pro-x parts, I don't have them in any of my watercraft yet but I beat the chit out them in my kx250