2000 GTX RFI Hi-Temp engine shuts off

[kseidehamel]

I was out running my 2000 GTX RFI this weekend and after about 45 minutes the hi-temp light flashed and the engine promptly shut down. I towed it home and let it sit overnight. The following morning a tried to turn it over and the starter engaged but wouldn't turn the engine over and I couldn't turn it over by hand either. I then took the head off the cylinder to look at the pistons and they looked fine as did cylinder walls. Also took a peak at the rings through the rave value holes and everything looked good. After putting some 2-stroke oil in each cylinder and letting it sit, the engine started over and sounded normal. Not knowing that the issue was, I buttoned it back up and took it back out and she ran perfectly for 30mins and then shut down again. Hi-temp light was on again and now it wont crank. Jet pump was fine, I removed and spun by hand.

Could I be having heat seizure due to lack of oil? Cooling system checks out. Im leaning toward oil pump or clogged oil filter. Hoping its not bottom end damage causing heat. How do I check oil pump? I don't see any bubbles in the oil lines but I don't know how to verify if oil is getting into engine. I haven't noticed oil level dropping much, but I haven't run it much this season. Plugs look nice and brown.

Should I start with oil pump? Other ideas. Any help is appreciated.

 

[griz400]

are your spark plugs like wet from fuel -- (either one of them) -- mine did the same and was washing the front cylinder down due to too much fuel, due to a fuel injector ....

 

[- BiRkS_]

Does the ski smoke at all when running? If so, it's oiling. Also, if you looked at the cylinder walls and there is no scoring, I would look at either a stuck open injector, faulty temp sensor or cooling issue.

 

[kseidehamel]

I will put it on the hose and look for smoke and check the plugs. How do I check for a stuck open injector?

Thanks for the help so far.

 

[- BiRkS_]

If the plug is wet in that cylinder. And it has spark

 

[kseidehamel]

I took the cylinder head off again and I couldn't get the engine to turn over. Jet pump was off. I removed the cylinders and they looked great as did pistons, wrist pin and wrist pin bearings. Even with the top end torn down, I cannot turn the engine over by hand. I have a bad feeling that I have a more serious bottom end issue. There is a milky tan and white liquid on the rods.

Am I looking at a bottom end rebuild or a new engine? I did the top end with sleeves on my other identical ski but not sure its work tackling a bottom end rebuild. Wondering if I should rebuild myself over the winter, buy rebuilt from SBT or part her out. Suggestions?

 

[griz400]

i ride most every weekend,year around, i have an sbt motor for almost 1 1/2 years and going strong

 

[- BiRkS_]

Sounds like bearings are seizing up. Since you have it appart, might as well rebuild it. It isn't that hard. The most time spent will be cleaning/prepping the gasket surfaces and finding parts lol. Try to find an OEM crank, but if not, PWC engine has good deals. I've used their WSM crank on a 951 carbed ski, and its been running great. I did a near OEM build in june and was about 850$ with shipping, all said and done. Or go with the two year no fault for 1300+ shipping (~250$?)

Rebuilding your own:
Clean the cases perfectly. Get a rebuilt counterbalance shaft, or rebuild your own with new bearings/seals) Lube up the new crank bearings (I use a little gear oil on the races) Stuff the seal lips and coat the sealing surface on the crank with some lithium grease, or engine assembly lube. Use Threebond 1211 on the case halves, make sure to use a little extra on near crank seals/corners. Torque bolts to half spec, then wait 1/2 hour, then torque to spec. (this allows the gasket sealant to set up and keeps it from being squished out) Install base gasket. If the pistons are good and are within spec (with cylinders too) you may get away with a quick hone and new rings, or have them bored out and oversized pistons. Get NEW piston circlips. They can be fun to install. Just take your time. Make sure to lube up the new wrist pin bearings alot, pistons and rings and cylinders with lots of oil. Double check that the piston ring gaps co-inside with the alignment pins. Install headgasket/head, torque to spec.

Install intake, starter and fuel rail. And you're set.

 

[griz400]

i think the biggest issue is first figure why the motor is locking up, and determine all issues from that point, then actually tear it all apart and see what failed, and go from there, i think you will find, that probably only about 25 percent of all the people here will actually be able to rebuild the whole motor and have success, and if it blows again and you didnt figure out what acyually happened, you will pay out of your pocket ... again, and maybe again ...

 

[- BiRkS_]

i think the biggest issue is first figure why the motor is locking up, and determine all issues from that point, then actually tear it all apart and see what failed, and go from there, i think you will find, that probably only about 25 percent of all the people here will actually be able to rebuild the whole motor and have success, and if it blows again and you didnt figure out what acyually happened, you will pay out of your pocket ... again, and maybe again ...

Good point. Something I forgot to add. Is just what you said. Find the cause of the failure and fix that before anything else. Normally I find its more than just ONE thing, more of a chain of events. When I rebuild an engine, I go through all the systems and refresh/rebuild them as well. (oil system, fuel system, cooling system, engine mounts, jet pump, etc) Go the extra mile and do it all right the first time, then have to go back in again and redo work.