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1996 XP Compression

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That scoring on the side is from the RAVE valve, that's a heck of a clearance to have .52 mm difference between the cylinder and the piston. An overbore beyond 82.25mm is a risk of the RAVE hitting the piston, unless trimmed. In my case of the 97' GTX, this is exactly what happen, untrimmed RAVE's with 82.50mm overbore pistons. Eventually punched a hole on the side of one piston, locked it up, and it filled up water when towed, then it sat for a year.

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Yeah, I'd pull it and break it down and have a look, especially if you're about to spend money on the top end. Would suck to do it again.
Rave valves were definately rubbing on both pistons. I'm going to properly shave them down this time. I don't have my shop manuel with me right now, how much more work is it to split the crankcase and replace the seals? Only thing left on the engine is the driveshaft and oil pump, so I don't think it would take much more to completely pull it. Any special tools besides the alignment tool? And will I need to re-do the rotary valve if I split the case? Appreciate everything guys, you are a wealth of knowledge.
 
You need to get the mag flywheel off to disassemble the lower half, might need to get the flywheel puller tool, I broke a bolt on my steering wheel puller and nearly hurt myself on my second 787 build. Only then did I fork over the $20 for the tool. You'll need to set the rotary valve timing upon reassembly, I'd recommend a degree wheel to make it easy.

You'll need a gasket set, you need one for the top end anyway, just get the complete engine gasket set, comes with everything, including carb base gaskets, which you'll need when you put the carbs back on.

Once you get it apart pay close attention to the bearing conditions on the balance shaft and crankshaft. If any are noisy like a roller skate, address it. Core swaps for cranks and balance shafts are available, usually the most economical way to go. I wouldn't buy and install used parts to save money.

You'll need to get something like Three Bond 1184 or similar for the case halves upon reassembly, and either 515 or 518 loctite (aval from NAPA) for all the bolt threads and the like where it's called for. Follow the Service Manual to the T when doing reassembly and ask questions on here when you have doubts.

Yep, highly suggested to get the alignment tool after you put the engine back in, otherwise you could have expensive problems later if you skip alignment.

It's not a difficult job, where people go wrong is they rush through it and skip steps and don't verify things as they go along. You don't want to half ass it, it'll be the difference between a great running ski for many seasons right out the gate or nothing but run issues and break downs getting stuck on the lake needed a tow, which then becomes wasted time and more money to get it right.
 
Thanks for all the advice! Ordered all of the sealants/gasket maker. Waiting to order the gasket set so I can get the pistons as the same time, still waiting on the machine shop to know what size I need. I almost have the engine pulled, but am having trouble removing the drive shaft. I was able to remove the jetpump (after 2 hours of prying and fiddling due to it being glued on with silicone). The "floating ring" is my only hold up. I can't seem to move it to remove the o-ring on the shaft. Any tips for that?
 
You need to remove the sealing ring before the pump. Without the pump in you have nothing to push against.
I figured I would either need to reinstall it, or make up some kind of bracket that will hold the drive shaft in. Once that's accomplished, any tricks to move the ring back to get the o-ring out?
 
Was able to pop it off and get the engine out. Looks like there was some water in the mag side. Can't wait to see what the rest looks like!
 

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Alright, ended up doing a full rebuild. Everything is back in, aligned, hooked up, and ready to go. Fuel is premixed in the tank, carbs are rebuilt. Is it ok to do a first start on a hose to make sure it runs? I understand you can not break it in on the hose. Just want to make sure it starts before I take a long drive to the lake.
 
My first start I don't do on the hose. I only let it run for a couple of seconds. You're basically just getting the fuel where it needs to go, verifying timing, spark and all that. If it cranks, my next place to go is put the ski in the water and do all the checks there. Good Luck. Be gentle.
 
My first start I don't do on the hose. I only let it run for a couple of seconds. You're basically just getting the fuel where it needs to go, verifying timing, spark and all that. If it cranks, my next place to go is put the ski in the water and do all the checks there. Good Luck. Be gentle.
Cool, thank you!
 
Quick update with some issues. Was breaking the new motor in and sprung a leak from one of the cast plugs in the exhaust. Was able to get the jetski back, but it did pull water in to the PTO cylinder and hydrolock. Got it home, blew all the water out, and ran it on the hose to get (hopefully) all the water out. Exhaust is fixed and back on the machine now. It will run, but has a pretty bad miss. Put new plugs in, and it is still missing, but less. Is this most likely a carb issue, or electrical somewhere?
 
Check compression. If it hydo- locked you could have blown a head gasket. Othewise just put it in the water, be gentle and ride it. I doubt you got all the water out and it needs to be ridden for that to happen. Good Luck !!
 
Check compression. If it hydo- locked you could have blown a head gasket. Othewise just put it in the water, be gentle and ride it. I doubt you got all the water out and it needs to be ridden for that to happen. Good Luck !!
I did, both cylinders were good, sorry for leaving that out. The miss isn't going to hurt anything, and could be caused by the water? Thanks.
 
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