Ebay rebuilt 717 engine vs new sbt 717 vs bottom end rebuild | ENGINE FLOODING WITH OIL

[nbaddorf]

Hi, I have a 1996 Seadoo GTI, with a big problem of leaking oil into the cylinders. I have thoroughly gone through the carburetors, and know they aren't leaking fuel. Even with the fuel selector switch turned off, both cylinders fill with a puddle of oil within 1 minuet or running. I have removed the oil injection, and therefor have deduced, along with other members on this forum, that I have a leak in the bottom end of my engine.

(More in-depth backstory) - I have read many forums about similar issues like this. They all refer to having a geyser of oil fly out of the ski when the plugs are pulled. I have never had lots of oil come out. Many people also have hydro locking issues due to the oil. I have never had an issue with that. The other people I have read about seem to have this issue only initially, then the ski burns all that oil up, and it runs great again. As for my ski, I get a puddle of oil in each cylinder after 30 seconds of running, causing it to die. I have never herd of people having a leak as bad as this. Am I missing something?

So, I am wondering what your experience/recommendation is of 1. buying a refurbished engine off Ebay. 2. Buying a new engine on SBT. 3. Trying to rebuild bottom end of my engine myself.

With options 1 and 2, I am wondering what there quality is, and if I will likely have problems with the engine. As for option 3, I am a 16 year old guy who is willing to learn, but has limited funds, tools, and knowledge. My worry with option 3 is that I will incorrectly rebuild the bottom end, and spend as much money as it would take to buy a new engine.

Thanks for your help, I have been working on this thing for almost a year and really hoping to get to use this this year.

 

[mikidymac]

It is very strange that it only happens when running as typically crank and rotary seals cause the most leaking when sitting.

I think to rule out the oil pump I would disconnect it and try premix for a 1/2 tank and see if it is still getting too much oil when running.

 

[nbaddorf]

I already removed the oil pump a while ago, thinking that it might be the problem.

 

[mikidymac]

Then it can only be the rotary seal or the crank seals.

 

[nbaddorf]

Have y'all ever used seal rejuvenator? Do you know if that is bad for the engine or would that maybe help my problem?

 

[mikidymac]

No, will not help.

 

[nbaddorf]

Ok, thanks. Quick question, I am in the process of pulling my engine apart, and I am trying to take off the PTO flywheel. I found the special bolt things that fit into the pto to help take it off. Do you recommend those? Also, in the seadoomanual, I was reading something about having to time the PTO flywheel. If you don't mind, could you explain how to do that? I was confused by the manuals instruction. Thanks so much!

 

[mikidymac]

If your talking about the rear flywheel (PTO) I prefer a chain wrench and locking the rear piston with a block of wood.

No, no timing on the PTO, it just threads on.

 

[nbaddorf]

Ok, so I just was looking at my engine (which is currently all taken apart), and I noticed that the rotary valve has scoring and a divot cut by something that must have gotten in the bottom end of my engine. I also noticed that, when turning the crankshaft by hand, the RV doesn't move at all. Just checking here, but the RV is supposed to move, correct? if so I guess I have something majorly wrong in the bottom end.

 

[mikidymac]

Yes, something locked up the rotary valve then stripped the brass gear on the rotary shaft that is turned by the crankshaft.

You will have to pull the entire engine apart.

 

[nbaddorf]

Well, the only good news there, is that the engine is all apart already, because I was planning on training it in with SBT for a new engine. Is the brass gear an easy fix, or will it be hard/costly?

 

[mikidymac]

You have to split the cases and inspect the crank and rotary shaft for damage. Sometimes when the brass gear strips it bends the shaft and dislocates the crank gear.

 

[slatere17]

I'm curious to hear what you find with the crank, rotary shaft, and RV seal, especially if/when you split the case. The rotary shaft damage must have damaged either the RV seal, or both crank seals for you to have oil in both cylinders.

FWIW, I have a 98 RFI that has a badly leaking inner crank seal (MAG side) with all the symptoms you mentioned in your original post. It fouls the spark plug, causing a rough idle and eventually stalls. But it is definitely only the 1 cylinder. You have a bigger problem with the rotary shaft.

 

[nbaddorf]

So would y'all recommend that I open the bottom end or just replace the engine? I am trying to mix saving money with hopefully having the ski working in the next 3 months.

 

[slatere17]

Rarely an easy decision. As a gearhead, I usually lean towards self-performing so that I can't blame anyone but myself if things go wrong. If you make a mistake during the rebuild, and it trashes the block, are you prepared to deal with that? Does rebuilding the engine yourself sound interesting? If not, might be a better choice to go with a replacement.

You could also split the case to get a better idea of what you're dealing with, then make a decision.

 

[nbaddorf]

I am also a gearhead and normally I would take this engine apart and all that, but I am 16 and this is a dream jet ski I have wanted for many many years. The jet ski is draining more money than I can make, with all the problems I have found, plus buying tools. I don't really have the funds to mess up an engine rebuild or to buy all the tools needed at this point. Like you said, I don't think I can deal with myself trashing the block, partly because I don't have the funds to buy a new engine without core trade in.

With splitting the case, do I have to remove the top end of the engine? If it is as simple as just unbolting the bottom end of the crankcase, then I can do that, but I don't have all the tools to reassemble the top and bottom end.

 

[nbaddorf]

Ok, well thanks for your help! I bought the new engine, which is supposed to come in around 9 weeks. Meanwhile, I had a question about reconnecting the jet pump to the ski. I already pulled the pump off the ski, and it had the silicon. My question is, where and what type of silicon do I need when I connect the pump to the ski?