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96 GTI 720 Crank Bearings, Oil Leak, Weird Noise

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KartAnimal29

KartAnimal29

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I'm new to ski's but have been around race cars and karts my whole like. So my buddy get's a sweet deal on 2 ski's and I bought the GTI from him for next to nothing. The previous owner rolled it and hydro locked it. They took the motor out and did nothing with it. We put it back together and she has been running mint for the last 10 weeks. A few weeks back I noticed that the ski wasn't using oil and seen there was some on the bottom of the hull. My buddy said just mix it 50:1 and you should be good till we take the motor back out this fall and rebuild it.

This past weekend we were out on the river and when I hopped on it Sunday morning it sounded funny. I was out riding , taking it easy , and it just shut off on me. The motor was very warm , not hot. We pulled the plugs and can tell that what ever the noise is it's coming from the front cylinder.

I got looking around on the net today and it seam I might have messed up the front bearings and seal. Thinking the oil was leaking from the front for a wile , hence the oil in the back of the hull. I never seen any oil in the front of the hull. We adjusted the oil pump the other week, lining the 2 lines up but that didn't solve the injection problem.

If anyone has an idea of what might have happened I'd love to hear your feedback.
 
Well.... if it had water in it from before.... then the bearings could have already been damaged, and you running it, just brought out the prob.


If the engine isn't locked up... take the spark plugs out, and roll it by hand. It should be relatively smooth. If it rough... there's a dead bearing somewhere.

Then.. check the compression.


FYI... seadoo's like 40:1 on the mix.
 
I've been running 50:1 Tony. Gonna rip into it later on today. I'll keep this post updated so if anyone else in the future has a similar problem it might be helpful.
 
I pulled the motor tonight and pulled the head. Looks like the back piston was hitting the head at the top side of the piston is all pitted along with the edges of the head. motor turns over find with the head off. I'm thinking crank bearing failure is the problem. I'll be splitting the case tomorrow or this coming weekend.
 
Well I got the top half of the motor off and it's a lower connecting rod bearing failure. I haven't got to crank yet but I'm going to do the bearing on it anyways just to be safe. I don't know why it wont me let me post pic so here are a few links to my photobucket page

Lower connecting rod

http://i25.photobucket.com/albums/c55/KartAnimal29/IMG_20130906_150547_zps1d51e6db.jpg
http://i25.photobucket.com/albums/c55/KartAnimal29/IMG_20130906_150557_zps44265f76.jpg

Piston

http://i25.photobucket.com/albums/c55/KartAnimal29/IMG_20130906_151139_zpse0e3b9c1.jpg

Head

http://i25.photobucket.com/albums/c55/KartAnimal29/IMG_20130906_151217_zpsb4287343.jpg
 
OK next question as I'm new to PWC's and I'm not sure what good for parts. Yeah I know Ebay, just using it as a reference. But looking around and I see a listing on Ebay for crankshaft rebuild kit with bearings and rods for 190.00. SBT has a rebuilt one for 275.00. I know for a fact that a shop isn't going to charge me 85.00 for the work they need to do if I send them mine for as rebuild. I have also seen many people, not just on this site , that say to stay away from a SBT motor. Would that go for there rebuilt crankshafts also?

Ya I know it's an older ski but the whole thing is in awesome condition.I plan on keeping this ski as it will end up being the wife's. I just want a solid piece that I'm not going to have to worry about down there road
 
I'm going to go with that the bearing or thrush washer got hot and blocked something in the oil pump, hence it not using oil for a period of time. I just got more use out of it buy mixing my gas/oil.

This was a reply to Sportster post
 
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Honestly man, buying an engine from SES or SBT is your best bet. 2 year warranty, only save maybe 200 bones if you do everything g yourself and then you also have no warranty...
 
CReynoldsMIZ said:
Honestly man, buying an engine from SES or SBT is your best bet. 2 year warranty, only save maybe 200 bones if you do everything g yourself and then you also have no warranty...
Click to expand...

I'm not is a big rush to get this going as our season is just about over and I love to work/build stuff. 200.00 or so bucks could go towards a better ride plate and intake grate :thumbsup:
 
I'd call Full Bore or SES before SBT, I hear nobody assigns core value to parts SBT has monkeyed with.

Maybe somebody can set me straight......

And seriously, you actually run 50:1 in your 2 strokes? I run 32:1 in ones that have roller bearings else 16:1 with babbitt bearings. Marine engines are heavily loaded all through the power band too, without any coasting periods, they're gonna need the good stuff and plenty of it, not like a motorcycle or snowmobobbile.
 
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Good oil goes a long way. I'm a firm beleiver in AMSOIL INTERCEPTOR oil. I'm a heavy sled user in the winter, and last time I registered my insurance, I was 15 600 km on my engine (sled has 18 000 km). I bought the sled blown, and rebuilt it. I warm it up, and run the piss out of it, especially in the powder. I used same oil in my rebuilt 951 and it seems very happy. Also have the oil injection adjusted slightly rich for break in, but very low smoke, even with the 50:1 added premix the first tank. And I pay 50$/4 litres, almost 20$ cheaper than XPSII and I can use the oil all year round in all my 2 stroke toys.

To the OP, Check out PWC engine. They have good prices. I built my friend's '01 XP with their parts (mostly WSM) He has 20 hours on the ski since end of June. Holding up great. Shipping to Canada was a chore and a half, and customer service was iffy when I had issues regarding a wrong crank sent to me, but other than that, the part's quality seems great. Use THREEBOND 1211 on the case halves. (they sell it too)

Call and get a quote from the reputable shops, but for me, I saved nearly 1000$ being in Canada. (1200+shipping-close to 200$ each way, taxes at boarder, etc) I built my engine, nearly all OEM, except piston rings and WSM gasket kit for around 850$ shipping included. So for me it was worth it.
 
Sportster-2001-951C-Stock said:
I'd call Full Bore or SES before SBT, I hear nobody assigns core value to parts SBT has monkeyed with.

Maybe somebody can set me straight......

And seriously, you actually run 50:1 in your 2 strokes? I run 32:1 in ones that have roller bearings else 16:1 with babbitt bearings. Marine engines are heavily loaded all through the power band too, without any coasting periods, they're gonna need the good stuff and plenty of it, not like a motorcycle or snowmobobbile.
Click to expand...


Can you toss me a few links to Full Bore and SES? My buddy that did the work on it said to run 50:1 as it was still using a tiny bit of the oil from the res. Like I said at first, I'm new to this game. he pretty good with ski as he buys used ,. fixes then sells them and fixes a ton during the season. We where planing on rebuilding it this fall as the ski itself is 13 years old and we have no history on the motor. I grew up watching and working on a Whelen Tour Modified Car here in New England then got into Karting, 4 cycle. This is a whole new ball game to me.Guess I'm starting to learn the hard way LOL Hey I can't really complain tho. I only payed 500 buck for the ski and have been rippen the shit out of it over the last 10 weeks. I usually go out one time during the week to a lake, maybe 4 hours , then play on the CT River on the weekend so I'd say it's payed for itself already. How does that ski run on 16:1 ? That seems like a shit load of oil
 
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- BiRkS_ said:
Good oil goes a long way. I'm a firm beleiver in AMSOIL INTERCEPTOR oil. I'm a heavy sled user in the winter, and last time I registered my insurance, I was 15 600 km on my engine (sled has 18 000 km). I bought the sled blown, and rebuilt it. I warm it up, and run the piss out of it, especially in the powder. I used same oil in my rebuilt 951 and it seems very happy. Also have the oil injection adjusted slightly rich for break in, but very low smoke, even with the 50:1 added premix the first tank. And I pay 50$/4 litres, almost 20$ cheaper than XPSII and I can use the oil all year round in all my 2 stroke toys.

To the OP, Check out PWC engine. They have good prices. I built my friend's '01 XP with their parts (mostly WSM) He has 20 hours on the ski since end of June. Holding up great. Shipping to Canada was a chore and a half, and customer service was iffy when I had issues regarding a wrong crank sent to me, but other than that, the part's quality seems great. Use THREEBOND 1211 on the case halves. (they sell it too)

Call and get a quote from the reputable shops, but for me, I saved nearly 1000$ being in Canada. (1200+shipping-close to 200$ each way, taxes at boarder, etc) I built my engine, nearly all OEM, except piston rings and WSM gasket kit for around 850$ shipping included. So for me it was worth it.
Click to expand...


Yeah I've been doing some reading on the Amsoil. Looks like it's good stuff. I'll check out PWC engine
 
KartAnimal29 said:
Can you toss me a few links to Full Bore and SES? My buddy that did the work on it said to run 50:1 as it was still using a tiny bit of the oil from the res. Like I said at first, I'm new to this game. he pretty good with ski as he buys used ,. fixes then sells them and fixes a ton during the season. We where planing on rebuilding it this fall as the ski itself is 13 years old and we have no history on the motor. I grew up watching and working on a Whelen Tour Modified Car here in New England then got into Karting, 4 cycle. This is a whole new ball game to me.Guess I'm starting to learn the hard way LOL Hey I can't really complain tho. I only payed 500 buck for the ski and have been rippen the shit out of it over the last 10 weeks. I usually go out one time during the week to a lake, maybe 4 hours , then play on the CT River on the weekend so I'd say it's payed for itself already. How does that ski run on 16:1 ? That seems like a shit load of oil
Click to expand...

Most antique boat motors must have 16:1, They don't have roller bearings like modern engines, they have bronze crank bushings and babbitt lined shell rod bearings. Even 32:1 won't work.

Your crank may have been done for before you got it, someone may have left some water in there for a few days. There's no telling.

I wouldn't run anything on 50:1, I've seen plenty of 2 strokes ring seize on 40:1 Go ask the competition riders.

Is interceptor an injection oil or pre-mix oil? I dunno, does it settle out of the fuel if it sits a couple days or temperature drops? API-TC rating?
 
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It all depends on the manufacturer's specs. But you have to remember back in the 50's oil technology wasn't half as good as it is now. I remember reading instructions for an old elgin motor that wanted SAE 30 oil mixed with the gas! Insane!

For my outboard 2 strokes (small engines up to 25 hp) I run Shell Nautilus 2 cycle oil. TCW3. Works great. I run 50:1 with a tad extra. Have a '73 merc 9.8 110 series and it calls for 50:1 from the factory.(also recommends a quicksilver/merc 2 cycle oil too) Now if you are running the thing at full throttle the whole time, or in extreme heat conditions, then I would richen up to 40:1. That is about it. As long as you warm up the engine, drive it, then COOL down (running) You won't seize up. The newer larger 2 strokes from 2000 up may have different requirements.

As for the Amsoil interceptor, Yes it meets API-TC. It is actually a snowmobile oil, so it is designed for either premix or injection up to 100:1. It won't gel until -40. Fully synthetic. Low ash. And low smoke. It meets/exceeds BRP E-Tec specs, so it would replace XD100 as well for those E-tec owners out there..
 
- BiRkS_ said:
It all depends on the manufacturer's specs. But you have to remember back in the 50's oil technology wasn't half as good as it is now. I remember reading instructions for an old elgin motor that wanted SAE 30 oil mixed with the gas! Insane!

For my outboard 2 strokes (small engines up to 25 hp) I run Shell Nautilus 2 cycle oil. TCW3. Works great. I run 50:1 with a tad extra. Have a '73 merc 9.8 110 series and it calls for 50:1 from the factory.(also recommends a quicksilver/merc 2 cycle oil too) Now if you are running the thing at full throttle the whole time, or in extreme heat conditions, then I would richen up to 40:1. That is about it. As long as you warm up the engine, drive it, then COOL down (running) You won't seize up. The newer larger 2 strokes from 2000 up may have different requirements.

As for the Amsoil interceptor, Yes it meets API-TC. It is actually a snowmobile oil, so it is designed for either premix or injection up to 100:1. It won't gel until -40. Fully synthetic. Low ash. And low smoke. It meets/exceeds BRP E-Tec specs, so it would replace XD100 as well for those E-tec owners out there..
Click to expand...

"For my outboard 2 strokes (small engines up to 25 hp) I run Shell Nautilus 2 cycle oil. TCW3."

Even though those are roller bearing engines(since around mid 1960), I think 50:1 is stretching it unless maybe you just troll around at low engine speeds. You could pre-mix and run your Seadoo's at that ratio for a while as well, you'd save a lot of oil.

Amsoil Interceptor - Isn't this a Low Ash oil, or is it? I don't think XD100 is a low ash oil, it's classified TC-W3, right? I question the idea of running a Low Ash oil in the Evinrude/Johnson E-Tec, which must be specifically programmed for either/or XD100/XD50 TC-W3, these oils are no ash and thus the engine isn't designed to sweep the ash out the exhaust ports?
 
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I think I'm going to go with SES for the crank. I also see they have a top end kit that I might go with also. I'm gonna go with the .001 over if I got that route but my cylinders are fine, no damage to them.
 
Yeah, that should be good. How about the counterbalance shaft bearings?

I usually let the machine shop decide how much bore is necessary, and I take him the pistons based on how much so they can measure the new pistons first, for a guaranteed perfect tolerance.
 
I'm just going to send them the crank and let them have at it. On there page it says send your crank and they redo it. http://www.seadooengineshop.com/seadoo-crankshafts/

If I do end up getting the cylinders done I'll send them at the same time and have them do everything at once. Like I said I'm not in a big rush as the season is pretty much done up here in CT. If I want to go out I can use a buddies ski or just jump on a friends boat. The CT River will start to get cool quick with theses cool night's we are having right now and if the rain picks up it will cool even faster.
 
There is no counterbalance on the 720. I didn't remember seeing one and just went in the garage to have a look and there is none. You got me thinking LOL
 
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