Cranking slows then stops

[boudreauxm]

I recently came across 2-93' SPX models. They have both been sitting unused for about three years. Before trying to crank either one I cleaned out the fuel tanks, pulled the old batteries, pulled the plugs, etc. One of the two I was able to start and ride with a minimal amount of mechanical problems. The second ski has thrown me for a loop. I eventually found alot of 2 stroke oil in the crankcase and sucked it out as best I could with a vacuum pump. I also pulled the top of the head off to check for rust on the cylinder walls and they look good. After putting the head back on, the engine will turn over well for about 10 seconds (spark plugs removed) then it slows to a crawl, the problem has not changed. At that point I cannot turn it anymore with a wrench, however if I turn it back the other way about 2 revolutions it frees up and will turn over again for another 10 sec or so.It will not turn over at a normal speed with the plugs in. I have plenty of battery juice going to the starter. Not sure what is going on here. Im assuming there is more oil which might be causing the problem. If so is there a way to get to it? Any help would be appreciated.

 

[seadoosnipe]

Rotary seals....

If your having a problem with oil in your crankcase, then you may have bad rotary chamber seals. The rotary is a worm gear located directly in the middle of the engine. There are two hoses, one supply, one a vent, that keep this gear in an oil bath. If your filling up the crankcase, you should also notice a big drop of oil in your injection tank.

 

[Vicious]

Heat might be the issue here.... make sure you have oiled your cylinder heads. If you are cranking on an un-lubed (dry) cylinder walls you can cause damage to them by the friction heating up the cylinder walls.

Try to add some injection oil or spray WD-40 in them to lube them up through the spark plug hole. Make sure both pistons are near the middle because a low piston will just let the oil run out. Have you checked the compression?

Vic

 

[boudreauxm]

I have located the two oil lines you are talking about and I agree there is probably a seal problem. Since it was not run for a few years and the oil tank is about half full I am assuming it leaked down. My problem is getting it turning over normally. If I have to go to mix and abandon the oil injection I will do that. Do you know how I can access the oil in the bottom of the case?

 

[kustomkarl]

The injector oil isn't the problem. The engine has a Rotary Shaft and Gear in the cases. It is driven off the crank. on either side of the crank is a oil seal that keeps the oil that lubes the Rotary Shaft Gear from seeping into the combustion chamber area and adding more oil to the fuel mix ratio. The oil line that feeds the lube goes to the same injector tank as the injector oil. You have to have this oil line attached or the engine will self destruct. To repair the oil seeping into the combustion area...you have to remove the engine, split the cases and rebuild the seals on the crank. It will only get worse and the choices are to rebuild for about 300-$400.00 or get a re-manufactured engine and replace the hole thing...cost about $800.00. Here is a company I have heard about that does that" www.sbtontheweb.com " Keep us posted if we can help out anymore.

Karl

 

[robin savell lloyd]

This is not mine and may not be your problem just a thought from SBT The 587, 657. and 717 series Rotax engines use a Mikuni injection pump with external one way flow check valves, mounted to the pump via banjo fittings. Many times if the valve does not seat properly for what ever reason, you will end up with a crankcase full of oil. This will normally not occur overnight, but will show up over a period of time, specifically when the ski is stored for any length of time, longer than several weeks. Numerous times in the shop, our junior techs would assume that the RV seals have failed, only to perform a pressure/leakdown on the crankcase and find nothing wrong. The next step would be to inspect the injector pump, and invaribly one of the two check valves has stuck open.
With extremely long term storage skis, this can result in oil filling both cylinders, as the oil will penetrate beyond the RV and into the covered intake port.

The Sea-Doo part number for the check valve is 420956010 MSRP is $8.43, the sealing washers are 404146600 MSRP $0.67.

This would be a good time to replace the injection hoses 414413800, MSRP $0.79 per foot and clamps 290853843, MSRP $1.24.
Hope this may help someone one day. good luck Robin :cheers:

 

[boudreauxm]

The injector oil isn't the problem. The engine has a Rotary Shaft and Gear in the cases. It is driven off the crank. on either side of the crank is a oil seal that keeps the oil that lubes the Rotary Shaft Gear from seeping into the combustion chamber area and adding more oil to the fuel mix ratio. The oil line that feeds the lube goes to the same injector tank as the injector oil. You have to have this oil line attached or the engine will self destruct. To repair the oil seeping into the combustion area...you have to remove the engine, split the cases and rebuild the seals on the crank. It will only get worse and the choices are to rebuild for about 300-$400.00 or get a re-manufactured engine and replace the hole thing...cost about $800.00. Here is a company I have heard about that does that" www.sbtontheweb.com " Keep us posted if we can help out anymore.

Karl

Thanks for the info and advice. I'm still a little confused. I understand the oil seepage problem I will have to decide on, however do you think the oil is causing the crankshaft to stop turning, then when I turn it back wards manually the oil is forced back, because all of this happens with the plugs out and/or the top of the head off. If I have to change the oil seals I will but I would like to make sure the other problem will be fixed as well. Thanks again

 

[robin savell lloyd]

Sory I did not read your post correctly. you do not seem to have a oil problem only. you also seem to have another problem like bad crank or rod. good luck. :hat:

 

[Fields]

Boud I had very similar symptons

I recently rebuilt my carbs I had very good compression when i started , the ski I bought had set up for two years. The carbs turned out to be the easy part, After reasembling every thing the ski ran perfect in the yard.

Took it to the river and it was hard to crank, but it cranked it went about 50 yds from shore. Brought it home and the spark plugs were fouled out, noticed that it would spin over and then all but quit spinning over, Sprayed a can in each cylinder of wd40 and mystery oil. Still was not turning over with my hand with the plugs out , noticed noise also when i spun it over,

Removed head and found the rear cylinder the rings stuck to the piston , removed the head and found the crank is the culprit for the noise,

In the market for another ski now.

 

[kustomkarl]

Thanks for the info and advice. I'm still a little confused. I understand the oil seepage problem I will have to decide on, however do you think the oil is causing the crankshaft to stop turning, then when I turn it back wards manually the oil is forced back, because all of this happens with the plugs out and/or the top of the head off. If I have to change the oil seals I will but I would like to make sure the other problem will be fixed as well. Thanks again

It sounds like the second part of you problem is the rotary shaft itself or maybe a rod...either way it sounds like a swap out is in order. Still SBT might be you best cheaper bet. No matter what else is wrong ...you still should swap out the engine...as it's not worth it trying to repair it with such serious damage.

Karl