Oil seals in rotary/crankshaft area

[yamaha111]

Hi, I have a 1997 GSX 800. It seems to have sat for a few years before I got it last year. I had some work done to it because it seemed that the carbs were dirty and it needed a backflow pressure regulator. I put it in the water this year (the work was done at the end of last year) and now it seems to run really well for some time, and then starts to get slighlty sluggish. It has to be held wide open to start and is definitely trying to foul the plugs. I have had it to the point where the plugs have to come out repeatedly and be dried and it has to be cranked A LOT for it to fire. Starting fluid does not even help it start, and I have been told it is not a good thing to use it anyways, but I was at a loss for what to do. When it finally starts a lot of oil/gas comes out the exhaust. From what I have read (I'm new to the forum and PWCs) I could have bad seals in the lower end of my motor and this is causing oil to leak in. After everything I've checked this seems to be the problem. I'm assuming gas also comes out because I have to crank it so much to get it to start. Does this sound like the seals need replacing and what does the replacement entail? I have a lot of experience with dirtbike/snowmobile motors and my dad is an auto mechanic so I think we could handle the task. Does the motor need to come out to do it? I would greatly appreciate some insight.

 

[yamaha111]

Sorry I forgot to add that the motor hydrolocked overnight. I got it to run and the next afternoon it was locked up. I pulled the plugs to empty the cylinders and got it going again. It appears to be repeating this again as I write this. I rode it earlier today even though it was acting up, and I was able to shut off the fuel and it continued to run, I'm assuming on the oil being added to the cylinders? The petcock works fine, I tested it because I originally thought I was having a fuel problem.

 

[RX951]

The rotary shaft seals will shrink and leak oil into the intake manifold area. It begins as smoking when first cranking till the seals become so bad, they will leak alot into the intake cover area and can hydrolock the motor upon cranking if it sits up for periods of time.

A leaky needle/seat in carbs can do this too, but it will be fuel not oil.

PArt number 9 is what leaks the oil into the intake area

 

[seadoosnipe]

Crank Replacement.....

The shaft seals at the rotary valve do seem to be shot from your description. You will need to pull the motor and split the casing to get this achieved.

 

[yamaha111]

Thanks a lot for the info! I guess I have a little bit of a project ahead of me.

 

[seadoosnipe]

PM....

I just sent you a PM (personal message)

 

[robin savell lloyd]

The rotary shaft seals will shrink and leak oil into the intake manifold area. It begins as smoking when first cranking till the seals become so bad, they will leak alot into the intake cover area and can hydrolock the motor upon cranking if it sits up for periods of time.

A leaky needle/seat in carbs can do this too, but it will be fuel not oil.

PArt number 9 is what leaks the oil into the intake area

Like I have allways said I can allways be wrong. This may be something that should be considered or studied a litle bit harder as alot of us believe that the most likely problem would be the center crank seals. Can any one say that with out a shadow of a doubt that the crank seals are more likely to cause the oil leak problem than the seal #9 that Rx951 has pointed out maybe that should be tried first before we tell a person that they may have bad crankshaft seals. This is only a thought and my thoughts can allways be wrong. :cheers:

 

[derek]

the seal behind rotary valve is a possibility. BUT; this motor has a rep for eating inner crank seals, not RV seals. you can do the RV seal without pulling motor-pain but doable. it is fairly easy with a slide hammer once engine is out. might as well try it before buying a motor or crank.