Rebuild Questions, 657x, 1995 GTX

[79MKII]

I have a 1995 SeaDoo GTX with the 657x engine and have begun a rebuild. Long story short, a crank bearing went bad and the rotary valve drive gear shredded. I decided to tear it all down for a rebuild. The top end is really nice so I'm basically just replacing the crankshaft and rotary valve shaft. I have run into so many questions during this rebuild that I thought I'd better start a thread. I've been able to find a lot of answers in other threads but not all. For example, the rebuilt crank I got today came with new bearings for the top of the rod/piston pin. I noticed that one of the rollers (needles?) was loose in the bag. Should I ask for a new bearing or can I just pop this roller back into place?

Also, new crank seal for mag side is missing the built in metal washer that the old one had. Does that matter? The pto side actually has a separate washer but but the mag side does not.



And finally to end the first round of questions......the manual references thrust washers that go on either side of the piston pins and mine didn't have any. Is the manual correct? Do replacement pistons not need them? Mine look stock but the engine has been apart before for something.



Lots more questions to come....just don't want to post them all at once. Thanks!

 

[Mekanix]

1 new crank comes with caged bearings no need for the thrust washers.
See if the one bearing will seat and stay in the bearing. If not, ask for another.
The manual is right if you used an oem bearing. But thats if you install the 38 pins and washers. New aftermarket style is just caged

2 only the pto has the retaining ring. Mag side doesn't. At least with all the new seals I've seen they don't.

 

[79MKII]

1 new crank comes with caged bearings no need for the thrust washers.
See if the one bearing will seat and stay in the bearing. If not, ask for another.
The manual is right if you used an oem bearing. But thats if you install the 38 pins and washers. New aftermarket style is just caged

2 only the pto has the retaining ring. Mag side doesn't. At least with all the new seals I've seen they don't.

Hmmm....now that I look at the parts manual, it only shows bearings.....no thrust washers. The service manual definitely shows the thrust washers. I don't think they would fit anyway because of the width of these bearings.

I tried to push the needle back into the bearing but didn't have any luck. I left the needle in the freezer and heated the bearing with a blow dryer and was still a no go. Thanks for the info!

From parts manual:

 

[79MKII]

This seems odd, but according to the manual, it is correct. For the cylinder bolts going into the crankcase, loctite blue is called for on the threads while synthetic grease is required for under the head of the bolt (#17, diagram on the left). Now, just the opposite for the head bolt....they call for loctite blue under the head bolts and synthetic grease on the threads (#10, diagram on the left).. I didn't know the blue threadlocker could be used under bolt heads??

 

[79MKII]

1 new crank comes with caged bearings no need for the thrust washers.
See if the one bearing will seat and stay in the bearing. If not, ask for another.
The manual is right if you used an oem bearing. But thats if you install the 38 pins and washers. New aftermarket style is just caged

2 only the pto has the retaining ring. Mag side doesn't. At least with all the new seals I've seen they don't.

By the way, SBT immediately shipped out a new bearing for me....no questions asked.

 

[mikidymac]

It sounds strange but just follow the manual for the way to apply sealant and threadlocker.

 

[79MKII]

It sounds strange but just follow the manual for the way to apply sealant and threadlocker.

It just seemed like it might be a mistake since they are exactly opposite, but I'll go with it! By the way, I just noticed that it was your carb rebuild thread that got me through those carbs. Very helpful....thanks!

 

[79MKII]

After reading a whole bunch of posts on crankcase sealer, I went with the ThreeBond 1211 instead of the Loctite 515 called for in the manual. The 515 is also called for in several other areas, such as the cylinder o-ring groove, for example. Can I use the 1211 for the o-rings or should I get the 515?