2 Stroke 1998 CR80R

[Trfsrfr]

CDA and his dad was there. Should have looked him up.

That would have been cool. Next time.

@Gary- thanks for the shim idea, it worked.
Is the case junk with these cracks? They're all over the cases. See below;

 

[Mihylo33]

That would have been cool. Next time.

@Gary- thanks for the shim idea, it worked.
Is the case junk with these cracks? They're all over the cases. See below;
View attachment 30499

Looks like just casting cracks from the mold. Should clean up with some scotchbrite

 

[PALMER84ONE]

Casting marks as Mike said. Carry on!

 

[Trfsrfr]

Excrement!
So glad I went with the whole rebuild kit. The main bearings are shot and definitely the noise I heard when it ran.

 

[PALMER84ONE]

Excrement!
So glad I went with the whole rebuild kit. The main bearings are shot and definitely the noise I heard when it ran.

 

[Trfsrfr]

I pick up the case, cylinder, and head from the machine shop today.
What is the preferred method of assembly and break-in for this thing?
I have a tub of Redline assembly lube if needed...

 

[PALMER84ONE]

Trans, crank in right side, clean case halves real good with a clean cloth and CRC brake cleaner. I get mine from wallymart. Put bond on left case (unless it has angasket and doesn't call for it) and draw together with crank puller.
Brake in:
I prefer a few light heat cycles with 20-25:1, drain remainder, fill with 32:1 and then let it rip.

 

[Trfsrfr]

Okay to pack the bearings with assembly lube?
Or is that only a 4-stroke thing?
After I got it home from the machine shop I see that a couple of the bearings were packed with some blue stuff of some sort, feels like grease...

 

[Trfsrfr]

I got the trans installed and the cases put back together but I feel like I am way over-tightening the case bolts.
According to my manual it says for 8mm flange bolts to torque to 20 ft. lbs, but I feel like I am going to strip the case, or snap a bolt, especially the longer ones.
Right now I have them at about 130 in lbs, and even that feels like a lot.
Does 20 ft. lbs sound right to you guys?

 

[SRAD97750]

You most likely are referring to a 5-6mm flange bolt. (7ftlbs)
The shank of the bolt determines it's measured size. The hex head measurement is completely arbitrary. -BIG DAN

 

[Trfsrfr]

You most likely are referring to a 5-6mm flange bolt. (7ftlbs)
The shank of the bolt determines it's measured size. The hex head measurement is completely arbitrary. -BIG DAN

View attachment 30531

Ok, thanks Big Dan.
7 ft lbs sounds much better.

 

[Trfsrfr]

Okay, moving right along;

What do you guys recommend for piston ring endgap?
Service manual says .011 to .017.
Right now it's at .0125 so I assume I should just leave it at that...

And then I have heard different theories on installing the piston;
I heard dry, and then the manual says to lubricate all sliding surfaces.
What do y'all recommend?

 

[Mihylo33]

Okay, moving right along;

What do you guys recommend for piston ring endgap?
Service manual says .011 to .017.
Right now it's at .0125 so I assume I should just leave it at that...

And then I have heard different theories on installing the piston;
I heard dry, and then the manual says to lubricate all sliding surfaces.
What do y'all recommend?

Your doing fine. I always reassemble using tranny fluid best assembly lube ever according to this old engine builder I knew.

 

[PALMER84ONE]

In the trans I use trans oil for assem. In the jug I use the same premix I am going to run. Ring gap should be followed per manual.

 

[CDA]

As stated, I run a little premix oil around the cylinder to help drop the jug on. After that, I run the piston up and down and wipe off any excess.