rotary valve crankcase grooves

[benstoker]

Hey everyone. I recently bought a 94 gtx fixer upper and have just pulled the engine on it. When I removed the carbs and rotary valve case, I noticed a chunk was missing from the rotary valve. The case looks fine (no grooves or anything) but the crankcase side is all sorts of grooved. From what I've read on here so far, if the rotary case has grooves/gouges from port to port, its no bueno and needs to be replaced or welded and resurfaced. Does the same true for the crankcase side? Whatever caused it is still in the case because I cant turn the motor over manually without a fight. Any insight you all might have would be greatly appreciated. I'm adding pics so you all can see what I'm looking at.

 

[Dr Honda]

Unless you are going to do a full rebuild... put a new valve in it... and go run.

The groove isn't good... but it wouldn't keep it from running.

 

[benstoker]

Thanks Doc. unfortunately, I am going to have to crack the case open to find out what's inside. The crank wont turn over without a fight (I was almost able to loosen the flywheel nut before it would turn over). I was originally planning on just doing a top end rebuild but once I found he motor wouldn't turn over, I decided to just go ahead and do a full rebuild. With that said, anything I should look for with regards to the rotary valve while I'm in there?

 

[benstoker]

So I finally cracked the case open today and about crapped a brick. It's not pretty as you might see from the attached pics. From what I can tell, the stator-side main bearing came apart and messed up several things. I found busted ball bearings in the stator housing and when i got the flywheel off, i found that a few pieces got caught between the flywheel and the magneto, grooving the inside of the flywheel though it didn't bust the magnet which was surprising. It also chewed up edges of the magneto. When the bearing seized, it started spinning in the bearing seat and looks like it gaulded with the outer race.

Also, I went and rechecked the RV case and confirmed that it did indeed groove the RV case face. Replacement needed?

From the pic of the case bearing seat, does it look like I need to trash the case?


Bearing pieces that were in the stator


Case gaulding with main bearing


Chewed up magneto edges


Rotary valve case grooving


What's left of the main bearing inner race

 

[benstoker]

So looking at the pics, what all am I looking to replace? Is the stator flywheel or magneto shot with it gouged up like that? What about the crankcase where the bear spun or the RV case with the grooving?

Thanks!

 

[racerxxx]

At this point, look for a good core to start with if you're going to rebuild it yourself, or send the pics to SBT and see if it is a valid core to use and ditch that hot mess in their lap. Then pick up a stator, etc.... Or abandon the project. Bummer.

 

[benstoker]

Thanks racer. I'll get them on the horn today and see what they say.