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XR80R Transmision problem. Please........

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I really hope some of the experts here can help me out here. I'm stuck to figure out what's happening.


OK, I bore and rebuilt the top end of my 86 XR80R. Partially finished post here. http://www.thumpertalk.com/topic/1160153-xr80r-top-end-rebuild/ In the process I needed to split the cases to replace the cam chain.

Doing so I had to pull all the internal components including the transmission so I could thoroughly clean everything before assembly. As the cases came apart I took pictures since this was the first time I've split one of these particular motors so I could make sure it all went together the way it came apart. Following the FSM as well as parts fiche online I reassembled the motor.

It started up on the second kick. As it ran, for a total of maybe 3 minutes on and off several times, I heard a slight noise that seamed to fluctuate in and out. BTW, when I hit the kill button the motor stopped instantly with no free spin at all.

Concerned with it I started to investigate by draining the oil and pulling the right side cover off. The new oil had thousands of tiny particles in it the followed a magnet when I waved it over the oil. Not good!

To cut to the end of the chase, I found that when I spun the primary starter gear that the clutch basket sits on that there was a drag and it felt like it was hitting on some sort of gear teeth. That's the best I can describe it.

Splitting the cases again I found the third gear & shifter fork had been grinding together wearing metal off each other. That was the cause of the filings in the oil.


With the crankshaft out of the case I assembled the transmission and put the cases together. Everything seems to spin fine and it goes through all 5 gears just fine. I've done this dry fit several times.

BUT, when I put the kick starter shaft spring on and collar in place, I can feel the drag and ratcheting against the starter gear.


I have made sure all the washers are in the right spots on the shafts for the transmission. At this point I'm lost trying to figure out what's going on. I'm obviously missing something, but can't find it.


Today I ordered all new transmission case bearings, 3rd gear and the shifter fork. But I'd like to figure out what's going on before they come in.


I'm doing the best I can to describe the problem but I'm sure I'm missing something in it. PLEASE help and ask questions that you need to help diagnose the cure!


Here's the transmission and crank all assembled just before the right case went on. The RED is assembly lube.



This is the damage done to the fork in just 3 minutes of running. Notice the bottom fork extension is the worst. This was NOT there when I put the motor together.



It's a bit hard to see but the inside edge where the fork slides has evidence of metal heated up and ground away.



This is the primary starter gear that I referred to that the clutch basket drives. It's also where the starter idle gear rides.



Not sure where to go from here. I would really like some help from someone that's done a few of these case splitting jobs on the XR80R.







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OK, lets try this to get a reply for help and advice.


All the parts have been cleaned and lubed with WD40. In the video you will here some slight gear noise due to the thin lubrication.


My main concern is if the drag and ratcheting is normal with the kick starter spring and collar installed until I put the right side case on!


I have the transmission assembled without the crank shaft in, and all the spacers/washers are in per the FSM but I only lubed it with WD40. That makes the sound a bit louder than when it has engine oil in the system.


Please watch the video and advise if what I'm dealing with is normal or some sort of problem I'm missing.



Edited by LRCXed

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