600R Grenaded / Rebuilding

[targetdrone]

My 'brother and I are rebuilding my '93 XR600R motor after it suffered a serious seizure.  We found a donor bottom end that needs a rod.  I will try to update this as we proceed. 

[targetdrone]

I cut off the rod so that the crankshaft can be pressed apart without removing the gear.  This is from the donor motor.

[targetdrone]

40ton Carolina press.

[targetdrone]

I went with a Pro-X piston and rod.

[targetdrone]

On the plus side, I will have a leftover kick starter assembly and clutch cover so someone can convert their 650L. 

[targetdrone]

My Ricky stator on the right. OEM leftover on the left. 

[Gilligans Isle]

Wow bummer. wishing you well on your rebuild. :0

[targetdrone]

Well, the crankshaft went back together nicely once we made a spacer with a notch for the shafts and grooves on the bottom.

BTW, the exhaust valves are identical to intake valves on a '98 Honda CRV, just $7 each in stock at the local parts place.

[targetdrone]

My brother trued the crank down to .001" on the short end and .003" on the long end.  I want the motor to last.  It served as a D37 race bike before it became my dual sport.

[targetdrone]

(Left)When the motor seized, the counter-balancer spun.

(Right) The replacement from the donor. 

The original could have been easily fixed if I didn't have the spare. 

[Hollerhead]

On 3/10/2018 at 6:35 PM, targetdrone said:

(Left)When the motor seized, the counter-balancer spun.

How do you verify the crank gear didn't spin as well?

Edited March 12, 2018 by Hollerhead

[targetdrone]

I had another crank to compare it to. Also the gear on the crank is a very tight press fit. I believe the Honda engineers put the round key on the counter balance to make it the weak link.

[Hollerhead]

37 minutes ago, targetdrone said:

I had another crank to compare it to. Also the gear on the crank is a very tight press fit. I believe the Honda engineers put the round key on the counter balance to make it the weak link.

The reason I ask is I bought a used one thinking I was going to rebuild it prior to tearing down and throw it in.  When I tore the engine apart I noticed the balance dots were not in the same location between the cranks.  I didn't know which one was correct so I scratched my head a little.  Neither one matched the service manual illustration.

I decided that my old crank didn't vibrate or anything strange so it must be correct.  I split the used one back apart and installed the new rod and pin in my original.  I couldn't figure out a way to get that gear off the used one without a little destruction so I chunked it in the trash.  It's definitely a tight press fit. 

Honda doesn't release the alignment information for some reason.  I guess it's because they consider it non-serviceable.  It may not even make that much of a difference as long as it's close.

Edited March 13, 2018 by Hollerhead