XR55 Manual

[chris-p]

I just saw on ebay that I missed out on an XR55 parts manual. Does anyone have one they would sell?

[adam1961]

Chris,
Somewhere, I think, I have a copy. Moved and haven’t gotten to those boxes yet. If you can’t get an original, I can make you a copy if you like. Is the XR ready to make smoke yet?

[chris-p]

I have a few more motors I have promised to others before the spring, but once they are done, I promised myself I get to play with my own toys!

I have most of the XR ready now to bolt back together. Thanks to Bill Salisbury for his fine work on my gearcase! He up dated it for me with better bearings, and machined it to accept oil seals. Heck of a guy, wish I knew a tenth of what he has forgotten.

Only item I need now is the rope sheave. I think finding one will be darn near impossible. I have come to the realization I may need to fill in another models sheave, and then re stamp the model and serial number on it. I think I could fill it with weld, grind flat, then re stamp, unless anyone has a better idea?

[chris-p]

I know the rods were the downfall of this motor as well, so trying to figure out a way to strengthen them before rebuilding the powerhead. It took me years to find an XR, don’t want to destroy it.

[bh]

C; -rod failure is common with all race motors, mainly due to over reving,
especially getting up on plane, and lubrication failure.
Some also fail due to fatigue, and racers polished the rods to alleviate this.
Sending them out for ‘crack-testing’ would be a good move,
but if they fail the test, then you will need new rods any way ,
Balancing the piston/rod assembly vs each other can help.
The RACERS MANUAL by Carpenter had lots of info, if u have not seen it.
So if the clearences are right, ie; not too tight, then I would use
lots of synthetic oil, 12:1 ?, and keep the revs down .
If you don’t run it, it’s a wall hanger 🙁
-if u do and it grenades it is back on the wall 😥
-but at least you can say it ran 😀
Hoping to see it run soon.

[chris-p]

All great info thanks Brian!

I try to get every motor going, its my nature. Just don’t want to grenade a motor I know I will never find another block for!

Maybe Ill just give her a quick burst when on plane 😉

[bh]

C; -I had a PR55 here and believe the rope sheave is identical
SRs also ? It would be easy to fill in the ‘P’ and restamp it ‘X’
The #s would be close, but not right for a XR .
A SR 39 that was here had a blank plate
No #s or Model stamped on it.
U should have bought it.

Any competent engraver can do these.
Merc racing guys are always having the rare M55H(-1) front shield made from stock
M55A plates. Not kosher, but whose counting ?

[chris-p]

Great idea. On the hunt for a PR55 plate!

[Author]

Posts