XR Engine rebuilt now pistons hit valves : V-Twin Forum: Harley Davidson Forums

XR-Nick · 01-31-2009, 11:58 AM

After changing the pinion axel on my 84 XR 1000 (this was done by a pro) I reassembled the engine.
Now turning the engine, the rear piston hits the intake valve on the rear cylinder. As it is an XR it is the intake valve.
Only new part is the pinion axel. Everything else worked like fire before disassembly.
Cams are assembled correct, pushrods are correct, valves and rockerboxes are correct.
Is there a marking on the pinion axel for the pinionsprocket which we have missed.
Can anyone help, I´ve run out of good ideas!!

strokerjlk · 01-31-2009, 12:56 PM

Quote:

Originally Posted by XR-Nick

After changing the pinion axel on my 84 XR 1000 (this was done by a pro) I reassembled the engine.
Now turning the engine, the rear piston hits the intake valve on the rear cylinder. As it is an XR it is the intake valve.
Only new part is the pinion axel. Everything else worked like fire before disassembly.
Cams are assembled correct, pushrods are correct, valves and rockerboxes are correct.
Is there a marking on the pinion axel for the pinionsprocket which we have missed.
Can anyone help, I´ve run out of good ideas!!

did you get the lifters to bleed down?
If I were guess i say the push rod is not correctly adjusted. or the clearance was very close to begin with and your head gasket is thinner now. But since there is only one valve touching I guess push rod.

dirtrace95 · 01-31-2009, 04:15 PM

Im thinking your 84 XR has soild lifters, All my 84 stuff does. Id say do a re-adjust
on the push rods to double check yourself.

XR-Nick · 02-01-2009, 05:12 AM

Have checked pushrods. they are unadjustable. Have loosened the lifters as much as possible, but no help there. I think the clearance is very little from the beginning, as the bike is very modified. (110+ rwhp). My best guess is pinion sprocket, but what is the correct assembly. I may have to start from 0 and then move the sprocket one spline at a time till it works. There are six different possibiltys. But its hell of a job.

mjshd_1 · 02-01-2009, 02:41 PM

Sounds to me that you have the pinion gear out of time. Did you check your timing marks and are you sure it was the correct pinion shaft? To my knowledge ou can only put the pinion gear on one way. The pinion shaft is indexed so it will only go on one way. So I would use a magnifying glass to look at the timing marks or get a new gear if you cannotsee the marks on yours. Also did you use the same thickness head and base gaskets? Just my two cents.

ironheadbuck · 02-01-2009, 02:48 PM

put a degree wheel on crank and check cam timing properly -not a time to guess -

ironheadbuck · 02-05-2009, 12:24 PM

ok what happened -need entertainment -snowed in -thanks lol

XR-Nick · 02-06-2009, 02:12 AM

So far no news. Have been hit by work, but will work on soon as possible. Have a good weekend. If you need entertainment check out me and the brothers (and one sister) on www.remains-mc.dk

XR-Nick · 03-06-2009, 02:14 AM

I did it the hard way. Right side off, cams out, pinion drive sprocket off, turn it one notch clockwise, cams in, cover on, turn engine and so on, and so on.
There are seven different possibilities, the first three times piston hit valve on the rear cylinder, the next three times it hit the valve on the front cylinder, and then the seventh time it cleared on both.
Now I have to adjust valves, does anybody know how much?
I have also remounted the clutch, its the type with 6 nuts how tight shall I tighten them?