New Rider, Old XS650 - A Begining

[weekendrider]

There is a hidden bolt in the cases behind the clutch.
Look at this thread, post number four.
http://www.xs650.com/forum/showthread.php?t=1411&highlight=hidden+case+bolt
The first picture shows it. It is also identified a few pictures down as number 9

Sidebar: has anyone got info on a heel toe shifter like on the motor in the German manual? The one used for pics.

 

[Shadow24v]

Ahh, I figured one was hiding somewhere...

Now I'm stuck again though. Can't get the clutch hub nut off. Tried holding a couple friction plates in the basket with channel-locks to no avail. Tried putting it in gear and holding the sprocket nut and hub nut, no dice, even tried jamming some plywood between the sprocket and case...all it did was chew up the wood. even tried heating it a bit. I know I had it off about a year or so ago to fix the starter gear, but it's being obstinate now.

Anyone have any other advice that won't cost $60 for a new electric impact? I was thinking of getting a couple C clamps to better clamp teh friction/drive plates together, but I think I'll end up with the same predicament...no leverage.

 

[XSLeo]

There are several home built tools jsut for this purpose in the Home made tools thread in the XS650 TECH section.
Leo

 

[nj1639]

That nut can be a bear. I belive that I put the bike in gear and gave it the breaker bar and whacks with a rubber mallet....shock whacks. It did come off.

 

[Shadow24v]

Yeah, I think the in-gear method was what I used last time...didn't think to loosen the sprocket and clutch nuts before taking the motor out of the frame...

 

[weekendrider]

Try a filter strap wrench to hold the clutch while you do the deed.

 

[Shadow24v]

lucked out, got a coupon in my email for the harbor freight electric impact...30 seconds and both nuts were off. Gotta love the right tools!

 

[gggGary]

Considering hte cause of this tear down I thouhgt I would mention pete is very close to production on an electronic advance, toss the points AND the advance mechanism. Holed pistons are common in points engines. a lean out can do it to but I think over advanced spark leading to detonation is a prime suspect. If one piston is holed the other should be carefully checked for signs of detonation, though I didn't see any in the pics?

 

[Shadow24v]

I saw rumors of Pete's advance system, but haven't found any info on it yet...

The left side piston seems to have escaped any damage, but i have a matched set of .953 pistons to replace the .952's that were in the motor. I'll know more when I get the jugs cleaned and mic'd whether they will work or not.

I am pretty much certain an over-advance / lean condition was the demise of the right side (bob weight ears were out of spec by at least 1mm). It was also under a heavy load condition that the piston died.

 

[Shadow24v]

Well, got the case split and mostly torn down. AFAICT the trans and crank bearings are OK. No real slop, catches or anything. There is some wear on a couple of the dogs, but nothing major. Crank seems fine as well. I probably will just clean the cases up and re-assemble. I'm leaning towards soda blasting as I don't think the cleaner I have (heavy lye content) is good for the job considering lye's interaction with aluminum.

 

[Shadow24v]

Well, tested the cleaner and it doesn't seem to have any adverse reactions to the aluminum of the case. Spent a coupe hours with a big bucket of elbow grease, brushes and the cleaner. not perfect, still got some crud in obscure pockets and the like, but more than good enough for re-assembly and such.

Pre-cleaning

cleaned case

Even got most of the right combustion chamber cleaned up. the aluminum flecks from the dead piston came right off the steel insert.

 

[Shadow24v]

Well, another weekend and more progress! got the head and jugs cleaned up, more or less. I decided that since this was going to be a regularly ridden, non-show quality bike, they aren't perfectly clean. But they are a heck of a lot cleaner than before...got a whole lot of oily grime dirt off of them. Also got reminded how sharp machined case edges are...twice...

I was also able to de-carbon the combustion chambers and clean the ports a bit. Still have to clean the valves some, and probably lap them on re-assembly as well. The exhaust valves and seats look a bit worse for wear, but not bad enough to warrant re-cutting or replacement valves. Additionally, the exhaust valve stem seals were a bit DEAD, which I believe lead to the high carbon content in the exhaust ports and possibly the CC as well.

I probably will take the jugs to a local shop to have them mic'd for roundness and to compute the bore to piston clearance. I'm leaning toward the Honda piston rings as well.

still drying, but much less grimed up...

Also came up with a decent DIY valve compressor with enough access to remove or replace the keepers...something about necessity and the mother of invention?

 

[Shadow24v]

Took the used pistons I snagged off of ebay and the jugs to a local machine shop for measuring (don't have accurate enough micrometers etc...yet) and got bad news. Both bores had out of spec taper and were out of round. The used pistons were also worn to where the piston to bore clearance was beyond service limits.

Sounds like I'm in the market for 1st over pistons and rings at this point. Speaking of pistons, do we know who makes the 1st over pistons from Mikesxs? As far as I know, Wiseco only makes the big bore pistons, and I don't recall if any of the other piston companies have made XS650 pistons yet.

 

[Shadow24v]

Cleaned up the last part of the case and started working on other Mics. stuff for the time being. Did discover what I think is the 4-5 shift fork with some bad wear on one of the tips... Also it looks like there is only 1 of 2 half circle retaining rings for the big bearing on the secondary shaft. should there be 2?

the PO or the PO's PO, I suspect as to having messed with the motor, one of the side cover alignment dowels was a ground-down socket... eep?