Yet another XL600 project...

[Ghost_Mutant]

That frame repair looks great. Did you notice a cracked rear engine mount? I have three XR500 frames and interestingly enough all three had a cracked rear engine mount/tab in the same spot. I also had some small cracks were the seat and air filter box cross members meet the frame rails. I think the stress of getting too much air combined with the sharp angles caused the cracks. Newer XR frames look to have curved ends on those cross members which probably handles the stress better.

Originally Posted by JimRidesThis

Any hints on removing the cam chain tensioner?

I recall you just pull the pin on top that keeps the tensioner shaft from moving to the right, and then just grab the tab and pull it out while giving it a twisting motion. Once the shaft is out then tensioner can be removed from the top.

There is a pdf manual recently linked on The XL600 thread if you don't have one.

[JimRidesThis]

Originally Posted by brucifer

... Don't worry too much about your welds---the tank will cover them. Just giving you a bad time.

My thoughts exactly, there's no point in getting precious about something no one's going to see

[JimRidesThis]

Originally Posted by Ghost_Mutant

That frame repair looks great. Did you notice a cracked rear engine mount? I have three XR500 frames and interestingly enough all three had a cracked rear engine mount/tab in the same spot. I also had some small cracks were the seat and air filter box cross members meet the frame rails. I think the stress of getting too much air combined with the sharp angles caused the cracks. Newer XR frames look to have curved ends on those cross members which probably handles the stress better.

I hadn't noticed a cracked rear engine mount but I'll have a close look and let you know. I have checked the the 'flat' cross members and couldn't see any cracks in them though. I'll have a good check over the frame now it's repaired and stripped-out. The main thing for now is that it's oil tight

Originally Posted by Ghost_Mutant

I recall you just pull the pin on top that keeps the tensioner shaft from moving to the right, and then just grab the tab and pull it out while giving it a twisting motion. Once the shaft is out then tensioner can be removed from the top.

Yes that's what the Haynes manual says (got to say it really is a poor effort from Haynes). The pin is not a problem but the tensioner shaft doesn't seem to want want to come out (tried pulling it out with pliers). Are they a really tight fit? Should the tension be off the tensioner? If so, how do you do that? Mr Haynes is no help here

Originally Posted by Ghost_Mutant

There is a pdf manual recently linked on The XL600 thread if you don't have one.

I just found a link on page 229 of that thread but the resource file's obviously been removed. Does anyone have a copy please? Is it emailable?

[Ghost_Mutant]

Originally Posted by JimRidesThis

The pin is not a problem but the tensioner shaft doesn't seem to want want to come out (tried pulling it out with pliers). Are they a really tight fit? Should the tension be off the tensioner? If so, how do you do that? Mr Haynes is no help here

I'd call it a snug fit from what I remember. There is an O ring in there that seals up this shaft so oil does not leak out. Can you twist the shaft in one direction with the pliers? That should be easy to do after the retaining pin is removed. You might try vice grips to get a good hold, and then pull hard while turning the shaft. Should come out. If not, then perhaps the shaft has some deep wear marks in it that are getting hung up on the tensioner mechanism.

Look at this post for link (XL600R* (Inglese)):http://www.advrider.com/forums/showp...postcount=5709

[JimRidesThis]

Originally Posted by Ghost_Mutant

I'd call it a snug fit from what I remember. There is an O ring in there that seals up this shaft so oil does not leak out. Can you twist the shaft in one direction with the pliers? That should be easy to do after the retaining pin is removed. You might try vice grips to get a good hold, and then pull hard while turning the shaft. Should come out. If not, then perhaps the shaft has some deep wear marks in it that are getting hung up on the tensioner mechanism.

Look at this post for link (XL600R* (Inglese)):http://www.advrider.com/forums/showp...postcount=5709

Hey, cheers for the link. I've been able to download and print it all out today... at work

Had a little garage time this evening: there are no cracks in the mounts on the frame and the tensioner shaft, tensioner, cam and cam bearings are now out and all look OK. No pics, but you've seen all this stuff before

[JimRidesThis]

Progress on the XL has been slowed by some good riding weather Unfortunately, this has thrown up a small issue with my 1100GS - the clutch has started to slip As I'm riding down to Austria and Italy to indulge in some Alpine pass-bashing at the end of June, I suppose I'd better fix it before I go!

Anyway, the result is that the XL engine has remained well wrapped-up on the bench, but I haven't been entirely idle. Now that the frame's oil tight I can start the 'dry build' to check the state of the engine and find out exactly what's still missing from the rest of the bike.

The rear suspension and steering head bearings have been stripped, cleaned, inspected and re-greased. Everything checked out OK. So, now I have a moveable rolling chassis and I want to bolt on as much of the rest of the bike as possible. I only have a small garage space to work in, so I want to clear the decks for the GS clutch job.

In the meantime I'll order the engine parts I need - cam bearings, helicoil kit, gaskets, etc. - and put it all back together.

Here's where we stand today

[JimRidesThis]

Wake up at the back! Project XL is back on the bench...

I intended to just pop the engine back in the frame to see if it would run, but, when I started to clean out the clutch casing I started to come across some small chunks of debris, presumably from the broken decompressor cam. I don't want these getting into bearings, gears or oilways, so I'll to strip the engine, at least part way, to give me a chance to swill out any further bits and bobs that have found their way in there. With an engine this simple it's only a minor PITA :-)

I made a start this evening by removing the head and cylinder from the engine...




The head doesn't look in too bad a shape...


...and neither does the bore. No appreciable wear and no score marks that I can feel with my fingernail. The broken fins are NOT down to me!


I can't believe how big that piston is! I think Honda might have got a job lot from Leyland trucks or something

All these parts will be cleaned up, properly inspected and relevant tolerances measured. I've come across some small bits of debris or swarf in the timing side case so I'll remove the clutch to get better access for cleaning and strip the oil pump just in case.

More to follow...

[JimRidesThis]

Having revealed bits of the broken decompressor cam in the timing side case, karma decreed a partial engine strip might be a sensible idea. It'll allow me to swill out the cases with paraffin and check the crank and gearbox bearings for any free play or 'grittiness'.


It's what's missing here that I've found in the timing side case


Here's where we start from...




The following photos are really just my reference shots so I don't forget the order of parts, etc. :-)


The kickstart camplate and associated gubbins ready for inspection and cleaning


Holding the clutch centre without the correct tool could have proved tricky; but a strip of leather protecting the clutch centre, a pair of mole grips providing a positive stop against the outer drum and and extension bar on the socket did the trick


The crank nut with assorted pinions and the cam chain. I guess I it would be foolish not to replace the cam chain seeing as it's stripped down this far.


Almost a bare timing side case.

So, all in all it's not looking too bad so far. The clutch basket has some indentations from the clutch plates, but nothing that won't be cured with a few file strokes. The gearbox shafts turn very smoothly as does the crankshaft; there's no detectable wear in the bearings but these will be replaced anyway seeing as it's this far apart.

[brucifer]

Hey Jim! I would take your cylinder in to a machine shop and have them measure it. Just because it looks good doesn't mean it's in spec.
Maybe I'm just weird about things like this but I would replace all the bearings in your bottom end. The last two XR600s I built got all new bearings, new connecting rod, overbored piston etc. I guess I just feel since your in that far, might as well put new stuff in so you won't ever (hopefully) have to worry about anything going south.

The original engine from my '84 XL600 had about 22,000 miles on it when it lost a mainshaft bearing. Not real common but it happens. How many miles on your engine?

[JimRidesThis]

Originally Posted by brucifer

Hey Jim! I would take your cylinder in to a machine shop and have them measure it. Just because it looks good doesn't mean it's in spec.
Maybe I'm just weird about things like this but I would replace all the bearings in your bottom end. The last two XR600s I built got all new bearings, new connecting rod, overbored piston etc. I guess I just feel since your in that far, might as well put new stuff in so you won't ever (hopefully) have to worry about anything going south.

The original engine from my '84 XL600 had about 22,000 miles on it when it lost a mainshaft bearing. Not real common but it happens. How many miles on your engine?

That's sound advice Brucifer. I've got to say that even as I wrote my last post I was thinking 'oh yeah, as if you're going to stop now!'

I've got access to good measuring equipment at work so I can check the cylinder and piston there. I'll price up the bearings and I might as well factor in a full gasket set and seals too.

So the shopping list so far is...

Full gasket set
Oil seals
Bearings
Camchain
Decompressor cam and spring
Piston circlip
Crankshaft/clutch casing oil seal and circlip

Does anyone have a spare set of carbs-to-airbox rubber hoses, actually it's only the left hand one I need?

Are there any essential or worthwhile mods to do while I'm in this far? I did read something about an oil pump upgrade from an XR650 I think... from one of Ghost Mutant's posts in this thread.

[Ghost_Mutant]

The newer oil pumps have shaft seals internally. Those help prevent frame tank drain back when the engine is off.

But I think the bigger deal is the newer pump drive gear set. They run the pump a little bit faster for a given RPM.

You can run the new pump drive gears on the old pumps if you don't think you have a drain back problem.

I found the newer pump parts on ebay for my engine rebuilds.

[JimRidesThis]

Thanks GM. That's a great synopsis of the thread I had in mind. I don't know if it was wet-sumping or not, but I'll check out the availability and cost of the alternative pump parts anyway. I guess it's not that difficult to change it later, if the current pump has issues.

[JimRidesThis]

Needless to say I haven't got the "special tool" so...

do any of you gents know an alternative for removal of the flywheel? e.g. use rear wheel spindle as slide hammer, that sort of thing. I do own a set of 2/3 legged pullers (currently in hiding) but I don't think they're going to be the right tool for the job anyway.

Removed the kickstart shaft and took the piston off the conrod this evening and also cleaned up the clutch side casing threads, just in case any helicoils were needed - none were. Circlip added to the shopping list!

[Ghost_Mutant]

By special tool you mean the "bolt"?



http://www.motionpro.com/motorcycle/partno/08-0074/

M22X1.5 Right Hand threads.


To answer your question, no, I used the above motionpro bolt to remove my flywheels.

[JimRidesThis]

Originally Posted by Ghost_Mutant

By special tool you mean the "bolt"?



M22X1.5 Right Hand threads.

Thanks feller, I'll have to track down a 22mm x 1.5mm pitch bolt over here, it's good to have definite dimensions.


I'm afraid there's no real progress to report on my XL project. The crankcases are now separated but the flywheel is still attached. The main bearing I can see doesn't look too hot - the outer race is showing signs of pitting - so that just confirms that I'll replace all the bearings and seals suggested in a previous post.

Jim