Yet another XL600 project...

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 :huh 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

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...

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.

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.

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.

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.

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!

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.

Thanks! 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

These images are from the Honda workshop manual here... http://www.hondaxl.it/manuali.htm (Section 10)



There's a specific reference to a bearing plate in right-hand side crankcase 'behind' the main bearing. My XL doesn't have one and there doesn't seem to be one in the other photos in the manual (you can see the bearing cage, not a plate)...



So, what's the story with this bearing plate? Has your XL got one? Should my XL ('85 model) have one?

Your wrong. The plate goes on the LEFT side of the crank between the bearing and the case. What it does id shield the bearing and keeps oil in the crank area. Never seen a Honda big single without one.

My earlier post should have said my XL didn't have one. Now corrected.

Steve, thanks for clarifying that and so quick too. You've gotta love this forum.

Of course, I can see that you're right from the photos (i.e. it's a left-hand side crankcase in the picture), but the text is unambiguous (and then confused).

"Install the new right crankshaft bearing and bearing plate"

"Install new left crankshaft bearing into the right crankcase" (that one I was going to ignore I think the technical writer must've been stoned that day)



...plus I still haven't removed the rotor or crank from the left side crankcase yet so I can't get a good look at the left main bearing.


Thanks again. I'll stop worrying about it now

Carry on. Next....

Keep it up and you'll end up with a cool big ol' thumper, gobs of torque.

I bought my 83 XL600 as a $200 chassis/basket case, complete but only the crankcase in the frame. Kid I bought it from said he tore it down because of a bent valve, and then quit the project. Good enough challenge for me!

I replaced the bent valve, freshened up the cylinder, new rings, bolted it all back together and it fired on the 5th kick, no decomp lever. I had a cheapo running thumper for less than $300. Did some trail riding and got some dirt on it. But, when climbing a hill in 2nd gear, I found my error in using the original cam chain. See, I thought the cam chain installed real easy, but simply went ahead with it. Yup, worn cam chain skipped teeth under load and the piston wacked the intake valves. Bent them both.

So I torn it down, replaced the cam chain, chain guides, intake valves, few other parts. Again, bolted up, and it fired again after a few kicks. Been good ever since, just a bugger to start sometimes as it is a big single. I need to get the decomp lever/cam working again. Since I have since bought a 2004 DRZ400E (electric start) my plan is to turn the XL600 into a retro-motard/street-tracker.

I still like the bike. But if I were you I'd replace the cam chain and guides before putting it back together. One thing about the big ol Honda singles is they tend to use up cam chains.

Thanks Andy. A cam chain and guides are on the shopping list


Meanwhile, back at the ranch...

...the tear down continues.


This is roughly where I'd got to; 'cases still together but ready to split, rotor still attached.





From there it was easy enough to split the 'cases...




Hmmn, Hermatite Orange

...pull out some bearings, clean the cases up a little...





...and start ordering new bearings and seals.


Gearbox bearings and seal, clutch side


Mainshaft bearing and seal

For UK info, the bearings and seals came from Simply Bearings in Leigh (do a Google search). These were ordered using their online service but didn't list the right sizes for the main and balance shaft bearings, I'll give 'em a call.

The main and balancer bearings may be Honda specific.

Has that been apart before? Was there no center case gasket? It looks like high temp red silicone sealant on the center cases. I wonder why anyone would risk using that stuff. Hondabond HT is great stuff, it works well enough for Honda at the factory, but I thought they only applied it to the cam cover. I don't apply it in a bead then slap the cases together...that just leaves those big globs behind like in the pictures. I apply a thin bead as uniform as possible then go back and dab my index finger on the bead all the way around the case so there is a nice uniform "textured" appearance to the sealant when I'm done. When you put the cases together you get a nice thin amount of sealant squishing out like it comes from the factory...no blobs squishing inside or outside the cases. Excess sealant inside the case can break loose and get into oil passages and starve the internals of oil flow...gotta be careful with sealant..

Tech23

I reckon so Steve. The main bearings are still listed as available but the balance-shaft bearings aren't. I'll find 'em though

You're absolutely right Tech23, your method is exactly how I would apply silicone sealant too - I would also allow the flattened 'bead' of gasket goo to go off slightly; used to work a treat on my old Thunderbird's primary chain cases . Apparently the previous builder didn't know any of that and didn't use a 'paper' gasket.

This was the clutch cover. He'd obviously used a tube of the orange stuff on the crankcases and only had black stuff left!



A full gasket set was delivered today!