Yet another XL600 project...

About a month ago someone made me an offer...

"You look like an idiot. Would you like to swap your nice 1980 XT250 for a dead 1984 Honda XL600R 'project' bike with unknown history."

I know, I know, that doesn't sound like much of a deal, but being a closet fan of big singles I committed the cardinal sin of trading my road-legal runner for a non-runner with the irresistible added attraction of 'some bits missing'.


Somewhere in there and a small box of bits is an XL600R. Honest!

And so that honeymoon period of garage time with a new bike project began. That time when you really get to know what you've bought into. Usually this consists of finding all sorts issues that you didn't spot when you actually inspected the thing. "How come I didn't spot the oil dripping out of drain plug because the thread's stripped ?", "Is that a 6" nail stuck in the front tyre?" that sort of thing. Well, so far it seems that karma has something slightly different in mind for me and the XL.


As I said, this XL is a totally unknown quantity. As I haven't heard it running, the first task is to get it fired-up before spending any money on it. Unusually, for this to happen, the engine has got to come out of the frame first! This is because karma obviously wasn't on the side of 'a previous owner', who at some point decided to cut a 6 inch section out of the frame tube, presumably to get around the problem of a seized top engine mount. There were tell-tale traces of engine oil everywhere; possibly because karma hadn't finished with our man yet, and didn't tip him off that the tube he was cutting held oil! ​

Ooops

The top engine mounts didn't come with the bike, so before welding a new piece of tube in I needed to know how and where these fit. A transatlantic message or two later and Advrider inmate, Brucifer, very kindly measured his XL frame giving me the measurements I required (he also had the idea of making a thread out of this rebuild - so if you're already bored, take it up with him!)

Happily, the rest of the bike doesn't seem so bad. The tyres are hardly worn. The wiring loom is in very good shape with just a couple of flag connectors to replace. Most of the fasteners are original and not chewed up, though two helicoils are needed on 6 mm stud holes in the cam cover. The first of the missing, but essential, parts - the bracket that holds the coil and CDI unit under the tank and the top engine mounts - have arrived from breakers in Germany and France via Ebay. I've selected some likely looking steel tube to repair the frame and my MIG welder is warmed up and ready.

So, everything is set, you're welcome to come along for the ride, but it might take a while...

im in!

Hey, HEY! Now were talkin'!

Awesome...a home made total loss lubrication system. IMO it would have worked better is the PO would have shoved (yes that's a mechanical term used in many shop manuals) a section of rubber hose over each end of the cut frame tube...removed one intake and one exhaust tappet cap and routed the hoses into the tappet cap holes letting the oil dump into the engine rather than lubricating the top of the rocker box. I give him an A for effort though, oil that recirculates ends up with contaminants from the combustion process,not to mention metal particles from the usual wear and tear of metal to metal part contact....brilliant I say. Oil tanks, sealed crankcases, and motor mounts are all over rated anyway.

Tech23

I'm considering my next move regarding the frame repair.

One thing I do know is that my current welding skills are not going to produce a good oil-tight job. Do I practice my welding until I'm 'good enough' or farm the job out to someone competent? Of course, I'm going to go down the practice-my-welding route. Anyway, the guy I got the bike from says he has a spare XR frame (of a similar year he says) that I can have. It'll probably turn out to be for something completely different and, for some reason, I'd like to keep the standard frame if possible. But I could use the XR frame to 'test' the engine while I improve my welding skills. The XR frame should arrive next weekend

In the meantime, to get in some garage time, I took the engine out of the frame and got it onto the work bench.



I was hoping that a brief look under the covers would suggest an engine strip wasn't necessary and, generally, it didn't look too bad inside. A brief peering, prodding and measuring session around the clutch, crank, cam-chain, cam bearings, etc and everything seemed OK. The oil residue was fairly clean (like new oil) and there were no metal fragments, flakes, grit or collections of grunge in the places where you might possibly expect to find such things.





I wanted a first look at the radial valve layout too so I lifted the rocker cover too. The cam and rockers all seem in reasonable shape (these are uncleaned parts, straight off the bike) with fairly minimal scoring or wear evident.



Silicone-gasket overkill on the clutch and generator cases. However, I've not recovered any bits of silicone from the oil filter or strainers.



Finding this is a bit worrying. The broken bit is the automatic decompresser cam thing that's operated by the kick-start, that's the kick-start needle bearing below it in the picture. So far I haven't found any chunks of it inside the engine so perhaps it's an 'old injury' that was never fixed? As a precaution I'll strip the oil pump to make sure it's clear of any debris and flush the engine out as best I can. I suppose I should strip the engine, split the cases and make sure there's no metal debris in there, but I'm tempted just to put it back together and take the chance. False economy?

In the meantime, back to the frame...

You're a brave soul...

+1

Probably more than I would take on (but it's not too hard to find a decent XL600r project around here).

I wish you best of luck!

I haven't done any looking but would a replacement frame be cheap enough to make fixing your current one not worth it?


And good to see you posting CW. Hope you didn't forget about me, I've logged in every day for the past year hoping to see a PM from you

You'll wanna fix that, they are a real pain to start without it. Make sure that you orient it properly before you re-install the cover, they can snap pretty easily if you tighten them down when oriented the wrong way. Make sure the spring on the cam chain adjuster is good. I've got the motor out of mine for the 3rd time before I figured it out.

Subscribed!

Yeah, I'm not so sure about that 250 to 600 swap based upon your description either
At least I now don't feel so bad about missing some items during my pre-purchase inspection of my 84 XR500

That frame should prove interesting to fix. If the other frame you get is from an 83-84 XR500, then I think there might be a better chance of the top engine mounts matching the XL6. But you will tell us all about it I'm sure

Another thought, did the frame get cut because someone wanted to remove the valve cover without removing the entire engine? That job can be done on newer XRs, but the XL6 and my XR5s don't have enough clearance between the cover and the frame member to remove the valve cover with the other engine mount bolts still attached. Although I agree that the seized mount is the more likely explanation. I may have a pair of upper engine mounts from an XL6 in my spares box. Let me know if that is something you would want, but I suppose you will make your own set to match your repairs.

You should double check that right side cam bearing. The shield/seal on one side of the bearing should be facing the right side next to the oil cup/chamber. That bearing looks to be installed backwards, or worse its the wrong bearing.

I updated my 84 oiling system to more modern components. Its a straight swap and I you can read about our discussions regarding the dry sump RFVC oiling system on this thread:

http://www.advrider.com/forums/showthread.php?t=552341

Thanks for the heads-up on that bearing, I would have missed that completely. Turns out it's the wrong one i.e. no shield. Typical! Presumably that means that at some point the camshaft might not have been properly charged with oil, etc. I'm going to have to replace that bearing with the correct type so as the cam's coming out I might as well take the head off too and clean up the valve faces and so on.

Any hints on removing the cam chain tensioner?

Interesting and useful stuff, thanks again

I wonder if that's what happened to it?

At the end of the first post in this thread I'd just come across this unorthodox engineering solution...



I also mentioned that the guy I got the bike from had offered me an XR frame he had as a spare. I was secretly hoping this might be a straight swap-in . Well, I'm not sure what year or even size XR the frame was but there was no chance of it being an easy swap, it was from a totally different era. However, I did spot a likely looking piece of tube with mount holes already welded in that I could repair my own frame with. In terms of welding, these 'cross tubes' were always going to be the hardest part of the job for me to get oil tight.



That's as close as you want to get to my shoddy welding! Even from this distance you can see why I was eager to save myself four more-awkward welds.

The mounting holes on the inset tube are 10mm closer together than the original XL head mounts so I'll have to make some new ones, but some progress has been made.



Back to the engine...

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

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 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.

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

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

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

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?

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/showpost.php?p=18632350&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