High mileage stuff

I just got back from the machine shop!




Last week I had the cylinder head, cams, valves, and other top-end stuff taken to a local machine shop for a good cleaning and inspection (shout-out to Stradley's Machine Shop in Titusville). And now it's back!

I'm really satisfied with the cleaning. I also had them lap the valves while they were at it, so the valves should be really happy now. The mechanic said that everything looked good for its age, so that's good to hear as well.

I'm still trying to get that pesky stud/dowel pin out from the cylinder jugs, but once that's done, I can begin replacing the rusted studs and begin putting this whole thing back together.

 

Looks awesome. Keep us updated.

 

I finally removed some studs.

I ended up pulling upwards on the corroded stud while twisting it with a wrench, causing it to thread its way through the remaining corrosion.


(click for a larger view)

There's still a few more to go, however, and they're not the clean ones. Since all the rusted/corroded studs are on the front row, I am going to go ahead and replace just that row of studs.

Here's the problem: the service manual doesn't say anything about the studs. No installation/removal procedures, no specs for inspection, and no torque values (nothing that I could find, anyway).

Does anyone have any tips for installing new studs, like general torque specs, or if I should use thread-locking compound, etc?

Edit: Got them all out. The rest were much easier than the one I mentioned earlier. Time to order some parts and start cleaning this mess.

 

I've begun cleaning the surface of the cylinder jugs and I'm now worried that I've damaged it.


(click the thumbnails for full view, I didn't re-size them to preserve detail)

I've used sponges, plastic scrapers (which didn't phase the gasket residue), razor blades (which did), 80 grit sand paper (also worked, better than the razor), and gasket remover foam.

After searching the web I've found a lot of contradictory advice. I'm now worried that the razor blade and sand paper have damaged the surface of the engine. As seen in the pictures, there are lots of little scratches everywhere, but they are difficult to feel, ie they aren't very deep. Placing the razor blade edge against the surface where I used the sand paper doesn't seem to reveal any visible warpage. Maybe I'm worrying too much?

In any case, does anyone have any advice on how to clean this surface?

 

I don't use sand paper on any engine because the grit or abrasive can get into places you don't want it to. Just razor blade it clean and you will be fine. Blow every thing off good to get rid of as much grit as you can

 

that cylinder looks fine and looks clean enough already.
are the valves marked? once a valve is lapped into it's seat it should stay with that hole

 

If that was my head I'd have it milled, man that is rough.

 

I'm with The Wiz on this, with all the work you're doing, just bite the bullet and have the head gasket mating surfaces milled to ensure absolute flatness and clean-up anyd surface blemishes. Have the cylinder bores checked for size, roundness, and taper, and correct if needed. Have pistons checked, too.

Yes, you'll probably spend another $200 doing all that but that's less than $20/month for the next year, or slightly less than a couple of Micky D meals.........

Motor will scream once you're done! How's that starter clutch and hy-vo chain guide looking?

 

i'd like to see a better picture of those cams. how deep are those scratches?
do you have any way to measure the lobes?

 

You guys are starting to scare me now!

I changed my mind on pulling the cylinders because I was worried about needing new pistons. Oversize pistons for this bike are virtually impossible to find, and very expensive if you do. $200 isn't far at all from what I expected to spend to finish this project, but if those engine parts need replacing I'll be paying MUCH more than that, which is really my main concern.

But I suppose that's what I signed up for when I began all this work. I guess it's in my interest to go a little deeper, as I certainly don't want to do this again. If I take the cylinders off and take this stuff in to the machine shop, how's this for a worklist?

- Check piston diameter, cylinder bore/roundness/taper.
- At a minimum, install new piston rings and have the cylinders honed. I guess the wear of all the parts will determine if I have to use oversize parts, but if I do, I'm really in trouble. I've found some aftermarket standard sized piston rings for a curiously low price (anyone have any experiences with aftermarket rings?), but again, anything else = $$$.
- Clean the pistons (if re-usable), cylinders, and mill the top of the cylinder jugs. I had the cylinder head cleaned, does that need any more work?
- I might as well just haul the bike down to the shop and have them clean the base gasket mating surfaces as well, as I'm not so great with the whole cleaning thing.

(click for a larger view)

The cam lobe is pretty shiny so it's hard to get a good picture that shows the scratches, as any light reflection hides the scratches. They aren't very deep, I can feel them with my fingernail but that's it. For what it's worth, the guy at the machine shop said he'd re-use it, but if you guys really recommend it, I guess I could find a replacement. Last time I checked ebay used replacement cams can be had for a decent price.

Bottom-end already? Too soon man, too soon...

 

Bottom-end already? Too soon man, too soon...

Never too soon to replace that starter clutch, et al.

 

the lobe of the cam and the valve shim rely on a layer of oil to keep them apart while the valve gets pushed down. the oil doesn't get squashed out because there is no where for it to go, the shim is smooth and the cam is smooth and the oil can't move that far that fast.
yours has groves to let the oil squish into. the lobe starts touching the shim and bad things start to happen

 

I know, I just want to finish the top-end before I get started on another major task. I was having starter clutch issues before all this, but I was running full-synthetic oil in it, so I was hoping that I could buy some time by switching to a conventional oil.

So I should replace the cam? What I really want to know is how this happened. I never used any magnetized tools to adjust the valves or anything, so I don't think that could be the cause of the wear. How long does a camshaft last anyway? It probably depends on too many factors.

Any more advice concerning my piston issue? Or is there really no telling until I get it all into a shop and measured?

 

replace the cam? i would.
before you get into pistons, rings and bore and hone, you should step back and do one of those cost benefit things.

 

I removed the cylinders:





Time to take this stuff into the machine shop.

There was a lot of crud that fell into the engine. Not much I can do in the way of cleaning it, not without splitting the cases I guess. Which I'll probably have to do anyway because I dropped one of the piston pin clips into the crankcase, as well as discovered a noticeable crack in the primary chain guide.




If I wasn't way in over my head before, I certainly am now . Perhaps I miscalculated the cost/benefit.

 

Drop the pan & flush it through.

 

It's been a while, but this holiday weekend has given me a little bit of time to work on the bike.

I'm going to have to replace the primary chain guide, starter clutch parts, and other internal bits, so I'm getting ready to pull the engine. I disconnected many wires and removed the airbox and such. All I have to do is disconnect the drive shaft and the actual engine mounting bolts. Once it's out I can clean and inspect the frame.

Is there anything else I should do before removing the engine? Maybe take apart the clutch, alternator, etc? Any more tips for taking this beast apart?

 

take all that stuff off first, save the clutch for last. any bolt you turn is going to try to spin the engine and you use the trans and wheel to hold it back, plus it gets a lot lighter to pick up.
the u-joint flange is a pinch point for your fingers and that rubber cover, be careful there. last time i did one i unbolted the swingarm and wedged it back a little, much better.

 

slj64,

What you're doing with your bike is very impressive and quite encouraging. It takes some real "gonads" and or "t@ts" (for the ladies ) to go that deep into a rebuild w/o having someone(s) literally standing there giving you instructions. That is some of what makes this forum so dag gom great. A person can take a good platform non-running XJ and make that bike purr like a kitten, and keep it purring for as long as they chose to do so. And even tho I understand some of why these bikes don't have the market value that many of us think they should have, the knowledge and expertise you'll have once you put your bike together will be invaluable. So, cudos to you.

Gary

 

Hey guys, just stopping by to say I'm not dead! I've made some progress:



The clutch, alternator, shifter, and timing stuff is all disassembled. There are only a few parts left to remove before it's time to split the cases.

How hard is it to split/seal the cases, anyway? To be honest, this is the part that I am most worried about. That and gluing it back together.

I know you guys generally frown upon taking these bikes to a shop, but I've considered doing this just to have the primary chain+guide and starter clutch stuff replaced. I haven't talked to any local shops about this though, so I'm not sure they would even do it. I ordered some case sealant so I have the stuff to do it myself, I just really don't want to do this again.

I'm going to take the cylinder head in to a shop be reassembled soon, so maybe I'll talk to them about it. In the mean time, any advice on where to go from here?