Splitting the Cases: To-Do List

Hello everyone, it's been a couple of years now so I got my '83 650 Maxim on the road, running smooth, and safe to operate thanks in no small part to the wealth of knowledge on this forum and chacal's fantastic service. That being said, there's just one niggle left that I'm now determined to fix over the next two months: unreliable warm-starts. That grinding, can of rocks has got to go, and since it's been in the single digits these days here in Maine I suppose there's no time like the present!

I believe I've exhausted all other easier remedies for the warm-start issue and it continues to be the one thing keeping me from feeling 100% confident in the bike's reliability, so it's time to do "the dirty deed": split the cases and rebuild the starter clutch. I have my Service and Haynes manuals handy, some helpful threads bookmarked (mainly XJ750 Engine removal and split - Pictures), and am ready to dig in.

So, I'm hoping to put together a to-do list for other things I should attend to while I'm in there (without digging much deeper into the engine than I need to for the starter clutch service), and I'm hoping those more wise and experienced than I can help me be prepared. My plan right now is to at the very least also replace the Primary Chain Guide while I'm in there, and also thoroughly inspect the frame while the engine's out.

My the Splitting the Cases To-Do List so far:

- Starter Clutch Rebuild, hub inspection
- Primary Chain Guide replacement, chain inspection
- Frame inspection

Any help in expanding on this will be greatly appreciated, thank you!

 

I'd add: transmission dogs and gears inspection

 

Splitting the case will expose the entire inner workings of the mill. The seals are 30+years old...replace them. Although the top end can be removed without separating each component it would be wise to lap the valves and add new stem seals. Read, re-read and ask when you're not for certain. It's not difficult, once you dive in, but several things MUST be re-assembled correctly for proper operation when the job is complete. We're here to help.

Gary H.

 

Beer.

 

I don't want to stop you going on your journey and know you said you tried the easy things. But I still can't keep my yapper shut.

I had the can of rocks things and the main culprit was an older battery, I also went through all of my electrical connections at the same time, cleaned, die-electriced and tightened them as well as re-furbed my starter. Rocks went away.

But hey, spring is still a ways off and there is good guidance here and why not have a project that can get you into the garage away from SWMBO for awhile?

 

Quebecois: thank you, I'll add that to the list!

K-moe: don't worry, I'll have that covered!

rocs: I'll admit that I was hoping to avoid working on that area mostly because I don't believe I've been shown any reason to think there's an issue there and also not wanting to take on too much at once. That being said, I recognize the wisdom in it!

The cylinder head will have to come off to split the cases anyway, so it'll all be right there in front of me anyway, right? The manuals make the idea of lapping the valves seem a little daunting with all the different widths and angles to the curvature of the valves' profiles, but maybe I'm over thinking it? With this forum and the proper homework I don't doubt I could do it, it's just more then I was hoping get away with this time around. But if it's the smart thing to do...

Stump lifter: your thoughts are definitely appreciated. I bought a new AGM battery which definitely made a noticeable difference, and have cleaned up a lot of the wiring at this point, including a new blade-style fuse box, new starter solenoid, rebuilt starter, replaced generator brushes, and cleaned up all the grounds. I'll admit that I haven't tackled the rat's nest behind the headlight though, or cleaned out the starter button switchgear, so maybe I haven't actually exhausted all other options.

 

Imo go ahead and clean up the bucket and controls; see if there's any change to how it starts. Splitting the case is a much higher degree of difficulty than lapping valves.

Gary H.

 

Locktite 515 or 518 for the case seal.

You can split the cases without touching the top end (you just can't pull the crankshaft out (well you can, but it's not a recommended method as the crank has to be turned by hand to get to all of the conrod bolts)). If all you're doing is replacing the alternator chain guide, rebuilding the starter clutch, and inspecting the transmission, the top end can be left alone. If top end trouble shows up later you can do all of that work with the engine in the frame.

The specs in the manual for the valves are for inspection purposes, and for re-cuting them if needed. Lapping is simply re-polishing them against the valve seat. This refreshes the seal, but can't be done if the valve is thin, burnt or pitted.

 

10-4 on the Loctite. I was over-thinking lapping the valves, and I am coming due for a re-check on their clearances anyway so it probably makes the most sense to do that now anyway.

Thanks again everyone, I'm sure I'll be back with more questions once I start getting my hands dirty!

 

Update: the more I've looked into splitting the cases, the more I've realized that if I'm going to do it I'm going to want to do more work then I was initially planning on in the interest of doing a thorough, one-and-done job, possibly going as far as a full frame-off restore. Since it's now February and I want it ready to go back on the road for March I've decided that for this year I'm going to just do the headlight bucket wiring clean-up combined with scheduled maintenance: it's due for a valve clearance check anyway and I'll follow that up with a couple rounds of vac. synching and ColorTuning.

I figure I'll see where that takes me, worst case scenario I'll just have to learn to be a proficient bump-starter. I'll enjoy the bike as-is for another year and then dive in deep late this fall, if I still feel the need at that time.

Thanks again for all your input!