1983 GS750E Rebuild

[Guest]

Welp. It's definitely been a bit since I posted. Nice weather is finally here in the PNW and I'm making good progress. I have been sidetracked by school (Mechanical Engineering) and work, as well as the wet weather, but getting back to work on this.
Got the frame and triple tree (and some other parts) back from powder coating and have the engine painted and rebuilt. Going to get it back in the frame once I have the valves adjusted and fins polished. I'll post pictures tomorrow. Have taken the time to do research and make some informed decisions regarding this build while I wasn't working on the bike. Decided to build a new electrical harness, and use a Motogadget M.Unit Blue to make the system simpler and more advanced. Hoping the old igniter unit is still good, but if it turns out not to be will replace with a system from Boyer Brandsen. Hardest part right now is just balancing time to work on it and waiting of parts/being able to order parts.

Cheers

[MaurieG]

Your rear master cyl. Remove the nozzle off a std. grease gun, and pump the piston out. Messy ... but never fails!

[Guest]

Man, I've done a bad job at keeping this thread going. Luckily, I've been better about the bike. Made great progress, just waiting for school and work to die down to really get through the final stretch.

MaurieG, thanks for the advice. I gave that a shot and unfortunately it didn't work. I'm afraid the bore is simply too pitted to really save, as well. That's okay though. I'm going to try using an after market 14mm Master for the rear, just need to measure and CAD up a bracket to mount it, and have a machinist friend make it for me. Actually have a few brackets to make. Rear master, gauge cluster, speed sensor/hall sensor, and a tray to hold electronics.

Here's pictures leading up to the most recent.

https://photos.app.goo.gl/DTdXrrQ4k5cm5eFA9

I unfortunately am posting this from work (Shhhh, no one needs to know), so I can't post the pictures directly, but can later if need be.

I ended up getting a late 90s/ early 2000s Ducati M900 shock and using that plus the original spring for my rear suspension. Old shock was unfortunately in bad shape when I got it apart to check everything. Maybe I'll upgrade to a Hagon in a year or two, hah.

Waiting on the tins and tank to get back from paint. Actually decided to "convert" the bike to an ES model, a I can no longer find the original E fairing/cowling. I do like the ES look immensely, so it's fine by me. Going to go with the original white with red decals.

At the moment the latest thing I've done, which has made me question my work so far, is test the started motor (works great, have a new brush kit just in case) and checked compression. I understand compression will be low after a top end rebuild, especially with a new hone and rings, but I'm getting 35 PSI across the board (with or without oil squirted in cylinders). I feel like that's too low, so I'm going to double check my valve clearances. I did my best to follow the factory manual, but it isn't the best written, and the main photo for it seems to be labeled incorrectly. Once I re-adjust valves, I'll re-check compression and see if that makes a difference. I did notice a little tiny bit of oil seepage on the gasket between head and jugs, at the very front (there's a projection on the front in the middle that has a single bolt connecting jugs to head) so keeping my eye on that. Also getting leakage from the clutch/shift rod seal, so will replace that. In my experience and by looking at the seal, it can be simply pulled out and pressed in, atleast I hope.

Hopefully will keep making progress!

[Guest]

Actually wondering if I should try a different compression gauge...