Scrap it or fix it - the crashed '83 XJ750MK

Bored on Craigslist, years ago, bought a 750 Maxim that had been in a wreck. I had heard they were good bikes. Took a gamble, and gave the seller his $400. Upon closer inspection, should have lowballed! Bike had not run since 2013 or so.

Seller was honest, told me what happened. Bike was running well enough to get it to the scene of the crash. But, boy, was it used and abused before the accident.

Bike sat in my garage for at least 3 years. Decided to see if it would run. It does! And idles. And revs. And goes into gear. And shifts thru the gears (all on the center stand).

Hot compression test as shown in the pictures. Makes electricity. Starter works. Turn signals work, what's left of them. Headlight works. Horn works, kinda. Engine sounds funny as one of the headers is GONE. How'd that happen?

No chance of corrosion, as the engine is coated in oil from top to bottom. For the rest of the bike, many Midnight Maxim only parts are crunched, though. Gas tank is salvageable.



I half expected to find a deal-breaker, and have the decision to scrap or fix evident for all to see. But, I don't know, I think there is a chance. If I adjust the valves, replace the valve cover gasket, rebuild the exhaust, maybe she'll come around. Thankfully the previous owner quit while he was ahead and only snapped off the two exhaust studs. I subscribe to the use-a-welder to get 'em out.

Ray

 

Welcome to the forum. that looks to be a good project bike that will need lots of love. If you have the time, go for it.

You will need to read a few of the links from the top right of any page. Take the time and read over the cost of one of these bikes. It will take some time to get the bike back on its feet so to speak but you will love working on it.

Please do a lot of reading and searching on this forum, so much information.

Those issues you have are not too bad and the compression test also looks not too bad.

Good luck on the project.

 

Thanks, Tim! Site is a treasure trove of information. And is the reason I dragged black ‘beauty’ out of the garage for a closer look. Valves will be first, although I’ve been tidying up wiring such that I could start the bike to listen for ugly noises. Even the oil change fought me. Stuck/rounded off oil filter cover bolt. But she’s got fresh Rotella T4 in there.

I’ve already got a replacement handlebar. Big challenge will be sourcing the muffler bits. eBay sellers want silly money to ship those size parts.

Steering head bearings need to be replaced. There’s a notch the size of the Grand Canyon about dead center. Fork seals are dry, amazingly enough.

Gauge cluster is trashed, and my be the hardest parts to find. Wish me luck! And thanks for the response.

 

Have you got these? Might help with your oil filter bolt removal. Harbor freight should have similar set.

https://www.sealantsandtoolsdirect.co.uk/damaged-rounded-bolt-nut-remover-10pc-socket-set-467893

 

Franz, that exactly what I needed to get the bolt out! Being cheap, I turned down the ruined bolt head and welded a nut on. Joy!

 

My previous owner went to the "don't fool with a new o-ring, just crank that oil filter bolt down as tight as you can, then another half-turn" school of thought.

 

Nice job.

 

Great repair.

 

Top choice: fix it.
Second choice: see if you can find somebody else who wants to take on the project and sell it for what you’ve got in to it.
Third choice: there are some good parts there that you could easily cover your cost


Nice repair though. For sure. Seems like you probably have the chops to make a quality repair in a reasonable time.

best of luck! Keep us updated

 

Thanks, Dan. I sorted out the wiring that mates to the battery, today. Next step will be to extract the broken exhaust studs on Cyl 2. They are broken off about a tenth of an inch below surface.

Ray

 

If you can fix up that filter bolt that nicely you can fix the rest of the bike. We have confidence in you and the staying power the XJ's.

 

@Ray Wilson
Looks like you have the skill and tools to do just about anything that might need to be done to the bike. Hope that your enjoy bring her back to life.

 

Thanks Tim, for my next trick, I’ll see if I can weld nuts on the sunken studs. Although, truth be told, if I have to pull the head, so be it. I don’t have to drive the bike to work next week.

 

Fix it!!! I rebuilt a Seca from an engine and frame bought for 100$ at a swap meet sold it on , recently bought another Seca for 100$ , got it running ,but still messing with wiring . I wrecked my beloved yellow Seca , but have put it back together . Here are pictures the Red bike was my swap meet 100$ special, old yellow, and my latest 100$ special.

 

@Jetfixer - was yellow a factory color? I dig the yellow.

 

The PO painted it that color , I like it as it matches my super beetle.

 

I like the Beetle Bug, too! I had one. Orange.

 

…and I need to start going to your swap-meet!

 

And so the valve clearance quest begins…. I bet these were never checked, adjusted, ever.

 

. I use a piece of Romex bent to a 90 degree angle .

















Be very careful using thus tool , you c an break the casting