New Member Post: 83 XJ750 Maxim

Hello my name is Dylan and I am new to this forum and motorcycles in general. I live in a suburb near Chicago.

I recently purchased a 1983 XJ750 Maxim as a project bike for the winter. It was running when I bought it but has been seriously negleted.
I plan on rebuilding the bike to make it safe to ride and turn it into a cafe/tracker/bobber.

So far I have determined I need to:

Rebuild carbs
Rebuild front forks
Service front/rear brakes
Change the engine oil/trans oil/shaft oil
Change air filter
Replace spark plugs
Replace fuse panel
Repair/replace gas tank (small leak)

I am sure I will have some questions throughout the process of this build so I figured I should introduce myself. I am excited to be a part of this community.

Here are some pictures:
Here is the bike the day I picked it up
And here I am with the fairings off

Here is how it sits now

 

Hi Dylan, welcome to the group. Add checking valve clearances to your list.

 

Thanks Stump,

I did see that mentioned when I was reading through the "Church of Clean" post on this forum.

 

Hey Dylan welcome. I'm sure someone will mention soon to add new brake lines to the list ! This is a great group of xjers

 

I was thinking of doing braided and maybe a new master cylinder when I do the front brakes. Thanks!

 

you can line the tank it would cost the same as having it silver soldered or welded and will not fail in another spot.
you can rebuild the MC it is a quick and easy job, same as rebuilding the calipers. bleedin the system can be a frustrating job ,there are a few threads on how to do the dual disc setup.

you can sell the faring and luggage boxes to finance your project put the round headlight back on

 

I may end up replacing the tank for a seca tank and the MC for the "look" I want. For the calipers do I need new dust seals or is there more required?

I have the fairing on craigslist now and I am planing on putting them up on here soon. Thank you for the advice!

 

there are 2 seals to be replaced

https://www.yamahapartsnation.com/oemparts/a/yam/50042394f8700209bc787ab4/front-brake-caliper

 

Don't forget to check the rear brake shoes. They are known to come apart with catastrophic results. Oops! The rear brake was already on the list!
Tires are stamped with an manufacturing date, if they're older than 6 years, replace!

 

I am going to try to take off the rear end tonight and see what shape the rear drum is in. I have a feeling it is toasted. I will put some pictures up and check the tires.

Thanks!

 

The rear wheel came off surprisingly easily and looks to be in good shape. I plan on cleaning it all up and replacing the shoes and greasing the spline. The brake pedal was not returning when it was pressed will replacing the shoes fix this? What all should I replace now that I have it apart?

I also checked the tire date code (0912) and it looks like I will need some new rubber soon.

 

I experienced the same issue with the pedal return. What I did was remove, clean, and grease the shaft that spreads the shoes, also where the small brake arm connects. I took it one step further with the removal, cleaning, and greasing the brake pedal shaft as well because mine was in dire need of it. After doing this, replacing the shoes, and cleaning everything up good the rear brakes work flawlessly

 

One other thing as far as the tires go, unless they look really good, no cracks, plenty of tread, etc, I'd replace them before you put it on the road. Not necessarily before you get all repairs, adjustments, etc done, but they are the only thing between you and the road. Peace of mind in my opinion

 

I would suggest taking pictures of everything so you see what it looks like old, and then new and then you have a reference to how to put it back together and a factory manual is #1 for that.

 

Brake pedal return - Mine was getting hung up on the muffler bracket. Simple bending solved the problem. I decided to keep my fairing but cut the windscreen down. Bar end mirrors attached to the body of the fairing. Rear fender and seat pan shortened 5" and 4", respectively. The original seat foam was cut down and re-upholstered. This bike sat in a shed for 12 years and the engine was locked up. Should have bought Naval Jelly by the quart and not the 8 oz. bottle!

 

Thank you for the advice, I will do that when the new shoes come in. As for the tires I plan I ordering a set before I ride.

I do have the factory manual and haynes manual. I can take after pictures also.

That's a nice looking bike! I will take a look at the return when I get it reassembled.
Is that exhaust stock?

 

No, definitely not a stock exhaust

 

Not the stock exhaust. It is a 4-into-1. No stamps or markings on it but it doesn't look like a MAC. Don't know what it is.

 

Does that require different sized jets in the carbs?

 

It would DEFINITELY require carbs...

 

You have a good starting point....a couple of caveats get bike running well and dependently before attempting any big mods. I do NOT recommend ripping out airbox and putting PODS on the argument that it makes it easier to remove carbs ...if your carbs are done right the first time you won't have to pull them back off. Check tire date even if the tread looks good if you can't find a date on tire if more than 5 years old better replace. Recommend upgrading to braided steel brake hoses ( xj4ever perfect fit and very high quality) expect to put between 3 to 6 hundred in parts but if you do it right you will have a good running and dependable bike . Good luck and keep us informed of progress.

 

I do plan on keeping the OEM airbox. I have read about all of the horror stories about pods so I will be avoiding them. I got the carbs out in about 20 minutes and they look in good shape. I just ordered a bunch of parts from Len over at XJ. The tires will be replaced, I haven't decided on a set yet. I also plan on getting steel braided lines.

I got bored this weekend and pulled some moreparts off. I will be cleaning and painting until all of my parts arrive.

 

I am running 43 idle jets and 120 mains. Seems to be too rich at start. I am considering going back to the stock 40 on the idle jets and 122 on the mains.

 

Then your idle would be leaner, but your mains would be richer yet.

Doood, your throttle-shaft seals are leaking! A LOT! See the dirty oily fuel staining on the linkage bosses?? Guess how it's got there....

 

I really like the way the single exhaust looks but I am not ready to start meddling around with these carbs.

I did notice that. I have the deluxe carb rebuild kit from XJ4ever so those seals will be replaced.

 

Ok, good

 

XJ750DB - When I got my bike it was running stock jets with the 4-1 exhaust, which was also stock (and quiet). I rebuilt the air filter with UNI foam and drilled a few holes in the muffler cap. That is the only reason I am changing jets. So a 4-1 exhaust doesn't necessarily mean you will have to change jets.

 

So I am working on rebuilding the front forks and I cannot remove the 19mm cap bolt to access the spring. Does anyone have any tips on how to get these off?
I also found why one fork was leaking oil like crazy, the washer the goes on top of the oil seal between the clip was missing. Also they used the wrong length bolt and stuffed washers on it and lots of locktite to make it work.

I was able to remove the air valve but I can't remove to 19mm bolt

Missing washer and wrong bolt

 

I just told Joe for you----
Push it down in , fighting against the spring, to expose the circlip for you to remove. Then the plug will come right out....careful-- the s print is strong and if you aren't careful it will shoot at you pretty good

 

Thanks Dave! I'll take a shot at it tomorrow and let you know how it goes.