1983 XJ650 Maxim bringing back to life

So,
Last motorcycle I owned was in the early 80's when I was 14.
Last motorcycle I rode was in the 90's in College (room mate had bike, I had car, many borrowing going on here).
Learner's permit (required in MD) scheduled but will attend rider safety course in the spring.

Friend purchased this 1983 Maxim 650 for $1K and I took it off his hands when he learned his son did not want the bike. I knew before going into this, I had a lot of work to do over this winter but that is the fun part. I've worked on small 2 cycle engines for large scale RC planes and did some engine work in HS and College on my cars so I"m no stranger to DIY repair. Looks like the owner friend purchased it from did not ride it much if at all. There are some things noticably buggered up and I"m sure he did not want to fix it. I'm told he just purchased another bike over a year ago. It already has new tires on it.

I'm not a mechanic but I am up to the challenge and if I don't have the tool, I'll buy it.
I am ordering some stuff from xj4ever for the carbs.

I have started on the Carb build but on initial assessment and many hours reading up on this bike I so far have my list in order of priority:
Carb Rebuild
New Plugs
Gas Tank rust remediation and sealing (its not too bad).Petcock Rebuild or replace (someone bypassed the vacuum line plugging it up)
Fuse box. One fuse holder snapped on me during inspection.
Both axles were missing cotter pins.
Rebuild front caliper/Brake system including new brake lines
Rear Pads

In between waiting for parts I'll clean it up too.

I have lots of questions to ask but will try to put in separate posts.

When first seeing the bike at my friends house, I noticed someone rebuilt the carbs and put the bowls on the wrong carbs so the drain screws are in the wrong direction. This gave me the thought to do a lot of inspection here.

 

Welcome to the party, @Melnic!!

Your story sounds a lot like mine - getting back into it later in life and ending up with a 650 Maxim in the garage!! I'm not saying I hope you end up with a garage full of XJs like me, but it's not the worst hobby somebody can have!

That's a pretty nice looking 650 Maxim. Should be more fun than a barrel of monkeys.

Sounds like you are well on your way.

I would add a couple things to "the list" that you may or may not want to consider looking at (just my $.02):
- Check/adjust valve clearances (do this before trying to sync carbs)
- Steering head bearings (how many miles are on the bike?) - easy upgrade that is worth the peace of mind
- Wheel bearings - again, easy to do while the wheels are off, its nice to know that they are new and in good condition
- If higher mileage, then maybe even swingarm bearings
- Maybe test the ignition coils just to make sure they are in spec

How bad is the rust in the tank? If it's not that bad maybe it's not worth risking damaging the paint to put a liner in (??)

Have fun!

 

Bike has 25K miles on it.
I know it had been serviced but can make no assumptions on what was done.
I'm going to try to get pics of the tank soon. Rust is spotty.

 

If I were you I would replace the steering head bearings at this point. It's no fun riding around with a "notch" in the steering. As long as you're doing all this work might as well.

The originals are ball bearings and in my opinion, 25k is enough. The replacements are an upgraded tapered roller bearing.

The steering head bearings don't require any special tools or pullers or anything to get the old ones out - just kind of a big old flat screwdriver to use as a drift. Once you get the old races out you can use them as a tool to tap the new races into place.

Then you will be able to experience the joy of nice smooth steering and finding ball bearings around the garage floor for years to come.

 

Welcome to the forum. Looks like you do have a nice project bike there. In good shape and well worth the time. Take your time on them carbs, as you mentioned you have done a lot of reading. I do hope that the "Church of clean" was on that reading list? You will have to do a really good job of cleaning them carbs.

Sounds like you know the safety issues should be taken care of first to make it road worthy. As for the tank....depending how bad it is I would not seal it either. I have done many tanks sense starting to play with older metric bikes. Depending how bad they are depends on what I do to or with them.

Evapo Rust even thought cost $20+ per gal, is a really good product. Just needs to sit in the tank at room temp to work. Can't have it in cold or freezing area it will not work so well. If you just have some small rust patches then it should be easy to take care of.

I would recommend a inline filter after the tank cleaning. All the work you will put into the carbs can be reversed with bad gas and bits from the tank really quickly.

Keep motivated and just take your time. Winter is here and in out area so enjoy the winter project. Lots of pics when you start to get in there.

 

it looks like you have 2 wrong float bowls on there, as you say 2 should point one way and 2 the other way, i dont think the bowls can be turned round, otherwise they would be pointing towards the engine

 

Number 4 needs to be swapped with number 2. All fixed!

 

Can I put the inline filter right at the output of the petcock and just run a longer fuel line down to the Carb 1&2 Tee?
Any issue with filter running horizontally?


Rotors, These look like a 1980 Led Zeppelin vinyl record, Do I buy the ebay rotors that are slotted or can these be turned or something else? I have time cause I'm not buying anything yet that does not have to do with getting the engine running.

I did not read the church of clean post, but am reading it now.
I pulled one carb apart to start with leaving the other 3 together. There are slight differences in the machining that I am aware of and marked the carb bodies. I had already been taking LOTS of pictures.

 

but they would still all be facing the same way

 

The outputs (drain holes) will always face to the rear. The screws need to face the outside of the bike. #1 and #2 to the left side and #3 and #4 to the right side. Swapping the two bowls will do that.

 

Yes, I know what I need to do for the bowls.

 

nope, still dont see that,
1 2 3 4
/ / / /

his screws are all pointing the same way, swopping 2 with 4 they will still face the same way

 

His #1 and #4 screws face left and #2 and #3 face right. Look close.
1 2 3 4
/ \ \ /
Swap #2 and #4 and all is good.

 

Huntchunks has it correct.

BTW, took apart Carb 3, The boss /peg for supporting the float pin/axle was bent up and I barely touched it and it snapped off. Will JBweld it and I cut a groove, to put in some reinforcemnet.
I already measured the spacing in order to put the bowl cover back on so I know how much room I have.

Carb #2 and Carb #1 did not have the screens installed under the Brass fitting where the bowl fuel shut off Peg goes down.
Carb #3 did not have the washer for the Idle mixture set screw that goes between the spring and the O ring there.

All 4 carbs, the idle mixture screws were between fully closed and 1/4 turn open. I don't get how this could have idled reliably.

 

Forgot pics.
I did not feel comfortable drilling in and putting in pins and getting the alignment right so I'm taking a long 2mm screw and cutting head off then adding it as a JB welded splint.
Cleaned the body and degreased in prep for JBweld. Purchased a new set of tubes today and will mix up a test batch to verify it hardens. years ago, I used a mix that was old and did not like it as it hardened so pre testing the batch is a good idea for something like this where messing it up can be costly.

 

Looks like the well in the casting at the inside of each pillar could be a place to anchor a support up the inside surface of the pillar.

 

Yea, I think I may put a splint on that side but not dig a channel. Good suggestion. I need to look at the float and the interaction the next time I'm working on it.

 

A link to a repair I did, which also contains some repairs from other folks. I was hesitant to drill for the pins also, but it worked well after I flatted the broken area with a file and center punched.

https://xjbikes.com/forums/threads/broke-carb-now-repair-replace.130735/

 

This might work. Assuming the drilling could be done accurately which is critical I wonder if a roll pin would work to bridge and strengthen the joint plus using quicksteel putty or a suitable alternative. The roll pin would need to grip enough without being too tight in case it burst the post.

 

Car JB weld done (need to get a pic) .
While pulling 2 of the carbs apart, I had to use an easy out to get 2 of the air jets out, so ordered some from xj4ever. In the process found that whomever did a rebuild on this, tweeked the jets and put in bigger main fuel jets (130 instead of 110 Main and 45 instead of 40 pilot). The air jets were sized like an older carb and a day after ordering the air jets, read up on the thread size of the air jets being different on the older carbs. I'll find out and compare when the new jets come in. I do have enough parts to put the rack together and put the jets in after I'm done. I could also set the float bowl levels if I wanted to on the bench and put jets in later as I believe Jets missing wont affect that. (I can put the original fuel jets in to hold the emulsifier (?) tube in till the jets come in.

I put in a blade fuse block and noticed that the cover is rather tall. I feel it pushes on the bottom of the seat and don't like the idea that so I 3D printed a slightly lower profile cover. The original main fuse was hanging on a thread and my buddy who sold me the bike said the tail lights were intermittent (he bought it 2 weeks ago himself as a project and turned it over to me for the $ he had in it).
Next I'll make labels for it. In another thread, I learned to jump out the headlight relay w/o starting the battery so the main electrical seems operational.