SOFLA XJ 750 Project

Hi All....did a brief intro in the hangout lounge. Just purchased an 82 XJ 700 SECA for the princely sum of $300....PO wanted it gone. Now, I've been playing w/cars and bikes long enough to know you mostly get what you pay for so I got a complete, mostly stock bike that hadn't been running in maybe 6 months. Soooo, dead battery (PO gave me a new battery he purchased sometime in the past-dead of course-but a couple days on my battery tender and it's back to life). Now I don't actually want to start it yet but I did want to see the general state of the electrics.

So I installed the new battery, removed the 10 amp ignition fuse, and low and behold lights! Panel lights lit, brake light works on both the lever and pedal, blinker work...it's not all good. I surely haven't pored over the wiring diagram but the LED screen did nothing.

So far, so good....I installed the ignition fuse and with the petcock not petting any fuel....hit the starter button. This button doesn't depress as far as the starter on the FJR so at first when nothing happened I thought maybe a broken button....second time the starter kicked over strongly. All in all a good thing.

It's small progress but the electrics seem basically good. I don't much like the fuse holder the PO scabbed on the fuse box for the headlights-but that will be corrected with a fuse box upgrade anyway.

I still have a frozen lock cylinder in the fuel cap and a couple dozen other mechanical upgrades, little things like brake and hoses, before it's even close to rolling but it's good so far.

 

The polarizing layer on the LCD readout is most likely toast, which is why you don't see the readout. Get yourself some polarizing film sheet (or cheap polarizing sunglasses to test with first). You have a nice $300 pair of mufflers there, so you bought good.

 

This is why I join the forum....spot on, put on the glasses and there it is...seems like this should be a easy fix.

 

It is. Take care removing the housing to get to the display. There is an old thread about the procedure, but my Google-Fu seems to be lacking tonight.

 

For tonight's installment I stopped at the parts store to pick up a compression tester. Results seem acceptable for a bike with around 22K miles....145, 140, 135, 150....also got an ignition tester and confirmed good spark energy to all the plugs. Plugs were pretty black. I didn't bother checking the gap-I'll just replace with new. I'm still not ready to actually start the engine until I've had a chance to get into the fuel tank. I'm ordering up a couple key blanks so I can have a new key to work the gas cap lock with. Old key is cracked and I'm afraid it will break in the lock. I think while I'm waiting I will take the tank off so I can get a little better access to the front master cylinder, hoses, etc....

Opened up the airbox to check the filter...just a little oil film in the bottom from the crankcase vent...filter will of course be changed as will the oil and oil filter. The oil looks pretty good through the sight glass....still amber and does not appear discolored. But I want to be able to warm up the engine before I drain the old oil.

Tiny steps are better than no steps.

 

That rear frame looks alot like the xj1100's... hmmm... nice looking bike man!

 

did the po use the proper oil Jaso ma rated?
Choosing Oil for a Wet Clutch Motorcycle

wire diagram link if you need it


XJ750 RJ and RH (part1) *

XJ750 RJ and RH (part2) *

XJ650-750 component key (needed for files marked *)
from
http://xjdiagrams.thundervalleypower.com
there are other dia grams if this one does not work for you

those links do not work anymore st6opped a few hours after posting.
wiring diagrams can be found in the information over load

 

Don't have a lot of info on maintenance from PO....just that he occasionally changed the oil. I use Repsol synthetic in the FJR but I will probably just stick with Yamalube for the first oil change anyway.

Wiring diagram link will be helpful. I have the Haynes book so I'm not totally without information. So many things to do. Dismantled one of the front calipers yesterday...lots of pieces compared to the FJR and it has 4 pistons. What is normally done with all the anti-dive pieces on an overhaul? I'm reluctant to start pulling that stuff apart without good reason.

 

The anti-dive units are pretty simple, though they have some small parts that can't be replaced without making new ones (shot out to owners of 3D pronters). Typicaly the small piston that is actuated by the brake fluid will get stuck. Dissasembly and cleaning is all that the set on my 750 needed, along with new o-rings where the anti-dive unit mates to the fork leg.

 

Did a little garage rearranging tonight....the XJ now has a roommate...my FJR. I have an Ohlins rear shock to install there so they might as well move in together.

I have the front end now just about stripped down to the bare forks. Apparently I need to add a set of metric tubing wrenches to my already too large tool collection. I'm holding off on dismounting the master cylinder assembly till I have the right tool. No sense rounding off the fittings for no good reason. Fork tubes are toast. Seal contact area looks like it would be OK but the rest....needs RustEze bumper ointment....bad news. Are any other tubes interchangeable or is new the only way to go?

I have found one part I can clean up and reuse-the speedo drive unit. Needs to be cleaned up and lubed but the drive in the wheel hub looks brand new and the gears in the drive now turn nicely. Now I can't say the same for the headset bearings....toast...and the wheel bearings look like they're packed with dial soap...the yellow one...but they were on the list.

Onward and upward.

 

I've gotten a little sidetracked installing the Ohlins rear shock on the FJR. I'd forgotten what a b***h kitty it is to get to the rear shock and with the external reservoir...well, it was time for a rear swingarm service anyway...

However, I do have my first completed part. The speedo drive has been cleaned, painted, greased and reassembled. The first small victory.

 

Wish I had a roomy garage like that
Invest in a table lift, well worth the money and your back will thank you.
I've done several project bikes before and now couldn't do it without one. Or maybe I'm just getting old

 

Back from a little Seattle vacation...my fiance and I rode the Seattle duck boat tour just two days before the accident on the Aurora bridge. Very lucky.

I was struggling with getting the gas cap open so I had been wetting it down with PB Blaster. It soaked the week I was in Seattle and with a new key it I was able to wiggle it enough that it opened....what a mess:



Nasty. I was able to carefully disassemble it and it will need a "little" cleaning and few new parts but it came apart without any drama and should end up good as new. I'm not sure I can say the same for the tank. It was empty which probably explains why the engine cranks and spark but didn't even cough. Now that I have it off the bike it looks sound but some well-intentioned soul did a home tank lining with is not so sound. I guess it's "creem" or another product and I would guess the surface prep was poor because it's only partially adhering. So the tank is at the radiator shop to be cleaned up-I hope with some success. I really don't want to have to source a replacement. They're kind of expensive.

It looks like someone has "modified" the carb vacuum system sometime in the past. The vacuum line for the petcock ends attached to nothing. The individual vacuum lines for the carbs look to be cut off and sealed with BB's. I haven't done any research yet but I'm guessing this is where the vulnerable vacuum Tee's end up....



It looks a little naked now but it's a lot easier to get at every thing. I may have access to a lift table in another few weeks. I have a friend who's getting close to having his HD project back on the ground. Once he's finished the table's mine to use

 

Post up a pic of your forks for better diagnosis.
Your best bet is a set from the same model XJ, but Maxim 750 forks have the same upper tubes so you can mix/match if need be and still retain the anti-dive. XJ700 forks are also the same diameter.

There is only one vacuum line. It runs from the 3# intake manifold to the petcock. All the rest of the vacuum ports are blocked off during normal operation and are just there for carb synchronization.

That the petcock line is unattached to anything points to a petcock that has been modified to run without vacuum. It will need to be rebuilt.

If the inside of the fuel tank cleans up well enough you can line it with Caswells epoxy liner. RED KOTE and KREEM are both crap. The Caswells is essentially the same liner that is used on large underground fuel storage tanks.

 

Went back to the garage and took another look and sure enough...number 3 vacuum port was nekkid....





I slipped the vacuum hose on for the picture. I removed it from the petcock before lifting the tank so it must have been off already. I'm going to rebuild the petcock as a matter of routine. The vacuum side doesn't look too good-really grimy and "mossy".

 

The gas cap that used to look like this:



Now looks like this:



Thanks to a few part from Len at XJ4EVER and his very clear tutorial on how to overhaul your gas cap. Once the lock tumbler was cleaned up and the disks polished it worked like new. Now all I need is a cleaned gas tank....hmm, still at the rad shop....Hope he gets that finished tomorrow. I'm heading to Brazil on an extended business trip on Wednesday and would at least like to have it in the garage.

 

Wow....been forever since I posted. First it was a month in Brazil, then Curacao, then Bahamas (I know, it sounds sexy but but it's work and I'm pretty much over world travel)...then the holidays. So I was able to kind of pick things up. First things first....it runs! Put some gas in water bottle and fed the carbs....it started up and sounded pretty good. It jumped to 4500 rpm so I had to kill it-but it started up immediately after that, and after that so I ran it out of gas. That is somewhat of a relief since I bought it in a non-starting condition. I'll still check valve clearances and such but at least it does run.

I've started with the front end dismantling and stripped the front wheel in preparation for a refurb and new wheel bearings/seals.

The wheel is a little rough. Lots of oxide on the polished portion of the rim...the rest I guess is just really dirty


I tried to polish it with Flitz and it helped a little but the corrosion is clearly a bit deeper than just polish can handle
I'm going to get the old tire taken off and go after the rim to get all the grime off. For the bare aluminum I've used aluminum jelly in the past on engine intake manifolds but that was a cast finish. Anyone have any experience on polished wheels. I could also have them powder coated for $95 each locally but I'm not sold on the idea of all black wheels.

The fork tubes sure look like toast to me...at least the left side is.... The right side is a bit better, doesn't have the big scab on the upper portion of the tube. I do not believe these can be saved so it's either new tubes at $350 per pair new or a replacement front end of uncertain vintage. Guess I should decide before I get too deep into wheels, tires and brakes.

 

Out of town once again but off for MLK holiday so it was a bike day and it started out pretty well. Unpacked my new-used forks and they looked real good...till I rolled them over. One tube is pretty much mint the other...not so much. Fortunately the lower portion where the seal slides is very nice. The upper portion between the upper and lower tree has some rust. Not too-too bad and way better than what I have so it can work.




Once I got the headlight (I can't believe how many connectors end up inside that shell) and driving light out of the way I tackled the master cylinder. I'm not sure this is going to go back in as-is. I would sure like a late model lever with the reservoir on the bar for simplicity sake. I wiggled it out and when I got the boot off the bottom-oh no.



Now as bad as that looks I was able to remove the circlip from the master cylinder and the piston popped right out. Bore looked perfect. There was a little brake fluid still in there so I can go back stock if I want.

Like I said....good day till the end and a major "aw shit"! I pulled off the carbs and set them on the workbench and decided I'd remove the connectors from the engine and call it a day. Some of the cap screws were TIGHT....but I eased them off and all was good. Some came out with no problem. Till the last one. I tried PBBlaster, a little heat....I should have called it a day....I didn't and I now appear to be truly f****d...



That b***h snapped off....this has become way more complicated than I ever intended. At the very least the head is going to have to come off and go to a machine shop to have this drilled out and and insert installed....or maybe just another head. I open for suggestions. I guess this gives me plenty of time to rebuild all the other components. I need a drink.....

 

If you're not confident in drilling it out yourself, then definately take it to a machine shop. Take in a photo with dimensions; they might be willing to do the work with the engine in-situ.
I was able to drill one out by using a 90º attachment for my hand drill, but those cost about as much as wht a machine shop will charge to extract the remaining fastener.

 

I have drilled out more broken studs in exhaust manifolds than I care to remember....and a couple motor mount bolts in Honda cars. This does appear to be a little more delicate. My initial thought is to buy another head, rebuild it and install it. I'm assuming since the head studs hold both the head and cylinder block in place I need to replace gaskets for both. In my professional life I would never consider allowing someone to pull a cylinder head without changing all the liner seals at the same time-it would be an invitation to redo the job within days to deal with water jacket leaks.

 

Will an 83 head work? I'm negotiating on a parted out bike with a nice head-complete....Tks.

 

Yes a head from any year of XJ750 is a direct replacement. You'll need new gaskets, new o-rings for the YICS passages, and the special o-rings for the oil passages, along with the two special crush washers for the right side studs. Call a machine shop, you might find that it'll be less expensive for them to extract the broken bolt than the gaskets will cost.