750/650 Frankenstein bike

ok I have a 82 750 maxim frame and engine. A 83 650 maxim harness. Everything seems to have gone together pretty well. Engine starts and runs, turn signals work along with brakes clutch and side stand switch. Can't get rid of the low oil level light. Is there a difference between the 650s switch and the one in the 750 engine?

 

I do believe that the 650 switch is electrically different from the 750 switch.
@chacal?

 

NOTE: when swapping engines (or oil pans/sensors) beware of these differences:

- the HCP700 (analog gauge) sensor is a N.C. (normally closed) style switch when the oil level is at a correct level, while the HCP701 (computer dash) sensor is a N.O. (normally open) switch when the oil level is at a correct level. Thus these sensors, If swapped between bikes, will not give proper signaling to their warning lights or read-outs!

HCP700 OEM new OIL LEVEL SENDING UNIT, for all XJ650 (except Turbo), all XJ700 except XS/XSC models, all 1983 XJ750 Maxim and Midnight Maxim, and all XJ900RK, RL, N/FN, F, and S/SH model engines.
$

HCP701 OEM new OIL LEVEL SENDING UNIT, for all XJ650 Turbo, all 1982 XJ750 Maxim and all XJ750 Seca engines.
$

 

THANK YOU. That is what it was acting like. I have the level switch from the 650 donner bike and have started the swap over. Any suggestions on a way to get to the wireing other than remove the engine ? That harness is between the frame rail and the oil pan in addition I think the connector is hidden behind the side stand mount. When I removed the switch from the doner bike I turned the bike upside down. Don't really want to do that to this one.

 

My only advice to getting to the harness is to do so carefully. You may find it easier if you remove the shift cover, and the mounting plate for the TCI.

 

Thanks. Exhaust is off and so is the shif cover and adjustable shift an foot rest along with the side stand switch. I'll try not to break anything.

 

You may not be aware, but the peg (foot rest) bolt is also an engine mounting bolt. It's fine to remove it, but don't go removing any of the other engine mounting bolts or you'll have a surprise.

 

Thanks for the heads up but not on this one. This 82 has the adjustable foot rests and shifter. It slides in a track and is mounted to the frame with one big bolt that act so as the pivot point for the slide. The rear motor mounts are to the inside of this mechanism and only attach the engine to the frame. Anyway the job was still a PITA. I ended up dropping the oil pan off just to get at the wireing. The sleeve on the pickup coils, neutral switch and oil level switch was very brittle from all the heat cycles. It broke off in chucks. I will have to find some way to protect the wires. The inside of the oil pan contained big chunks of plastic. I am guessing this is evadance of the primary chain guide breaking down. This engine does not make any funny noises or make me think there is an issue. What can I expect as the guide continues its slow death spiral ? I did clean out the oil pump pickup screen and got the sludge out of the pan.

 

Once the guide completely fails the chain will contact the oil nozzle that lubricates the chain and helps to cool the alternator via the alternator shaft. The oil nozzle takes a while to wear through, but all the while those little bits of steel will be in the oil (though they will get caught by the drain plug magnet eventually). The chain can also contact the case, but wearthrough is unlikely. Chunks of the guide can also prevent you from shifting. I'd do the job this winter.

 

That is a case split yes? Yep this winter sounds like a plan. Need to get this thing on the street and looking good by November. It going to be a wedding present for my new son in law

 

Yes. Case split. Rebuild the starter clutch at the same time. Use heat to help release the thread lock compound that is on the chian guide retaining bolts. Use Locktite 515 or 518 to reseal the case. The job can be done without disturbing the top end or removing the crankshaft. It's not a bad idea to use new crankshaft seals, but you can re-use the old ones if you are careful.

Does son-in-law like wrenching? You could make this your first bonding project.

 

This is a great idea. I actually tried to do the same thing with my father-in-law, but he wasn't having any of it. You could show him that digging into an engine isn't necessarily as scary as it sounds and maybe introduce him to a new hobby, if he isn't into that sort of thing already.

I'm in the middle of a starter clutch replacement myself and, while this site has some great members (like k-moe above) that can help out with anything you need on these bikes, nothing beats having someone there with you to help guide you through!

 

I asked him if he wanted to be part of the resurrection process and he does. So far he has been doing the chrome polishing and cleaning up of the pretty parts while I try and make this work and fit. They are moving back into the area in a couple of weeks so we will have plenty of "bonding" time real soon. Probably a good thing he wasn't there last night while I was working the oil level swap. I ended up damaging the pickup coil harness as the tubing was so brittle from all the thermal cycles. I'll have to get creative on the repair and protecting the wiring on a go forward basis.

 

I gave three of my sons 0n law custom painted bikes (one for a wedding present) only one of them still has the bike (the other two gave the bike back after a year ). I think they would appreciate it more it they had a hand in the restoration process.

 

Idiot lights.......
Just look at the oil level, then you know

 

I like to know when I'm riding too.

 

truth be told, i never had one
if it came on going down the road, wouldn't it be too late ?

 

It would not. The light comes on before the oil level is low enough to starve the oil pump. Not much before though. Even if you're totally out of oil the engine can run for a few minutes without damage.

 

My cousin was out riding on Sunday and some bolts must have backed out of his primary chain case and oil was all over his bike. I don't know if it leaked enough that it would have tripped the light if he had one or not, but it probably would have been nice to know asap when you start dumping oil. I probably wouldn't go out of my way to install a warning light on one that didn't have it, but if you have the functionality already it seems like a good idea to keep it. Seems like that could end up poorly if you went into the twisties with a bunch of oil on your rear tire.

 

Ok after taking a good look at the hunks of coal that were I the oil pan, and thinking about what this bike is going to do I decided to pull the engine and split the cases. The top end is in great shape so that part will stay together. A couple of questions. Are the chain guides available (OEM) or do I have to find a used part? Has anyone on this site done a DIY with pictures? If so can you point me to it? Here's what helped me arrive at this decision. So we are back to this state. All that's left is to disconnect the drive shaft and undo the motor mounts. Get this puppy on the bench and see what the gnomes inside look like.

 

Oh the brake parts came in. They fit great.

 

Chacal sells new chain guides. DO NOT replace it with a used guide. They fail from age, so you want a new one.

How to: http://xjbikes.com/forums/threads/xj750-engine-removal-and-split-pictures.38545/

But, get a factory service manual and a copy of the Haynes service manual. Neither one has all the information that you will need, so you really do need both. You will be better off having those books on-hand instead of waiting for answers from us as some steps are critical, and very well explained in the manuals.

I recommend Locktite 515 or 518 to re-seal the cases. It is so much more forgiving than other sealants.
Rebuild the starter clutch while you hae it apart.
Don't order parts until after you do the split and have inspected the lower end. Pay close attention to the condition of the oil nozzle, and its o-ring. Also be sure to clean, clean, clean to get all the plastic bits out (especially from the oil pump screen).

Also use some heat on the chain guide mounting bolts. They are held in with thead locking compound and are prone to snapping off during removal unless the compound is softened.

 

Chacal sells new ones - part HCP7551 OEM starter primary chain plastic GUIDE. I haven't found a complete walkthrough for the procedure, but I sort of started one based on the Haynes guide as I have been taking pictures while going through it myself; let me know if you want what I have so far. Before you remove the engine from the frame, I would suggest removing the alternator rotor and clutch hub. You can used the back brake to prevent things from turning, otherwise you will need to improvise a holding tool.

 

Oops, looks like k-moe beat me to it. And yes, the thread by cds1984 is excellent. Lots of good pictures, I wanted to make something a little more narrowly focused as you don't need to remove the top end for this job.

 

Thanks folks. I'll be asking questions as I go along. Time to get a conversation going with Len.

 

Ok the cases are split an parts are on the way. The process was not near as bad as I thought it would be so far thanks to the advice and threads here. The guide was basiclly non existent. There were mount points under the bolts but that was about it. Found pieces of it everywhere. The oil jet has some very minor scrape marks but is fully serviceable. I did follow the advice of drilling the peaned torx screws in the middle gear an became reacquainted with my 3/8s Impact driver. Haven't used that thing in 20 years but it saved my hide this time. All the gears look good and I borescoped the piston bores. 39K on this bike and they look very good.

 

did you take that steel plate off the oil pan? i found crap under there that needed a pressure washer to get out
also
http://www.xs11.com/forum/showthread.php?s=&threadid=5090
about half way down you'll see a guy with a dremmel tool on his gears, check yours out

 

Are you sure about this? The reason i wonder is i have a 750 seca and was swapping my gauge tonight, it turns out the sensor is closed with the correct level. Could it be different on européan bikes?

 

I did not disassemble the pan but now that I know to I will. There had to be parts of that guide everywhere cause while I was inspecting I found 2 big peices lodged insides the #3 piston. That must have happened when I set the engine upside down. The gears looked good and are of the newer back cut design so no issues there.

 

As far as I know the 650 sender is different. I have a 650 harness on this bike and the 750 sensor kept the light on all the time. Installed the 650 sensor and the light works a it should.

 

That's what i thought too, might have to change to a 650 sensor. What meters do you use?

 

I used the set from the donner 83 XJ 650.

 

As I was inspecting parts I noticed that the pin in the oil nozzle was missing. I'm not sure it was there when I removed it from the case. Can any one tell me what size the pin is suppose to be?

 

Just slightly larger than the pin hole (it's a roll pin) and no longe than the slot when installed. Chacal has just the pin if you can't find one at your local supplier.

 

OK time for the dumb question of the day. As my guide was totally destroyed and I cant really tell which side goes up, I've had it in there both ways, lumps toward the chain or smooth side toward the chain?

 

We're talking about the alternator chain guide, right? If so, smooth side toward chain (really, I think that goes for all of the guides). Should look like the attached picture, only not broken.

 

+1 there really isn't any other way to install it since the mounting tabs are angled.

 

SOME XJ650 senders are different.........the difference in senders is due to whether your bike has a "computer dash" to interpret the signal from the sender, or whether it has an analog "warning light" system. XJ650 Turbo models, since they have a "computer" dash, use the same sender as the XJ750J Maxim (1982 only!) and all 1981-83 XJ650 Seca (and XJ750 Euro) models. Note that the 1983 XJ750K Maxim went back to using "idiot lights" on the dash and thus reverted back to using the "idiot lights" sender...........

 

Ok that's the way it's in there but I'm telling you it will go in both ways. Thanks Gnat.

 

Hmm.. I guess I never tried to put it in any other way. I stand corrected.

 

During this process I have used zip lock bags for keeping assemblies together and I've tried to be very careful enough not to lose any parts in my overpacked garage. That being said I started the reassembly last night and I'm not sure if I have lost 3 bearing circlips or Ive lost my mind. Is there only 1 clip on 3 of the bearings and 2 on the bearing on the clutch side bearing? I've looked thru every bag and parts tray I have. The parts manuals call it out this way and my photos are not clear enough for me to tell. This is what happens when you spread a project like this out over a month and you have a bad case of CRS.

 

Just realized that I had never closed this thread out. The half ring bearing location clip question above was answered by study of the IPB. the cases went back together and the reassembly was no problem. As of today the bike has 150 miles on the repair with no issues. It was a fun sicence project that made me learn a lot about these bikes. Thanks to those who helped.

Dave