I've been attempting to reinstall my newly cleaned carbs and so far have gotten 2 of the four air hoses back on. What I did according to one of the members here, worked by pushing the air hoses back into the box in order to remove the carbs out the left side. No Problem. Getting them back in is a real test of patience. Anyone out there have a technique? I managed to pull hoses forward but having a hard time coaxing them over the carbs. Is there some kind of "persuader" tool or will I need to remove battery & air box too? I'm so close to getting them on my 85 XJMAXIMX700, I love this bike! Had it for 6+ years (33K) Anyone? Help?


On my XJ650 there is a bolt on top of the airbox. I loosened the bolt and pushed the airbox as far back as it would go and re-tightened the bolt. This gave me another 3/4 inch to work with. I put the airbox to carb boots in place and then slid the carbs into the boots. Then I loosened the airbox again, left it loose and worried the carbs into the intake boots. Once I got the carbs into the intake boots I used a hammer to press the carbs into the intake boots while pushing the airbox toward the front of the bike. I tightened the little collars and voila! Tight seals all around with minimal effort.

They are called boots.
try a little bit of liquid dish soap on the inside lips of them. That's what i did.
Also, i'm sure you were smart enough to mark the boot orientation with a sharpy, both on the carb throat and boot, so you could make sure you lined them up exactly the same to go back on, right?
Reaching in the airbox and pushing from behind helps too, if your hands are small enough to fit.
Even if they pop out of the airbox, it's easier to get them on the carb and clamped, then worry about getting the far end back in the airbox correctly.

Picked up the grinder today, but had one blistering monster of a day with the kids and the relatives and the job. We'll see if there's any energy left for grinding on the 750 tomorrow.

Wow. Been a long time since I had time to work on the bikes, and no energy to do it. And it's 60 degrees here!

Finally got a chance to take the grinder to the oil filter bolt. Ground the head off and was able to pry off the filter cover.

Turns out that the only thing that was stuck was the head of the bolt, assisted by the very tight seal by that first O-ring. Once the head was ground off, it took a little effort to pry the cover off, and the rest of the bolt spun freely.

Ordered a spin-on filter conversion kit from chacal yesterday. Just waiting for that now and I can button it back up and run my compression test!

Though maybe I should try to get the middle gear drain plug ou...

Just kidding, Rick.

Ah, time in the garage again. I had bought a spare battery from a buddy of mine in hopes of using it on the 750. The terminals are reversed, but it makes a perfectly good test battery when used with jumper cables, so stuck that batt on the charger, then got to reassembling the oil filtration system.

Checked that the drain plug was secure, assembled the spin-on oil filter kit, and put just a little oil in her (about a quart) so I could see if the previous leaks it had were resolved and went inside.

Came out later to get some real work done. No leaks, so I filled her up with fresh 10W40. Still no leaks. Looking good.

Replaced the headlight bucket and headlight with one that is all in one piece.

Installed the new instrument cluster.

Pulled the plugs, unplugged the TCI, and hooked up the spare battery. Time for a compression test! Two years in the making! Results:

Cyl 1: 145
Cyl 2: 150
Cyl 3: 150
Cyl 4: 155

I was getting tired, so that last one might be a mis-read. I did have the throttle all the way open and let it crank over 5 or 6 times for each test. Tested each cylinder twice, with pretty consistent results. (I hope I didn't do any damage to the starter motor.) But some searching on this forum suggests that those are some pretty good numbers, so big win there! Glad I sprayed the cylinders with fogging oil a few months ago.

Noted that the guage cluster appears to work, though it's hard to tell for sure until the bike runs.

Then I started running into new challenges. First, I discovered that if you use the right tool - 3/8" drive hex socket set, instead of allen wrenches - you can get a lot further with the pinch bolts on the handlebars. However, even after removing those and the split pin and nut from the underside, I can't pull the clip-ons. What's the trick to getting that center bolt out? Is it supposed to just slip straight out, or does it have to be turned?

Another trick is that I bought a used right mirror, which threads in just fine, but the adjuster nut at the bottom doesn't appear to do anything. That thing IS supposed to move up and down on the mirror's shaft as you turn the nut, isn't it? Maybe I don't know how to mount mirrors.

After a very long and productive day (I didn't include the stuff I did to the 650), I called it quits.

FINALLY got the handlebars off. Apparently, banging on the bolts that hang beneath the upper steering clamp doesn't help, since they're not attached. The upper cap bolt is threaded and twists off. *sigh*

And, of course, the hex slot in it is not only far too small for a bolt with a head this big (bad design), but it's nearly rounded out and the sides of the bolt are a bit marred from my vice grips.

Been spending a bit more time on the 650, though, so work on the 750 has been slower than usual. I do have the replacement air filter and filter oil, which will get installed before too long. I really ought to pull apart the carbs before trying to fire the engine, though. They're probably full of gum.

Haven't had much time to dink with the 750 for a while, but she's coming up soon. I've put a lot of time and money into the 650 and THAT old girl is ready to go again!

Next for the 750 is to install the new air filter (in my possession), clean the carbs, clean the gas tank, and replace the fuel/vacuum hoses.

Then we'll see if she fires up! If she does, I'll go about restoring the rest of the bike. If not... well, it depends on why not. ;p

So I finally got some more time to play with this bike and have a couple of bits of good news.

First, I've mostly disassembled the carbs (aside from breaking apart the rack) and haven't found anything too horrible. They were a bit dirty, of course, but nothing some carb cleaner wouldn't get out. I'm a little worried about the enrichment wells, but a couple shots of compressed air seem to at least get fluid flowing through them. Not sure how (or even if) to clean the little nozzle that feeds the well, though.

Found one pilot fuel jet that was a 50, where the others are all 40s (stock). Also damaged one of the other pilot fuel jets getting them out, so that's two pilot fuel jets I'll have to get, plus four float bowl gaskets (just seems wise), and at least one diaphragm.

One of the 16 bolts that hold on the carb hats sheared off, and I did enough damage trying to drill it out that I think it's in there permanently. I don't think it's bad enough that things won't seal with a new diaphragm, but it's still annoying.

The other bit of good news is that with the carbs off, I put in new plugs, hooked everything up, sprayed a shot of starting fluid into each cylinder, and pushed the Start button.

Started. Right. Up.

For only one or two revolutions, of course. Did this test three times, and it ran perfectly three times. ^_^

It's looking like getting the carbs put back together and cleaning up the gas tank are the only major hurdles to getting this old girl running again!

I'm tempted to leave the rack in one piece, replace the funny fuel jets, and just put it back together and see what happens. The anti-tamper caps on the mixture screws are still in place, so with everything else stock and a decent bench sync, I ought to at least get it to fire up.

...in theory. I'm open to suggestions, though. Do I really need to break the carb rack apart and/or replace float needles and all that, or should I at least try it once as-is before going for the full-bore carb rebuild?

Well that's tuff to say.
To replace throttle shaft seals you need to break the rack.
It would suck to have cleaned them sterile only to have to pull them back off to replace the shaft seals.
The enrichment ciurcit hole in the bottom of the bowls should be so clean that carb cleaner shots across the room when sprayed through them.
If not they need to be cleaner.
People have boiled them in lemon juice and used guitar strings to clean them out proper.
Same for the "the little nozzle that feeds the well".

Quote::

I'm tempted to leave the rack in one piece, replace the funny fuel jets, and just put it back together and see what happens. The anti-tamper caps on the mixture screws are still in place, so with everything else stock and a decent bench sync, I ought to at least get it to fire up.

Don't take chances that it "might" be clean enough, Taking them on and off is a real pain in the #ss.