Ted's '82 XJ750 Maxim Bobber

Re: Bringing a '82 XJ750 Maxim back to life-might need some

Yes, you can set the fuel levels without the mixture screws.

As far as the linkages binding you said you didn't split the rack, is this correct? Did you dip the carbs? They look really clean. If so you probably damages the shaft seals. I don't exactly know what the dip does to the seals but perhaps they get gummy and sticky? Anyway I would now say to split the rack and replace the seals. You don't want the thing staying open.

When you re-install the butterflies go easy on the lock-tight. I found out the hard way that too much on the screws and it will find it's way onto the shafts and set up in the bores. Then you get to split it again and clean the excess lock-tight.

 

Re: Bringing a '82 XJ750 Maxim back to life-might need some

Yeah, sorry, I should have clarified.. I did not split the rack or dip it. I just sprayed it out really good with carb cleaner, then air, then carb cleaner, then more air, etc.. GD I really don't want to split these puppies but I'm afraid you're right about the seals getting gummy...

I soaked all of the smaller metal parts in the carb dip for about 45 minutes then scrubbed, rinsed, and air-dried.

EDIT: went back out & hosed down all the linkage with a little carb cleaner, then some more lube & it worked loose. Seems OK now but I have a feeling it might be locked up again in the morning if those seals are hosed. There is a slight hesitation when it closes.. should it really "snap" shut (like the clunk test) or is there normally some spring tension hesitation there?

Special thanks to Biggs for the advice so far!

 

Re: Bringing a '82 XJ750 Maxim back to life-might need some

All good things here, fellas! Carbs are together (except for air mix screws - waiting on o-rings from chacal) & I set all float heights to 17.5 mm. I'm going to get a fuel filter before I do a final fuel level check (especially important since I tossed the little dome filters on the seats - one was shot and the new seats didn't come with replacements). - thanks for the links Biggs500 they were suuuper helpful!

Also... all valve clearances are within spec! Can't tell you all how relieved I am about that. Just one less thing to worry about!

Headed back out to the garage now... gonna' try to force myself to pull the real wheel and check those brakes for delamination but I might just drink beer, listen to rock 'n' roll and stare at the bike for awhile :lol:

Cheers!!

 

Re: Bringing a '82 XJ750 Maxim back to life-might need some

IT'S ALIIIIVVVE!!! :lol:

Started right up last night - revved really high at first with the "choke" on about halfway but with just a little bit of choke it actually idled pretty smoothly. I think the idle is a little high, maybe about 1500 but it's hard to tell because the tach needle is busted off about a half-inch from the base. :roll:

The only issue I noticed right away was that it's slow getting back down to idle speed when I revved it up. All 4 carbs passed the "clunk test" with flying colors and the butterflies really snapped shut after I lubricated all of the linkage so I'm hoping maybe it's just the throttle cable and/or hand control that's a little sticky. Otherwise it was very responsive and didn't seem to miss or hesitate at all when I revved it up.

EDIT: just read another thread that suggested this type of issue could be coming from a vacuum leak. I'll try the propane test tonight.

I'm going to build a manometer and vacuum synch tonight.. any tips are greatly appreciated!!

I'm sure the air mixture screws need some adjustment too.. I would really love to colortune this thing but don't think I can shell out the $50+ bucks to get one... might try to find someone in town that has one I can borrow.

Anyways, thanks again for looking guys.. I never would've made it this far without this forum.

 

Re: Bringing a '82 XJ750 Maxim back to life-might need some

OH - almost forgot to mention, I got that busted screw taken care of using the "hogfiddles method" on page 1. Thank hogfiddles - you da' man!

Here's some proof with a shiny new screw courtesy of chacal! :lol:

 

Re: Bringing a '82 XJ750 Maxim back to life-might need some

That's a nice sound when a XJ roars to life, isn't it. However I would not waste your time trying to sync it until you track down that vacuum leak.

Keep us posted!

 

Re: Bringing a '82 XJ750 Maxim back to life-might need some

Did you find you had an easy or difficult time pulling the carbs?

I was working on a parts bike I have, and had to remove the air to carb boots on #1&4 to be able to pull the carbs out.

 

Re: Bringing a '82 XJ750 Maxim back to life-might need some

Kudos - you know, pulling the carbs really wasn't too bad. It only took about 20 minutes total (not bad for a guy that's never owned or worked on a motorcycle!). I pushed all of the boots into the airbox though so that was a huge help. I think I expected it to be a lot worse becuase of some of the threads I read on here. Putting them back on was a lot worse for me though - probably took about 40 minutes and cost me a half a fingernail and various cuts & scrapes all over my hands from trying to push those boots back through the airbox. There's probably a better way to do that part and I have a feeling it'll be easier next time if I have to do it again.

BTW, what part of Minnesota are you in?

 

Re: Bringing a '82 XJ750 Maxim back to life-might need some help

So you ended up pushing them in, rather than pulling them out?

The rubber on that parts bike must have been badly weathered - because that would have been impossible, although my runner's boots are softer.

It's too bad that airbox isn't designed to get pulled apart..

 

Re: Bringing a '82 XJ750 Maxim back to life-might need some help

High idle and reluctance to back down can also come from simply having the idle screw set too high. Turn it counter clockwise and see if that helps.

 

Re: Bringing a '82 XJ750 Maxim back to life-might need some

Well I've been picking away at things...

Turns out the "hanging rev" issue was due to the throttle linkage still being a little sticky.. lubed it up and now is snaps shut fine and is OK for the time being but I have a feeling it will be a recurring issue unless I break everything down and replace those throttle seals. It also wants to stick open at about 3/4 throttle.

I was going to take a stab at vacuum synching tonight but turns out my petcock is leaking like a MF'er. It was already in need of a rebuild but I took it off the take for a quick spray-bomb and now it leaks like a siv where it mates up to the tank... time to e-mail chacal.

Here's a couple pics for fun:

temporary rattle can job - not perfect but better than it was!


Petcock:




Home-made manometer:

 

Re: Bringing a '82 XJ750 Maxim back to life-might need some

Well I was getting ready to take a video and post it here to see if anyone could help me figure out why my throttle was sticking wide open but the old man figured it out - turns out I had the clamp for the #3 carb-to-engine boot out of position and it was rubbing and causing the linkage to hang up. Easy fix, thankya XJ gods!! Good lesson to always put things back together EXACTLY how they came apart.

I'm really surprised how smooth it's running right now after just a bench synch.. hopefully going to vacuum synch tomorrow night with the home-made manometer, maybe some light air/fuel mixture screw adjustment by ear, and tearing apart the petcock to clean and "restore" - hopefully that goes well thanks to the tutorial on here from Bigfitz.

As soon as that's done it's time for a first ride.. can't wait!!

Oh, and I completed the Basic Rider Course this weekend and got my motorcycle license today - STOKED!!

 

Re: Bringing a '82 XJ750 Maxim back to life-might need some

I AM THE MASTER OF THE UNIVERSE!!!! Don't ya love that feeling when all of your hard work finally pays off and things actually work the way they're supposed to?

While I was waiting for a petcock rebuild kit from Chacal (got here in less than 48 hrs. with express shipping) I vacuum-synched the carbs with the setup pictured above. I was actually pretty surprised how easy it was but I guess I have this site to thank for that. I didn't realize until the next morning, however, that I completely forgot about blocking off the YICS passage. I noticed a huge improvement in the way it ran so I'm tempted to leave it as-is but I may go back and try it again for kicks after everything else is done and I've put a few miles on it.

Re-assembled the petcock with new parts from Chacal and took the bike out for our maiden voyage together last night. Ran like sh**t at first and I got that sinking feeling that I would be battling carb issues for the rest of my life... then I realized that I forgot to hook up the vacuum line to the petcock, DUH! I guess I was a little too excited to go for a ride. After clearing up that little snafu she runs like a raped ape! Pulls strong and smooth.. didn't notice any burps, pops, or sputters. YAY!!!

Now just waiting on more parts.. brakes, tires, 3rd attempt at a turn signal lens, etc. Will try to post some updated pics tonight or tomorrow.

 

Re: Bringing a '82 XJ750 Maxim back to life-might need some

Finally got the new brake shoes and tires done and went for the first "real" ride last night. About a 30 minute ride with my dad. All went pretty well but when we got home it was idling high and hard to start about 15 minutes after I shut it down. I searched some forums and this seems to be a fairly common issue. I'm going to reset the air mixtures, re-synch, and maybe replace the vacuum line just to be safe. Hopefully that will help...

So far not a bad bike for "free" (I think I'm into it for about $450 now). Here's a couple of quick pics (new tires are Pirelli Routes):

 

Re: Bringing a '82 XJ750 Maxim back to life-might need some help

Somewhere along the line you checked the valve clearances, right?

 

Re: Bringing a '82 XJ750 Maxim back to life-might need some help

Yep, absolutely! All within spec - but good looking out, BigFitz!

 

Re: Bringing a '82 XJ750 Maxim back to life-might need some help

Congratulations on getting it going!! I'm jealous - my bike is still in the "is it worth all of this effort" stage.

I have the exact same bike so it's been fun to follow your progress.

 

Re: Bringing a '82 XJ750 Maxim back to life-might need some

Thanks WileyDan.. it feels good to know I'm not the only one looking at this thread! Good luck on yours man.. I checked out your thread & definitely looks like you're making some good progress!

I ordered a used XJ1100 headlight from andreashweiss from the"parts for sale" threads... should be here within the week and I'm hoping to ditch the square lights and guages to clean things up and just go with the single round headlight..

does anyone know if I'll be able to bolt that right on to the factory mounts from the square headlight or is it going to take some modification?

Also - my speedo doesn't really work. It usually hangs out around 20-25 but jumps up and wigs out every once in awhile. I'm not too concerned since I'm going to ditch the atari guages eventually anyway & I just velcro'd my Garmin GPS over the speedo! Actually seems to work really well and doesn't look toooo ghetto.

Rode the bike to work today.. first time going down the interstate. I was surprised that it was still up around 5K RPM's doing around 70 MPH. I know these are high-rev so I wasn't too concerned but does that seem normal?

Winds picked up throughout the day.. gusts over 30 should make it an interesting ride home.. cheers!! 8)

 

Re: Bringing a '82 XJ750 Maxim back to life-might need some

Yes. High strung SOBs. Get used to hearing it more like 6k, and constantly lifting on the shifter, hunting for one more gear...think everybody with one does that.

Looks good! Like the valve cover respray

 

Re: Bringing a '82 XJ750 Maxim back to life-might need some

I am converting mine to round gauges and lights. I also changed to the round buck horn style chrome bars too. It is not just plug and play. There is a whole lot of re-wiring to do, and one biggie is the headlight plug. On the 82 750 Maxim, the healight plug is from the Atari. The round gauges on the other models and years are not that way. I haven't done the bucket wiring yet, but when I do I can let you know what I do if you do not come up with something first.

I didn't even try the original square light bracket on mine since it was in such bad shape and rusty. But...what I can tell you is the round light brackets do not fit the 82 750 Max triple tree properly. The lower mounting bolt is on the opposite side. I have a post about it somewhere in by build thread.

But fear not, there is a quick and easy for parts swapping that will make it all work properly and be plug and play , so to speak.

1) Get the upper and lower tree and wiring harness hoop from an 83 750 Maxim. (if you wanted to use the round style bar as well) If you wanted to keep the original aluminium bars, then use the 82 upper tree with the 83 lower. Yamaha only did the Atari and square light on the Maxim 750 in 82.

2) For the gauges, the round style from 82 and up for the 550, 650, or 750 will work, but 81 and prior have a mechanically driven tach and the 82 is electrical.

3) If you are not into wiring and do not want to fool with all the cutting, splicing, re-routing, making new terminals (or taking out the wiring and re-arranging them in the plugs), then the quick and easy on the wiring end is to get your hands on a good harness from an 82/3 650, or 83 750.

As for the 1100 headlight, I am not certain if it is the same size or not.