Fuel Tank liner(?) issues on new shiny '82 XJ750 Maxim

Oh good. I was worried that it might be a loose diverter plate in the collector.

Locktite, blue, everywhere that's not hot

 

HAHA ...we have ALL been there done that at one time or another...we overlook the obvious no worries great that it simple to fix. Cheers

 

So, as has been referenced in the daily Yamaha thread, I've been digging into an outrageous amount of lateral swing arm play:



Pulled off the swing arm, and yeah, the bearings are right done. Also is clear why the bearings are done: The left side spacer that sits inside the oil seal, between the bearing and frame, is missing. So, the only thing keeping the bearings in their races at all is the rubber oil seal. I've got new bearings and oil seals, will get a new spacer, but have a question:

The adjuster axle stub (the one with the 6mm allen head socket and ring nut) was on the left side of the bike, while the Hayne's manual says it should have been on the right side. Is the Hayne's manual correct? Does it matter? I'd assume it was just put together wrong, given the absent spacer, but just wanted to confirm.

 

Yes.

Confirmed!


Just think of all the other systems that the same level of attention-to-detail was poured into..........

 

Yeah; that's the misery and joy of old bikes. Can never assume the way something is put together is the way it's supposed to be put together

It's made more exciting because while the aftermarket repair manuals are very handy, they're not always absolutely reliable.

 

Swapped in my spare swingarm as it's bearings are fine. Reinstalled the axle stubs correctly, at specified torques.

Well, locknut is guessed at as I can't get my torque wrench in the locknut AND hold the axle stub with and Allen wrench at the same time and I figured a specification like 52 lb-in is pretty specific while 70 lb-ft is "snug that mofo down".

Swingarm moves up and down freely now, no scaryass sideplay. Can't wait to see how the bike rides now!

I'm pretty excited. Now I've fully disassembled and rebuilt (well, swapped, in the rear case) both front and rear ends, and both went pretty well. Feeling really confident about both now, so any future suspension related work should be cake.


Again, thanks everyone for all your help. It's been fun, educational, AND I've gotten a great running bike out of the process; the whole trifecta of "Is this worthwhile?"

 

So, as I mentioned in the daily thread, my Maxim appears to have spring a severe oil leak. Enough to go from full to empty in a day or two. I'm not positive of where it is yet (just noticed when I started her up to go to work) but it appears at quick inspection (in the dark) to be from the bottom of the left side transmission cover - no oil on the jugs or front of the motor, but a hell of a lot along the bottom of the left side.

Curiously, there was also a heavy "gassy" smell when I started the bike. Same method as always (full choke initially, immediately backing down to half) and I've never had that before. Not even "rich burning exhaust" but just gas.

Carbs don't appear to be leaking[edit: more than normal, 1 and 4 have slightly leaky boal gaskets but it's very minor], no smell of gas in the oil. Gonna clean it with brake cleaner, top off the oil and see if I can confirm where it's leaking from (and hopefully figure out what the deal is with the gas smell too) tomorrow morning.

 

Herm. Could be I panicked a bit unnecessarily.

Got home from work this morning, and checked up on my baby. Too much oil in it, which leads me to believe what happened last night was that with the oil light on, I popped the bike onto it's center stand and checked the oil.... but having just run briefly, the engine itself was full of (still sluggish, cold) oil, so it read low. I topped it up then and (*shudder*) drove my truck to work.

This morning, seeing it overfull, I drained the excess and got it down to a nice small bubble atop the sight glass, started her up and... sure enough, after a short time, oil light came on again. I know the level is good, but it's not done this before. Obviously, one potential issue is a hinky oil level float/sending unit. Is there anything else I should consider?

 

some of that oil might have got sucked up the breather tube to your airbox behind the filter, maybe look in there for a puddle

 

Hokay, back in the thread this stuff belongs in:

I've repeatedly thought I fixed my rattle, but alas, it persists.

I've gone through the bike multiple times, checking torque, making sure nothing's loose. I've just finished fully removing and dismantling my exhaust, replacing gaskets, cleaning it all out, checking for loose parts. Ensured the rear collector mount bolt (and it's full rubber mounting) is installed correctly. Opened up the rear end, checked brakes, changed oil. Not even the slightest bit of rattle in the collector or headers

Took it for a test ride before remounting my mufflers and without body panels and unnecessary chassis parts (painting stuff, still drying)... and still getting a metallic rattle at ~3000rpms.

I'm starting to wonder if it's the cam chain. I figure I'm about out of non-engine related causes. There's an automatic tensioner, but is there any way to know if it's working?

 

Take the valve cover off as if you were going to do a valve check turn the crank then turn it the other way and see how loose the cam chain is how far it turns before it gets tight.

when i did the valves on my bike it was how I knew I needed to adjust the tensioner.
yours is automatic and may need to be cleaned or the end replaced

 

Will check it once my helicoils get here. Have a stripped valve cover bolt hole (that previously held a helicoil) so I'm short a valve cover bolt at the moment, but it's not leaking and I don't want to disturb the gasket till I can get that fixed.

 

Pretty happy with how it's all going. Still waiting for the helicoil, though I'm seriously considering just clamping that corner (it's the front left bolt) with a c-clamp until I can get it fixed - I really want to get the valve cover off and check valves, cam chain tension and whatnot. Wish having that stripped hole fixed wasn't such a PITA.



She's come a long ways since March!

Finally replaced my flasher with an electronic one that's actually wattage independent (and adjustable!) and got the exhaust and such cleaned up.

Have a carbtune pro on the way, and looking to order a carb rebuild kit from Len on payday.

I've got three sets of carbs - the ones on the bike, and the ones from the second Maxim and the Seca. They're all the same HSC-32 carbs, but I haven't opened any of them. The existing set on the bike are running really well, so I'm assuming they're either synced or at least pretty close, and despite the apparent slight leak from the throttle shaft seal on #4 (can be seen on the pic above; but MAY just be from the bowl gasket - I think it's from the throttle shaft though) they seem to be set up pretty decent.

So, I'm thinking the best course of action for me is to tuck into one of my other sets of carbs, and do as good as possible a job on them, get them *perfect*, then swap out my existing carbs for the rebuilt ones. This way, I can keep riding while working on them[read: not feel pressured to do a fast job just to get carbs back on the bike during my soon ending riding season], have one set being cleaned and another set as a "let's look and compare" set though as I've never seen them run, there's always the possibility that things aren't correct on one or both of them. Install, sync, etc - then I've got the currently installed set to rebuild for my other bike (the Seca). That's the plan, at least.

 

I thought about this issue the other day when I came across this old thread, unfortunately you already had your exhaust back on. Post number 19 has the pics of the broken double wall pipe that was causing a rattle:

http://xjbikes.com/forums/threads/1989-radian-noise.34466/

 

That was something I was specifically looked for when I took the exhaust off. Was hoping to find that in fact as I've another set of headers available.

With that said, while I didn't find anything loose - I had each header off and shook them, then rolled/flipped them around a lot while wrapping them - it's not impossible that one is broken further inside but held by both ends so nothing was apparent when I shook them.

 

Definitely wasn't anything visible inside the ends of the pipes.

 

I believe the Seca carbs are jetted differently due to Seca having hotter cams. Somebody wanna confirm this? If so, it'd be best to use the Maxim carbs on a Max.

 

You are correct. Swapping the main jet end jet needle is all that's required though.

 

Righto, so I'll use the carbs off the parts Maxim, then.

Edit: Well, I'm not sure which set that is now. hah... Well, I guess I'll look at what jets are in each vs. stock jets. Needed to figure out what I have on hand anyways.

 

K-moe: I noticed in another pretty old thread, you noted that the cam shaft endplay ticking is due to the cam caps' tolerances, and that Yamaha would replace them but only if the customer complained (that is, it's not necessary, but it is a fix). I've seen posts previously on this, but hadn't realised it was the caps themselves vs. the cylinder head.

Did this affect all 750's of the era? Or was it just some? I ask, as having a fully spare motor, it may be worth checking. My Maxim's ticking is loud - likely due to 80,000k of tapping - so loud it's very noticeable when doing 120kph over engine and wind noise.

I'm thinking I could just try swapping out caps to see if I can find ones that are somewhat quieter, if it's that simple. Or just replace them, if replacements have the correct tolerances and are available(Couldn't find them in Len's Engine post, but may not be looking for the right thing)?