1982 XJ750 starter chain guide

I've discoverd that my starter chain guide has broken, pieces of it had jammed the gear selector, removed them through access behind shifter mechanizm bike still runs and seems ok.
My questions is,
How Important is this guide? how safe is it to run without it? replacing it involves splitting the cases.

anyone?

 

most likely there's still some in there, so it might happen again.
the chain in a 750 can flop around and take out a little pipe that oils a bearing on the alternator

 

It will happen again, as soon as more big hunks break off.

Not only will the chain (which also drives the alternator) flopping about damage the oil jet Polock mentioned, but eventually the metal bracket at one end of the guide will break.

Other than potentially locking up the shifter without warning, the problem isn't super-immediate. But once the chain guide starts breaking up, it's time to start planning to deal with it sooner than later.

 

Thank you, I appreciate the advice and knowlege.

Looks like I'm splitting the cases this weekend.

 

Before you do that, get a factory service manual and study the procedure well, ahead of time. There's a lot involved and some very important details involved in reassembly.

 

No Doubt!
I've been reading that book for about two weeks now!
I started today, got the engine out.
so far the procedures have been spot on, and I'd have been lost without the manual.
I'm taking my time, got to do this right the first time!

 

Good work, Hope you are taking pictures!

 

Pay close attention to the use of Yamabond (or exact equivalent) sealant around the oil passages; the manual explains this very specifically.

 

the guide i got wasn't exactly like the original, # of bolts. it may have been a bit wider too because i had a time getting it in place until i took a bit off the side with the grinder, see what you find.
the starter clutch is right there, might want to think about changing that while your in there.

 

Thanks again, Adrian1, Bigfitz and Polock, Joining this forum is certainly paying off big time.
I do have one question, pulling the alternator rotor, what size thread will i need to pull it off? I have determined that it's 16mm, but how many threads per mm?

again, many thanks.

 

A quick trip to Harbor freight tools, bought a pully remover and installer set.
worked like a charm.

moving on.

 

Got the casses apart gentelmen. and it is the starter chain guide.
All three hold down bolts were still in the upper case, along with three pieces of the guide, found most of what I had not already gotten out as well.
the oiler for the alternator took a few nicks but it's not bent, or damaged other than some surface scratches. Engine is very clean inside, and it came apart very easily. no damage to the chain, or starter clutch. everthing is so very very clean.

Step by step.

 

Gentlemen,

Got it all back together, now a new problem, and I'm almost afraid to ask, but I'm experiencing a binding up of the transmission.

the engine runs great, clutch works, can't find "neutral" seems to be in gear with green light on, and when in "gear", letting out the clutch kills the bike, rear wheel stops turning.
My fear is that the selector forks are not where they need to be.

before I go take it back out and trear it all apart again, any suggestions?

 

Check to see if the Kickstand switch/indicator is stuck. If the bike thinks the kickstand is down it will kill the engine when you put it in gear.

 

lets hope you saw the #'s on the shift forks and did that right, although i don't think they fit any other way.
have a look at the ratchet thing on the end of the shift drum, see that it moves thru the gears.
if you tie the clutch back should be able to spin the wheel and go through the gears and watch the shifter ratchet mechanism.
there is a tricky part to lowering the lower case to the top case, a shift fork can swing around and not engauge, remember anything about that?

 

I never dismantled the sift forks or gears, I kept the "lower" assembly intact during repair to chain and guide. in fact, I never took the head or cylinders off either. removed the connecting rod bolts to pull the crank out and slipped a new chain in, putting it right back together.

The manual only states that the number two selector fork needs to be between the2nd and 3rd gear pinion, and if it's not, that it will be impossible to fully close the gap, it went together easy.
It's not the kickstand switch, I test drove it, and as soon as I tried to shift down to first, the rear wheel locked up, and the bike almost died, I put the clutch in and it coasted.

I'm thinking I have to split the cases again, I'm going to examine the gear shifter drum first, make sure it's lined up right.

thanks again for all the advice.

 

there was more chain guide material wedged in the input shaft gears.


snapped off a clutch spring bolt taking it apart again, hope to get it going again in a week.