Transmission woes...

[gareth]

I finally got my carbs dialed in nicely, ditched the pods, went back to the airbox and the bike is flying. I got the off-the-line grunt back, and I opened up the airbox to get enough air to the carbs to match the flow of the pods up top...


I fitted the XS750 final drive a few months ago and I'm wondering if the newfound power off the line and taller gearing has somehow caused trouble.

Sometimes when I'm gearing down from second into neutral, the transmission will lock up. When this happens, the bike will stick in neutral, and since I have a heel-toe shifter, it needs a hard heelkick down to free it. If I still had the regular gear shift on the bike, I doubt that I would be able to jerk it free with my toe, it really takes a hard thump to get it unstuck. This is happening more and more frequently now. I almost thought I was stranded the first time it happened. Then I kicked it and it freed up...

It doesn't happen every time, mainly slowing down for a traffic light and making my way back to first gear. Along with this, is a reappearance of a "second-gear" problem. The previous owner had done the dremel fix before I picked up the bike. I have had no problems for the last 4k miles. I didn't recognize the symptoms at first. I used to ride a Honda V65 Sabre and when second went, I could hear the cogs rattling and jumping. On my Special, it just sorta feels like a turbo kicking in momentarily. If I take it easy on second, it doesn't happen. But with the taller gearing of the 750 mod, and a heavy throttle, I can make the bike stutter on demand, and only in 2nd gear.

SO..
Do I have two problems or one? Could whatever is causing the "sticking on decel" be the reason that the gears are not engaging fully and causing the stutter on acceleration? Anyone want to hazard a guess?

I wasn't around to watch when the PO repaired the gear and I have no idea what his skill level was. Just how many times can I redo the Dremel Fix before a new gear set is in order..?

I know I'm probably going to have to go back in there, but this bike is my daily year-round driver now.
I would like to have all the bases covered if I was to spend some time dismantling and repairing. Perhaps buy a full transmission, just in case??

Regards,

Gareth.

[subike]

PO may have done the dremel fix, but did he reassemble the gears corrctly?
I was reading in another thread recently about how Yamaha had assembled the gearbox in the factory, wrong, putting a spacer on the wrong side of something, and that error was also in their service spexs.
If this was true, then that may be the problem.
Just a direction to think about, I am sure other more xsperianced may either xsplain or rebuke my thoughts.

[motoman]

Sorry guys.....Yamaha didn't assemble any of tranny wrong.......some just think the need to re-invent the wheel so to speak. Doing the tranny fix, think most know my opinion doing the washer swap while it's apart. Gareth, for starters pull the shifter cover and put tranny in second gear and check shift pawl alignment making sure both marks line up. If it's off just a line width shifting and especially downshifting can cause tranny to do strange things. The screw and lock-nut on shift shaft even though tight can still allow cam to rotate a bit causing the marks to mis-align on shift pawl. A series of speed shifts can cause this to slip to(kinda reminds me of the p$$s poor design of the OEM cam chain tensioner). Although you might question PO's work, that lower tranny assembly will only go back in if assembled CORRECTLY. As for the dremal-fix, who knows if he even got aggressive enough, kept same angles,etc. Too many variables there to even take a shot in the dark. My first suggestion would be a start, and as you know only takes a short time to check.

[DGXSER]

Check the shift pawl alignment as motoman stated. Also look at the shift drum pins to be sure none are misaligned or misinstalled.

The other option is to look at the shift forks themselves. Depending on the POs knowledge or wisdom, they may have found a shift fork damaged by their POs and not noticed or replaced it. I have found more thna a couple wiht the shift forks eaten up from the PO standing on the shifter to hold it in gear when the "machine gun" effect starts.

[Crusty Snippets]

Gearbox

I got lucky and found a guy that knows more about these bikes than anyone else in these parts.
He told me the gearbox can be fixed permanently so it works properly.
Also he knows how to put in an electronic ignition.
I will be making many changes in the warmer months of 011.

Crusty

[Crusty Snippets]

[QUOTE=gareth;302488]
I fitted the XS750 final drive a few months ago and I'm wondering if the newfound power off the line and taller gearing has somehow caused trouble.

I was thinking the gearing could be a bit higher.
How is is working for you other than the gearbox problem?
I am always looking for 6th gear.
But I will be riding two up often. However we weigh 275 total, and naked.

Crusty

[DGXSER]

Hey Crusty,

I have ridden with the 750 FD on and love it. If you do any amount of highway riding, it is the bomb schnizzle!!! I have found I need to down shift to fourth or even third more than with the 1100 FD, but the lower revs in the upper speeds more than makes up for it. And at 250 total, your less than most of the riders here by themselves

Ohhh...and I recommend night time riding if your gonna go naked!!! LEO will notice it a little less!!

[CatatonicBug]

The 750/850 FD mod is wonderful for the cruiser-style rider. Not exactly preferred for the canyon-carver though. I catch myself on the highway at 65mph, still in 4th gear sometimes, happily suprised with a "6th" gear!

[gareth]

Sounds like good advice to check the alignment behind the gear cover first..
I need to change the shift seal in the cover anyway..its been leaking oil for ages and I have postponed changing it for ages. I can see that the spring inside the seal, similar to the one in a fork seal, is now exposed..Maybe the damaged seal is not supporting the shaft enough and causing a mis-alignment??
Dunno. Will have to have a look...

[davidsymons53]

electronic ignition?

Not to hijack your thread Gareth, but... Crusty tell me more about "Also he knows how to put in an electronic ignition".

David

[Crusty Snippets]

Not to hijack your thread Gareth, but... Crusty tell me more about "Also he knows how to put in an electronic ignition".

David

This guy, Super Dave, has a bone yard in Langley BC.
He built his own frame for his 1100 Yamaha, switched to chain drive and raced it on the paved tracks.
He told me about how the ignition wyres can get damaged over time and about the gearbox problems.
Said it is easy enough to change to an electronic ignition.
My engine is running well enough at the moment so I have not pursued this.
But it on my list of things to do for 011.
It will be mid December before I am in his area again.

Crusty

[Guy_b_g]

XS11 already has an electronic ignition.

[cywelchjr]

This guy, Super Dave, has a bone yard in Langley BC.
He built his own frame for his 1100 Yamaha, switched to chain drive and raced it on the paved tracks.
He told me about how the ignition wyres can get damaged over time and about the gearbox problems.
Said it is easy enough to change to an electronic ignition.
My engine is running well enough at the moment so I have not pursued this.
But it on my list of things to do for 011.
It will be mid December before I am in his area again.

Crusty

But it IS an electronic ignition. No points involved whatsoever. If he's talking about electronic advance, all one needs to do is source and install the ignition system from an XJ1100 with it's fully electronic advance system. The 81 use a partially electronic advance system, but still retain the vacuum advance which is what flexes the wires. If you don't care about fuel economy you can eliminate the flex by disconnecting the vacuum advance, which will not affect performance but may adversely affect cruising fuel economy (like these things are in any way economical anyways).

I'd certainly like to switch to EFI with associated computer controlled ignition, but that seems to be pretty pricey so far, and there is no "kit" in it's entirety that I know of (the computer comes as a kit, but all the other stuff has to be source individually).

[subike]

was the 78-9 vacum advance modual the prefered unit for performance due to the longer advance curve it had?, Butter than the later short curve units?

[cywelchjr]

was the 78-9 vacum advance modual the prefered unit for performance due to the longer advance curve it had?, Butter than the later short curve units?

The problem is the later motors have a problem with that much advance and are very likely to knock with it. That is one of the reasons for the lower advance, and the replacement unit has even less advance to eliminate that problem. Yamaha claimed that the knock wouldn't damage anything, but it's scary hearing that kind of sound coming out of the engine.