one chirp, another, then a squeal

[BA80]

Greg: put a piece of green Plastigauge under the bolt head and tighten it down to see if there's any clearance.

Well, I've never "shimmed" any gears so I probably won't run into the same problem you did. I am a strong believer in the "if it ain't broke don't break it" theory.

I know that Ivan and Tod both have had them back out and to my knowledge there was no gear shimming done there either.

Just an observation.

[3Phase]

Well, I've never "shimmed" any gears so I probably won't run into the same problem you did. I am a strong believer in the "if it ain't broke don't break it" theory.

That's a good theory and I should follow it myself more often!

If everything is still stock on your bike the Plastigauge should get pretty much obliterated equally on the end of the output shaft and the bearing inner race when the bolt is tightened; might actually be a good time to use up some of that pesky red Plastigague that no one ever uses but always seems to get packaged along with the green.

I know that Ivan and Tod both have had them back out and to my knowledge there was no gear shimming done there either.

Just an observation.

I think Tod re-shimmed 1st gear but didn't trust the new clearance because it might have been able to pop into gear by itself. I don't remember if the bolt started acting up before or after that. Ivan's a top-notch mechanic and was a pro for a while. Bolts really ought to know better than to unbolt themselves on his bike so I don't have any idea what happened there!

[bikerphil]

Some of the 81's have an aditional spacer underneath that countershaft bolt. There is a Yamaha tech bulletin somewhere explaining it.

[Brent]

Ah ha! An intake leak! That's a whole lot better than low or no oil pressure and a lunched cylinder head and camshafts!

Greg: put a piece of green Plastigauge under the bolt head and tighten it down to see if there's any clearance.

Bill,
You are correct. Loctite was not used on the bolt torqued to 51 lbs. (Seems like the only change from stock was moving the position of one washer.) No plastiguage clearance check was done.
Long test ride after 2nd gear fix was about 40 miles. After about 30 miles, the low oil pressure warning light came on. Engine sounded fine, oil level OK. Bill did you find bad oil pressure sending unit or bad connection in wire, as you suspected?? Is low oil pressure warning light functioning properly now?

(yes, I was there)

[madmax-im]

Seems like alot of folks forget that every time you pull the carbs off you have to re-synch them each time they're re-installed. You are doing this right?

[DGXSER]

Interesting thought on the first gear washer issue. I know I have moved the washer on second gear on a couple engines now and never had any issue with the gears or that bolt. The part that seems odd to me though is that this would imply that the middle driven gear is being pinned against the side of the case, I know it is keyed onto the shaft, so it definitely spins. I will have to pay closer attention to that next time I pull the tranny.

As to synching, it should be done here as there was a vacuum leak that was repaired. Something that changes engine or cylinder performance. That is the key to when you need to synch, anytime you do something that can change the performance of any one of the cylinders. The synch is the method to even out the performance of all four cylinders. (at least at idle anyway).

Merely removing and re-installing any component including the carbs would not necessarily mean a need to synch. Just like pulling the tank, or the coils and re-installing would not change the synch. If you however clean the carbs, or adjust a mixture screw, then yes, a synch would be recommended. Or if you change coils, you could easily change the performance and therefore need to synch again.

[natemoen]

As to synching, it should be done here as there was a vacuum leak that was repaired. Something that changes engine or cylinder performance. That is the key to when you need to synch, anytime you do something that can change the performance of any one of the cylinders. The synch is the method to even out the performance of all four cylinders. (at least at idle anyway).

Merely removing and re-installing any component including the carbs would not necessarily mean a need to synch. Just like pulling the tank, or the coils and re-installing would not change the synch. If you however clean the carbs, or adjust a mixture screw, then yes, a synch would be recommended. Or if you change coils, you could easily change the performance and therefore need to synch again.

I do agree with you, BUT, even just pulling the carbs out for whatever reason even if not touched you could change something unintentionally. Even not seating the carbs at the exact same depth in the boots changes things, may not ve significantly but it is still a change that could have an effect. So why not put the gauges on so that you know.

[3Phase]

You're going to make me look at the fiche....

Oh, man, it's been a while since I've done this... changing the 2nd gear washer(s) around doesn't move the output shaft. I don't remember now so I'll have to look at the parts fiche but there is a ridge in the middle of the output shaft that separates the right-hand and left-hand sides of the gear stack.

The spacers/shims on the right-hand side of the output shaft position the shaft in the case and set the gear spacing. The special bolt at the case bearing holds the whole Magilla tight against against the inner bearing race to keep the shaft and gears from floating back and forth and rattling like a 70-year-old Russian tractor used to find mines in Moscow after the war.

The spacers/shims on the left-hand side of the output shaft only set the spacing for the gears and the end of the shaft floats in the left-hand bearing inner race.


The later transmissions use a single-row ball bearing in the right-hand side of the case instead of the original double-row bearing. The new, thinner, bearing needs a spacer pressed into the case along with it because the case and snap-ring groove are cut for the wider double-row bearing.

The spacer/shim under the special bolt works with the new, thinner case bearing to keep the bolt head in equal contact with the end of the output shaft and the inner bearing race.

Phil, I'd have to read that Tech Bulletin again to remember exactly what Yamaha was up to. Unfortunately I don't have time to dig it up right now because I'm riding up to Ventura to meet Roo and his girlfriend. We're going to see DSO (Dark Star Orchestra) and groove for a few hours so I hope y'all have as much fun as we're going to have tonight!

[bikerphil]

going to see DSO (Dark Star Orchestra) and groove for a few hours

Sweeet, have a good time, Dead music lives on forever.

[wmaddox3]

Resynch?

Here we go!

Brent - thanks for remembering. I had forgotten about that first ride. The oil light hasn't been acting up. But I didn't get to ride yesterday- but the flooring is almost done.
Is it a consensus here that I need to resynch?
I have had the carbs in and out maybe twenty times while trying to get the misassembled airbox back in.

[wmaddox3]

Boots

I forgot to mention that the leak had been only for maybe 3 mins of idling on the centerstand.

[BA80]

Seems like alot of folks forget that every time you pull the carbs off you have to re-synch them each time they're re-installed. You are doing this right?

+1 on that Ben