Help me figure this out.

[Guest]

I need to pull the clutch basket out of the FZ to get at the shift shaft as it won't shift out of neutral. Unfortunately, the crankshaft is stopped in a position where one of the counter balance lobes is blocking the removal.

The Clymer manual says to screw an 8mm bolt into the left end of the crankshaft, lock it in postion with a nut and turn counter clockwise to move the crankshaft.

Now here is what I don't follow, the bolt screws in clockwise and while you can tighten down the nut it does not lock the bolt in position. Turning the bolt counter clockwise as instructed will just back it out.

At first I thought the instructions should have read turn the bolt clockwise when fully seated. That will turn the engine in reverse of its normal direction but will that cause a problem? There are also other references to this procedure in the area of checking valve clearances and they also state "install the bolt on the left end of the crankshaft and turn counter clockwise".

I am really confused and can't proceed until I get this figured out.

Any thoughts or ideas?

[Agemax]

try tightening up the lock nut a bit tighter if you can and when you try to rotate the bolt anti clockwise, get another spanner on the locknut and use dome slight clockwise pressure on it to keep the lock nut tight.
or put a longer bolt in and put 2 lock nuts on. one to tighten up to the crank and the other to lock the lock nut to the bolt........

also if it is an easy job, remove the spark plugs which will help rotating the crankshaft easier

[chuck hahn]

As Adrian said..if its jammed real good and tight then it should move the crank. Or a longer bolt and 2 jam nuts..then use the nut closest to the crank to turn it.

[spyug]

Thanks guys. Once I calmed down and had a good night's sleep I did as you suggested and with no compression on the engine it turned like the proverbial hot knife through butter. Slick as you please.

With the clutch basket out of the way I could test the shift mechanism and it is indeed the problem. With some vice grips on the end of the shaft, I can select 1st gear then back to neutral but no higher. As I don't see any broken parts I'm thinking it is a case of worn out springs. I haven't pulled the shaft out yet to get a closer look but will do that shortly.

While I could rob the spare engine, there is no point in doing it half azzed so I'll order up new springs. I don't want to be doing it again.

I'll post up some pics when I pull the shaft out.

Thanks for the support and encouragement. I knew I could count on you guys.

Cheers,
spyug

[GregT]

Good luck with the selector mechanism...I had an FZ750 motor dropped off at the weekend to be split and a replacement gearbox installed.
Symptoms were difficult shifting and eventually, missing gears. It lost top completely.
There's a GS1000 on the bench to do first but if you've any problems just ask as I've done a few of these now....

[almarconi]

As I don't see any broken parts I'm thinking it is a case of worn out springs

A shift fork could be bent and that would be difficult to see while they are installed.

[spyug]

As it turned out, the shift shaft mechanism is not the problem it is indeed something related to the drum and or shift forks.

With the shift shaft out of the way, I can move the drum from neutral to 1st and back again but can go no higher. There was nothing wrong with the shift shaft mechanism.

So now its a case of pulling the engine and splitting the case. As I have never done this before and it appears quite complex, I am going to try it on the spare engine first. I will likely need to get into the spare engine anyway as I may need its drum or forks.

I am not looking forward to this but it can't be avoided.

Wish me luck and thanks Greg for the offer to bounce things off you. I greatly appreciate it.

spyug

[Agemax]

have you tried turning the transmission while trying to shift up. if the dogs on the gears are opposite each other then it wont shift, turning the trans allows them to mesh correctly while shifting.

just a thought before you pull it apart.......

[almarconi]

Depending on the mileage of the spare engine, you may be better off with a new drum and forks. If you have reason to believe the spare engine was mistreated I would not waste my time with used parts. I am going through this same scenario on the RF900 I am working on. The PO destroyed 2nd and 3rd gear. Bought used tranny on ebay, looked fine in the pictures (this was first noob mistake). Only until I had taken the gears off the shafts could I see the worn dogs and slots on the gears. Ended up replacing 3 gears and all the clips and bushings. One fork was broken the other two were worn so all new shift forks. I didn't want to chance it so I replaced the shift drum, shafts, pawl assembly and all the other small parts while I was in there. Also added a factory pro shift kit. Spinning the shafts by hand, I can now shift from 1st through 5th. It is a bit stiff but once under power it should shift fine now.

[GateKeeper]

Going to followo your progress on this,,,,,in case my FZ750 has to go through the same work......

I really hope not, but one never knows....

Best of luck on the rebuild

.

[spyug]

Depending on the mileage of the spare engine, you may be better off with a new drum and forks. If you have reason to believe the spare engine was mistreated I would not waste my time with used parts. ]

I just came to the same conclusion as I checked the shifting and it too will only go to first and back out. I was hoping to avoid buying parts since they are very pricey, forks are $69 each and the drum is over $350.

have you tried turning the transmission while trying to shift up. if the dogs on the gears are opposite each other then it wont shift, turning the trans allows them to mesh correctly while shifting.

No I haven't done that but I wonder just what that then telss me if I get it to shift up. won't it just happen again. I'm afraid I'm a transmission newbie so I don't follow a lot of this. But thanks for the suggestion.

spyug

[Agemax]

to give you an idea, try sitting on a bike without the engine running. without using the clutch, try shifting into 1st gear. if it wont go in rock the bike to and fro, the gear will engage. then try shifting up the gears with the bike stationary, you wont be able to.
rock the bike to and fro again and you will be able to shift up through the gears, and back down again.
same principle as turning the trans by hand while trying to shift the drum by hand.
if you can shift up and back down again by hand,while turning the transmission by hand, then there is nothing wrong with the drum or selector forks.

[chuck hahn]

Yes on what Adrian says..the tranny needs that little jiggle so the shifter ratchet can reset for the next gear selection. It resets automatically with the bike rolling while driving because the trannys motion doesnt allow the ratchet to hang up..thus you never feel it under normal riding conditions.

[spyug]

Gosh you guys are great. I still don't comprehend it but I did as you suggested and turned the transmission by hand while also turning the drum and as you mentioned it shifted like it should. So you are saying its all good and I can bolt it all back together?

Just so I try to understand this what causes this to happen in the first place? I haven't ever experienced this before. Originally this happened as I was riding at fairly low speed slowing down to a stop sign. I had difficulty getting first but then when I did get it, it didn't want to shift up. Any more information would be terrific as the more you know the easier it is to understand and deal with anything similar in the future.

I'm now going to try it with the shift shaft back in position to see how that works.

I think I need a course in bike transmissions to round out my education.

Many thanks guys.

cheers,
spyug

[chuck hahn]

The little jiggling lets the ratchet reset....yes its good to go. Button her up and get to riding.