GT 550 Starter clutch gear problem

[gminkmonster]

I am trying to fix the electric starter on my 1975 gt 550. when the starter is engaged it just spins the outside ring of the starter clutch gear. It looks to me that the starter clutch gear should be all one piece but the outer ring spins freely on the inner hub that slides on the transmission shaft. It is the old style starter clutch. The rest of it seems to be in good shape. I just dont understand why the outer ring spins on the inner part. Were they origianally press fit together and if so could I weld them back together. I hope I explained this problem good enough that someone can answer my question.

[Alan H]

The inner and outer - on the earlier type anyway had roller bearings which were held in by small springs and cups. When the electric motor spins, it causes the rollers to lock between the inner and outer parts, spinning the engine. If you weld it up the engine will always be in mesh with the starter motor and will cause the starter motor to spin very fast all the time until it goes pop. So use the kicker until you can repair it!!!
Have a look at this link from on here
http://www.oldjapanesebikes.com/gt550/g ... ngine.html" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;

There's lots on the net about these clutches, and they come up occasionally on the bay of E.

[gminkmonster]

I understand all of that. The problem i have is with the gear itself not the clutch. The center of the gear that goes inside the clutch and the outer part with the teeth are seperated and looks to me like it needs to be one piece. If you look at the pic of the old style gear in the link you gave me, the snout or neck that goes inside the clutch and the outer ring with the teeth are not one solid piece and the outer ring with the teeth juist spins on the neck. I may have to post a pic if this dont make sense. im talking about welding the gear together into one piece not welding the gear to the clutch.

[Coyote]

The large gear us held to the clutch basket with 3 very stout rivets. If these rivets are sheared, it would do what you are saying. Gear spins but nothing else happens. Are we getting warm yet?

[gminkmonster]

Its not that gear but the big one behind it that engages with the starter gear.

[gminkmonster]

Here is a few pics of what im talking about. Should these two pieces come apart like they do??

[Coyote]

Ah, I see your problem now. That all should be one piece. I can't really tell what you have there but the OEM gear was a machined casting. They were never pressed together. If I am looking at that correctly, the snout is the part that goes in to the starter clutch rollers. Right? If so, that should be all one piece
I have one of those gears on the bench here. It's not in the best of shape. The gear is fine but the face of the snout is kinda smeared from an earlier starter clutch explosion. Yours for $10 + shipping.
I suppose you could weld up the one you have, but I'd be very careful that the weld doesn't interfere with something else. Pinning would be better but would cost a lot more.

[gminkmonster]

Awesome, now we are getting somewhere. Next question, how tightly or loosely should it fit on the transmission shaft? This one seems too tight to me. If i am looking at it and thinking correctly, it would need to allow the shaft to turn inside it or else it would try to spin the starter when the motor is running. The one i have fits really tight. I wonder if it seized on the shaft and that's what broke the gear. The starter was broken when i bought the bike, so i have no idea what happened to it. Although the original starter was in pieces inside when i took it apart leading me to believe that maybe the engine was spinning it. My email is gminkmonster@msn.com, email me the info so i can get the money to you for the gear. Thanks alot.

[Alan H]

According to the parts manual, there are two types of starter clutch gear, 12620-34003 for J, K, & L models and 12620-34004 for M models. they aren't interchangeable, but you appear to have the earlier unit. I had one like that on my J back in '72 and it was OK for many years with good oil in the box.
It should be in one peice and I wouldn't recommend welding it as it would have to be perfectly centred and 'true'.
I would hang it on a 'wall of knackered bits' which you find in some sheds/garages if I was you!
The technical engineering terms for the one you have is ''Knackered' or 'FUBAR'.
Looking at the oilways cut into the inside of the bush which goes on the shaft, I would expect it to have a little play so that it can spin freely when oil is present between the bush and shaft, but not wobble.
Dunno how it could have sheared like that, someone had to really try hard.

[Alan H]

Just seen this on eblob, but you'll have to be quick!
Clicky clicky, quicky quicky!!!

Not cheap, but it looks like it's all there.

You'll still need the other bit though that went AWOL, but this looks like a complete starter clutch.

[Alan H]

Also check #26 on this link (clicky)

[Cliff]

Yes, the old style gear was two piece. The center hub was sweated into the gear. I see in the picture that your hub has turned blue from friction. That much heat would cause your problem! The bushing is probably distorted as well, that's why it's tight on the shaft.
Replace the gear ONLY if the the rest of the starter clutch is not damaged if you plan on using the electric start, but if the hub is blue the rollers must be too!
If your not going to use the electric start, replace the gear, remove the rollers and assemble the unit. I did that to mine and used the kick start for almost 30 years!!
Keep an eye out on ebay etc. for an updated clutch or even a later model parts bike or engine. The updated "Borg Warner" style clutch is the way to go!
Cliff.

[gminkmonster]

Actually the rollers look ok. The rest of the starter clutch looks good also. What do you think could have caused the hub to over heat? Is there an oil passage that i should check? As far as i know the electric start hasn't worked for at least 15 years. I just want it to work.

[Coyote]

All those parts run in a constant bath of oil once the transmission is filled. Cliff has a point that things might be distorted. If you don't have an indicator, borrow one and check the shaft for run out before you put it back together. It should be dead true. If it wobbles, you're gonna have problems. Major vibration if nothing else.
Check the fit of the gear I am sending. If it is tight, I would be very suspect that the shaft is bent or out of round. It should slip right on and spin freely.

[gminkmonster]

Did you get my address?