Starter Gear Fix!

[Stone Co Rambler]

So the starter still engages with the engine running but just a short "squeal" or "honk", not actually trying to engage and turn the motor....if that makes sense.

When I use just the starter to turn over the bike, it runs for just a short second after the engine is running and has the honk or squeal I am describing.

This is a common issue on old BMW airheads and usually is an indication of some loose magnets or other components in the starter motor itself. We always called it the "honky".

Might not be a deal, not sure. If I rev the engine while its turning over/starting....no one will hear it or know any different.

That being said, if there is an issue I can correct, I'd like to.

 

[suntrakr]

Just so I'm 100% clear as I put the clutch back in and seal her back up and want to avoid over tightening any components. The nut in the picture (not me, the one I'm pointing to), is the primary drive gear nut and I need to tighten it to 65 ft-lbs.

 

[vsop-dk]

Great post subscribed, thanks

 

[XSLeo]

That small gear shouldn't need to be torqued unless you loosened it. You shouldn't loosen it unless the gears are damaged. The clutch comes off without removing that gear.
But yes, if loosened it should be torqued to 85 ft./lbs. in my 70-74 book, 58 to 82 ft./lbs. As in my 74-77 book, 65 ft./lbs. in my 78 book.
The spec changed over the years but 65 ft./lbs. should be ok.
Leo

 

[MikeC23]

I applied this fix and want to test things before I button the side cover back up. What should I see when I hit the starter button?

 

[Johnny Boy]

Just aquired a 79 xs650. Kick starts ok. Elec start very erratic and noise like gears slipping.
Is gear#4 problem. If so - where is this gear?

 

[dps650rider]

What we really need is a permanent fix, eventually the spring will be a problem again. I have retensioned it, replaced it with a new OEM spring and replaced the gear. Works for a while but eventually (as it is now on my bike) it's a problem again.

 

[pamcopete]

On my trusty '78/E that had this problem, I ordered the gear but while waiting for the gear, I just removed the return spring and was able to use the remaining bit of gear teeth while waiting for the new gear. When I finally installed the new gear, I left the return spring out. Ran it that way for 15 years. The return spring prevents the gear from fully engaging. The only down side is that the gear will creep over when the bike is tilted to the right and rattle, but not having the return spring allows the gear to fully engage. i think that 5twins tried this as well.

Note: the gear will not creep over to the right when riding a hard right turn. Also, the gear is completely disengaged when the engine starts as the engine spins the gear and it retracts on the screw shaft.

 

[dps650rider]

I remember reading that before, probably written by 5 twins. Not sure I like the idea of leaving the return spring out but I will look at this option when it gets cold out. Really wish we could get a better wishbone spring.

 

[wingman1946]

I have not yet been into the bottom of the bike. But it is coming soon. Is this return spring you mention the same as the wish bone? I don't find a spring by that name.

 

[5twins]

No, it's different. It resides next to and just inbound of the #4 gear with the drag clip. It is #2 in the diagram below. You can see it in Gary's second pic in the 1st post. Yamaha calls it a "spring, compression", not a return spring. But that is what it does, helps return the #4 gear to its disengaged position. It's not much of a spring, only a couple coils of thin wire, less coils actually than the drawing shows .....

As mentioned, I've had mine removed for several years now. I can't really say whether it improved the starter engagement. The only drawback I've encountered is a slight rattling sound coming from the right cover if I park the bike on the sidestand while idling. I think gravity is allowing the #4 gear to drift down and chatter against the crank gear without the spring in there. I will probably put it back in one of these days but it's not a major, pressing issue.

 

[wingman1946]

Thanks 5 twins. I am here still waiting for some nylon screws to arrive so I can fire the old gal up. Hopefully.

 

[triumph68]

it really works thank you so much garyr the sound that came out of the starter made the hair on the back of my neck stand up . im as about as mechanically minded as a retarded chimp and i managed to tighten the spring and get it back together in under an hour i have ordered a new gear to replace the one in there as it is so worn like the the one in the original photo now i have the confidence to do the repair thanks again triumph 68 australia

 

[mikeh36]

I was trying this today and I've run into a problem. The first time I put everything back together the starter engagement was better but it still slipped on occasion so I took everything back off and put the gear in the vice again for another attempt. When I put everything back together and was testing the starter I didn't realize that the snap ring didn't seat properly and it blew everything off onto my lab. Put it all back together and now I can't get the snap ring to tighten itself down enough. I'm about to go hunting for a replacement snap ring but if I can't find one can I substitute a C-clip in it's place?

 

[GeorgeOC]

Thanks to all for this very helpful thread. Can I ask those that have performed this fix... Is this statement correct... We're increasing the spring tension to 6lb by slightly compressing this 'looped' portion of the clip?

 

[mikeh36]

That's correct. I could never get it to that tension but it is still very improved over what it was.

 

[GeorgeOC]

That's correct. I could never get it to that tension but it is still very improved over what it was.

Thank you Mike, much appreciated. While I am at it, is the conventional wisdom also employing the revised "loop" orientation?

 

[weekendrider]

Yes and it helps to remove the clip from the gear while tightening/clamping. It is possible to break them if you squeeze it too much.

 

[mikeh36]

Thank you Mike, much appreciated. While I am at it, is the conventional wisdom also employing the revised "loop" orientation?

If my memory serves that's where mine was by default. I saw a video where it was suggested that you actually put the loop back in the groove for it but there was other gearing in the way when I put mine back in so I left it like your image. I didn't want to tear things apart if I didn't need to. As I get older I trust my mechanical aptitude less and less and my mechanic father in law isn't 10 minutes away anymore.

 

[5twins]

See post #10.