Honda Spree and Elite 50 Forums

Hello, first post here. I just bought a 87 Honda Aero 50 and this seems like the first thing I need to fix before I start this up. The Driven gear has sheared off. It also looks like someone tried to weld the nut on which is probably why it sheared off in the first place.

Can I get a replacement for these? How difficult would it be to swap out?
Thanks!

So what happened here was the PO sheared the splines off the crank, probably b/c the nut was loose or fell off. Those splines are what drive the belt. Since the splines were gone, he welded the pulley half to the remainder of the shaft, along with the nut. Welding would have removed the temper off the shaft plus the shaft was weakened anyway... and it broke.

The correct fix is you need to replace the crank with a new one. This is a complicated job and you may just want to run down a replacement engine instead.

Thanks for the response! Does this look like the correct part?

dthibode wrote: ↑Sun Aug 12, 2018 11:30 am Thanks for the response! Does this look like the correct part?

No, that's the clutch shaft. You probably won't find a replacement carnkshaft for that in good used condition. You might but I would not trust it. Search for a new one if you are serious about rebuilding the motor. But I would take the suggestion from Noiseguy and track down a replacement motor that's in good running condition.

Thanks for the input. I have no idea where to find a new crankshaft OR a working motor.
Darn.

Ok, is something like this more like it? I'm sure this is a huge pita to swap, like you guys said.

Yes, the carnkshaft in second link appears to be correct. afaik.
Part numbers are same for both '86 & '87.

If I was going to swap in a different motor and let's say I couldn't find a working 87 Aero 50. Does anyone know what other options I have? Can I swap in something newer like an Elite motor? Thanks again for all the help!

dthibode wrote: ↑Sun Aug 12, 2018 1:17 pm Thanks for the input. I have no idea where to find a new crankshaft OR a working motor.
Darn.

Search this forum for swap/info threads. You could probably swap in a '94-'01 Elite SA50 motor (AF16) without too much trouble. The wires and motor/rear shock mount would be the major obstacles. To use an older style motor would be going backwards IMO

dthibode wrote: ↑Sun Aug 12, 2018 2:39 pm If I was going to swap in a different motor and let's say I couldn't find a working 87 Aero 50. Does anyone know what other options I have? Can I swap in something newer like an Elite motor? Thanks again for all the help!

I wouldn't focus on a running '87 Elite motor. I'd focus on any '87 Elite 50 motor you can find that has an intact crankshaft. Assuming your own motor isn't completely trashed and the replacement motor at least has usable bearings you should be able to make a runner from the two engines. FWIW the hardest job on the entire engine is replacing the bottom end bearings; it will be easier and more straightforward to swap everything to a case with a usable bottom end. You have to tear the whole engine apart to remove the crank anyway, so you won't be saving any work swapping the new crank into your engine. Of course, if the bottom end is shot on the new engine you'll have to replace bearings and seals anyway... on one of them. Pick the better looking of the two in that case.

dthibode wrote: ↑Sun Aug 12, 2018 1:23 pm Ok, is something like this more like it? I'm sure this is a huge pita to swap, like you guys said.

That crank may be correct but it's been sitting in a wet environment and per seller needs rod bottom end bearing replaced. I changed my mind; swapping *that* bearing is the hardest job on the engine. I've never seen anyone on this board attempt it; usually you send them off to be redone and it costs >$100. You have to press apart the halves with a +10T shop press, replace the bearing, repress it together, and then align the whole thing with deadblow hammer and sandbags, checking your work with v-blocks and micrometers.

Thanks for the info, it's super helpful. Right now I have my eye on a local that has an aero 50 almost complete, and they attempted moving a motor to it, looks like a newer elite from the pictures. They gave up on it but if I can get the bike for cheap, I may be able to scavenge the motor off it at least. That's a big maybe. Not sure if you're on FB, but if you can see this maybe you can recognize the motor from the pictures? Thanks.

Greetings:

That blue scooter appears to be a 1983 or '84 Aero. It has a completely different - down to bore & stroke - engine designated AB09, and was superseded by the AF05 Variated (SE05) engine that soldiered on from 1985 (no kickstarter, 2-bolt manifold) through 1993. Evidently Honda-san wasn't too happy with original 83 design, Honda's first 2-stroke in forever, and went back to the drawing board.

Thanks!

Basically there's only one part you need out of that mess, and it's the SA50 engine, only if it's in working order. The older Aero 50 is so unusual as to be... much less valuable except perhaps in part. I'm betting the SA50 is frame wrecked.