salfter
New Member
Long time, no post...picked up a 4-stroke kit (one of these, by the looks of it) from an eBay seller (no, not he-who-shall-not-be-named, but another one based in California) last summer, put it on a bike, and got maybe 100 miles out of it before the gearbox started acting up. The clutch would grab at idle while stopped, which would either stall the engine or make it bog badly. When I popped it open, the clutch bell was a bit "wobbly" and the gear on it showed signs of accelerated wear. I tightened things up a bit more, threw in some grease, and put it back together. I got a few more miles out of it (maybe up to 120) before it went back to its misbehaving ways.
I parked it in the garage last August or September and didn't get back to it until this evening. I had to pull on the starter forever to get it running, but the engine still seems to be good. The clutch almost seemed better for a bit, until I took a quick trip around the parking lot.
I've spent a few hours catching up on the past few months' posts, figuring out which way to go next. I had some crazy ideas about hanging a Delco 10SI (the alternator you'll find under the hood of most '70s and early-'80s GM vehicles, available everywhere dirt cheap) off of the engine and going to a series-hybrid configuration, but with only 2 hp on tap, I'd think it would be better to avoid as many energy-conversion steps as possible.
One possibility, if someone sells the parts, would be to fix the gearbox I already have, but everything I've seen about the three (?) gearboxes available for 4-stroke bike kits suggests that I ended up with the weakest model. I think I'd end up tearing into the gearbox more than I'd really like. There's also the small matter of not having found somebody who sells the parts.
The other possibility is a replacement. eBay only seems to have rack-mount GEBE kits and frame-mount kits from he-who-shall-not-be-named, but there seem to be a few more vendors in the business now than there were a few months ago. In particular, this looks interesting. The gears (especially the one attached to the clutch bell) look more substantial and look like they ought not wear out as fast. The whole unit looks like it's a bit longer than what I have right now, but that's nothing that a chain breaker can't fix. Other people's feedback indicates that it holds up a bit better, and is also a bit more quiet once it's been broken in.
According to this, it should work. Has anyone else switched gearboxes on a 4-stroke yet? I'm a bit bummed at the prospect of shelling out more money, but if it'll get my bike running again for less than the cost of replacing both the engine and the gearbox, I might just bite the bullet and go for it.
I parked it in the garage last August or September and didn't get back to it until this evening. I had to pull on the starter forever to get it running, but the engine still seems to be good. The clutch almost seemed better for a bit, until I took a quick trip around the parking lot.
I've spent a few hours catching up on the past few months' posts, figuring out which way to go next. I had some crazy ideas about hanging a Delco 10SI (the alternator you'll find under the hood of most '70s and early-'80s GM vehicles, available everywhere dirt cheap) off of the engine and going to a series-hybrid configuration, but with only 2 hp on tap, I'd think it would be better to avoid as many energy-conversion steps as possible.
One possibility, if someone sells the parts, would be to fix the gearbox I already have, but everything I've seen about the three (?) gearboxes available for 4-stroke bike kits suggests that I ended up with the weakest model. I think I'd end up tearing into the gearbox more than I'd really like. There's also the small matter of not having found somebody who sells the parts.
The other possibility is a replacement. eBay only seems to have rack-mount GEBE kits and frame-mount kits from he-who-shall-not-be-named, but there seem to be a few more vendors in the business now than there were a few months ago. In particular, this looks interesting. The gears (especially the one attached to the clutch bell) look more substantial and look like they ought not wear out as fast. The whole unit looks like it's a bit longer than what I have right now, but that's nothing that a chain breaker can't fix. Other people's feedback indicates that it holds up a bit better, and is also a bit more quiet once it's been broken in.
According to this, it should work. Has anyone else switched gearboxes on a 4-stroke yet? I'm a bit bummed at the prospect of shelling out more money, but if it'll get my bike running again for less than the cost of replacing both the engine and the gearbox, I might just bite the bullet and go for it.