Best 4 Cycle Combo?

[Tommy22]

I'm trying to come up with a solution, despite pouring a ton of money into my current project. My 4 stroke 49CC kit from eBay has a lot of problems. The belt drive setup it came with is basically garbage. I would like to switch to something more reliable. It seems no one makes a transmission that fits a straight shaft - Other than maybe a Q-drive, but there is very little information about those available. Nothing on their website about what they fit, etc.

I don't want to use anything with the oillite bushing, because when they get hot, they just expand and lock up the clutch. Terrible design.

At this point I'm not sure what else I can do besides buy another tapered shaft engine, and then go with a Bike Berry double chain drive transmission.

What kind of transmissions are available for a Predator 79CC? I'm thinking of going that route if I have to start from scratch. Just a little worried about the weight, etc.. Don't want to break the frame (It's a Micargi).

Also, I live in a pretty hill area. So I need it to climb decently. Currently have a 46T rear sprocket, but may go with more teeth if needed.

 

[Deleted member 26224]

By design the q-matic is the best kit. It is pricey though. Or you could get a clutch and jackshaft kit for cheap but it would be a chain primary which is worse than a belt. The clutch in the qmatic is the common stock 10t max torque which having a reduction in front of it, runs perfectly on the stock spring and shoes and cooler too.

Oilite bushings work great. They will grenade if you do not oil them. One or two drops after every ride or every hour of riding.

 

[Chainlube]

If you go with the Predator, a TAV would be a good choice for the trans. The output shaft is 5/8" so a drive shim is required, I don't think you can get a TAV with a 5/8" drive.

 

[Tommy22]

By design the q-matic is the best kit. It is pricey though. Or you could get a clutch and jackshaft kit for cheap but it would be a chain primary which is worse than a belt. The clutch in the qmatic is the common stock 10t max torque which having a reduction in front of it, runs perfectly on the stock spring and shoes and cooler too.

Oilite bushings work great. They will grenade if you do not oil them. One or two drops after every ride or every hour of riding.

Mine was locking up after just a few miles of driving. I sanded it down and soaked it in oil for a week before reinstalling it. Drive it a couple miles. Parked it for an hour, drove it a few more miles and it started locking up again. I just don't see how they can work. It will expand after it gets really hot and seize up. Granted, it is hilly where I live, so I imagine that makes it work harder/get hotter sooner.

Regardless I'd like to have something that will run for an hour straight (if I want to) and need little to no regular attention.

 

[Tommy22]

If you go with the Predator, a TAV would be a good choice for the trans. The output shaft is 5/8" so a drive shim is required, I don't think you can get a TAV with a 5/8" drive.

Yea, I may start looking that direction. I think that will have more power for the hills, etc.. just not sure on fitting the frame, the frame holding up, and need a mount plate (they seem to be a bit rarer to find).

 

[Chainlube]

If you're handy with power tools a mounting plate is easy to make, not only that it will be custom fit for your bike.

 

[Tommy22]

If you're handy with power tools a mounting plate is easy to make, not only that it will be custom fit for your bike.

I'm a little handy..no welder at the moment (my welding sucks anyways). More of a time thing than anything else - I want to tinker, but not get into any super involved fabrication. Just don't really have the time.

Gasbike has this 79cc kit in stock (at least according to their website)
https://www.gasbike.net/products/79cc-monster-80-bike-engine-kit-4-stroke

I imagine the go powerstports converter would work much better, but not sure how well it would work on a bike.

 

[Chainlube]

Before you buy from them you may want to check this thread, https://motoredbikes.com/threads/br...after-2-miles-replacement-ideas-advise.56508/
A high speed rotary tool and a drill press will get your mount made, pick up a couple nice muffler clamps from a auto parts store and you're almost there. I wish I had one of those little engines in my shed, I'd make a new intake to allow the engine to be mounted with the cylinder pointing up.

 

[Tommy22]

Before you buy from them you may want to check this thread, https://motoredbikes.com/threads/br...after-2-miles-replacement-ideas-advise.56508/
A high speed rotary tool and a drill press will get your mount made, pick up a couple nice muffler clamps from a auto parts store and you're almost there. I wish I had one of those little engines in my shed, I'd make a new intake to allow the engine to be mounted with the cylinder pointing up.

Yea, it sucks there are not more reputable companies in this business. I'd be happy to pay more for something that actually works.

I just rode the bike again.. Was fine for a few minutes..Then same issue. Will not idle on it's own..Just wants to bind with the oilite bushing. Maybe I could try filing down on the bell/oilite bushing more aggressively.. I don't know. Just seems like a terrible design. There should be a nice sealed bearing there instead. Problem solved.

 

[Deleted member 26224]

If you go with the Predator, a TAV would be a good choice for the trans. The output shaft is 5/8" so a drive shim is required, I don't think you can get a TAV with a 5/8" drive.

I see you recommending it often. Have you built a setup like this?