Hello!

Hey guys!

I'm new to the motorized bicycle scene but not to 2 strokes. I've actually been building and porting high performance 2 strokes for Go-Peds for a couple years so I'm familiar with how engines work and how to make them faster. I'm hoping to build a nifty little 2 stroke motorized bike in the near future.

I was wondering if those eBay bicycle engine kits are worth it and if replacement parts for them are easily available? I know there might be a sticky or something about this, but I'm having difficulty finding a clear answer on the forums (soory for the noobness). I don't have more then $300 to put into a kit which is why I'm looking into the eBay stuff.

CrazyCatLady said:

Hey, another Floridian with cat in their name! What's up? Those go-ped bigfoot scooters have a decent sized engine, don't they? What about one of those?

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The biggest bigfoot engine would be a 30.5 cc; they're pretty good and can rev up to 18k, which would be nice to have on a bike. Unfortunately I don't have the tooling necessary to rig up one of my Go-Ped engines

I think I'm going to go with a Jet kit from gasbike.com. What do you guys think? I've heard they were a good vendor and that the kit is one of the better Chinese ones. I was planning on looking over the internals before installing it after seeing that thread about the grubee kit with metal shavings in it.

I'm also going to try to see if I can adapt one of my cylinder reed valves to it. Hopefully the intake port's bolt spacing will work with the reed I have (crossing fingers!). I'm also planning on doing some porting and will try to measure the port timings since I figure some people may be interested in that.

Does anyone know what kind of revs the 66cc Jet can handle? I don't want to push the engine too hard and blow it up when I get it...

Sorry for the long post. This looks like a great forum and I'm excited to get my first MB built!

Dogtown Burner said:

well Catperson,
did you wind up porting the Jet? havent seen one for sale in quite some time now. done any more thread research?
if you have not, fyi the 66's are rumored to redline around 8k, and run comfortable high cruise around 6k. Reed valves are rumored not to work, as the engines werent intended to use them. something about port size/timing. also, do not raise or lower the ports---wider works. (this is just from threads i've read)
I'm curious what you have found, if anything. I'm also interested what you think the possibilities of a go-ped engine on a bike would be? maybe put a 415 chain & 8 tooth sprocket on the clutch and run to a (huge, I'm guessing) rear wheel sprocket?.
I Rode my nephews go-ped today, and whew! thats some power!!. if these china girls did that the "performance increase" pages on this forum would be a lot thinner. it'd be nice to see that kind of power on a bike. Although I'm guessing wheel size, torque, and clutch strength would play a major change-up game. going from a 10" tire to a 26" is significant. hence the intrigue...
any wisdom appreciated.

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Hey,

Man my last post was awhile ago, lol. Since then I ended up buying a BGF 66cc engine kit off ebay. I tore the thing down, looked over the internals and did some minor exhaust/transfer porting. All I can say is that these engines really are cheaply built... Unfrotunately I never ran the engine stock so I don't know if mine really does perform better than stock. All I can say is that it hasn't let me down once since I finished setting it up a couple of months ago. Since then I haven't really messed with it since my mb is my main transportation to/from work so I can't afford to have it apart. The cranks in these things really are horrendous in terms of their balancing and this has prevented me from porting the engine further. I see no point in doing so since the damn thing vibrates so badly. I'm used to smoothe running engines and the HT definitely is the worst I've seen in terms of balancing.

However, I will be throwing out the stock float style carburetor in favor of a walbro pump carburetor sometime soon. I just need to finish getting my mill set up so that I can fab an intake manifold. The walbro is much better than the stock carb so it should help my engine run smoother.

Also, you can reed the HT engines; you would just have to do some porting to the top end to get the most out of it. I run reeds on all my goped engines and do the portwork myself so I know that you can reed almost anything as long as you know what you're doing.

I've seen a few people put goped engines on their bicycles. They work great and with the right porting will easily outperform any chinese HT engine out there. I've built a few 50mph GoPeds so I know what those engines are capable of. If you visit Untitled Document that site might give you some good ideas on how to mount a goped engine with a little use of the search function.