Getting Biturbo for my 2008 Tomos Streetmate

Just looking to get performance. 28 mph isnt cutting it on Main st. Heard the Biturbo improves it to 38 which is great. I heard that just getting a new exhaust and not upjetting the carb or something can score the piston. Is this true? I really... Really dont want to mess with the carb.

Re: Getting Biturbo for my 2008 Tomos Streetmate

You will have to mess with the carb, kiddo.

Re: Getting Biturbo for my 2008 Tomos Streetmate

You will have to tune your carb, slightly, and there is no way the pipe alone will give you a 10mph boost. The stock gearing does a lot to restrict your top speed, but on the flipside, it gives you mad takeoff.

Re: Getting Biturbo for my 2008 Tomos Streetmate

"messing with the carb" requires undoing maybe 8 nuts/ screws max.

Re: Getting Biturbo for my 2008 Tomos Streetmate

You have to upjet the carb, its easy to do.

Re: Getting Biturbo for my 2008 Tomos Streetmate

How come at half throttle, I cant go past 28. Full throttle sounds like fuel is getting into engine but not firing. I believe its called bogging? So I bog out at 28 and I would believe that exhaust flow is being restricted by the stock exhaust. Also what will provide more power on the gearing side?

What do you recommend for a jet size?

Re: Getting Biturbo for my 2008 Tomos Streetmate

Recommended jet size? Looking for more power but I would like to be able to hit 35, some where along that speed. Hills give me trouble as well but i think that would be for all 50cc.

Re: Getting Biturbo for my 2008 Tomos Streetmate

In order to hit 35 (about 56 km/h for me), I had to drill out my airbox, use a biturbo, change my 31t rear sprocket to 28t, and upjet my main jet to 62, and idle jet to 32. A lot of time went into tuning my idle mixture for a good takeoff. I'm still trying to determine if my main jet is the correct size. Plug chops only give you part of the picture.

But every bike, setting, etc., is different. You really do have to learn as you go along. I think the best thing for you to do is to try one thing at a time. ie: add a biturbo, and upjet a size or two to see what the difference is. Then you can start trying other things as you learn more and do more reading. Reading and actually feeling your engine four-stroke at top speed (telling you that you need to downjet) are two entirely different things.

I can tell you that the hill-climbing performance with the stock gear and pipe are better than what a smaller rear sprocket and biturbo will give you. The Biturbo is tuned for more top end, at the expense of low-end power. Hill-climbing is first gear is whack, though. Any classic moped with only one gear will struggle way, way more than you do.

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