First time moped builder introduction - 1991 Tomos TT Bullet A3

Hi everyone. I've built a handful of motorized bicycles over the last 5 years. I know, not the same thing, but figured it was enough experience to learn a moped. Anyway, I found this 1991 Tomos TT Bullet A3 for $275 here locally and decided to buy it. Engine turns over, carb definitely needs rebuilding and I was planning on pulling the engine and rebuilding it with new gaskets and seals. Previous owner says he replaced the ignition coil and magneto. I'm going to fix it in its stock 50cc configuration, and when it's running right, buy a 70cc kit, carb, and pipe for it.

Needless to say, I have a bit of work cut out for myself. I plan on videoing the whole process and documenting it here. I'm looking for people who have experience with this particular build to tell a few pro tips to a clueless noob who's cutting his teeth on this thing. Any advice and tips welcome, particularly any regarding 70cc kits (I'm eyeballing one at Treatland) and also carburetors for 70cc kits.

If you're someone who loves 2-Stroke mopeds and you like to share knowledge and experience, chime in so I know who you are.

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Re: First time moped builder introduction - 1991 Tomos TT Bullet A3

Here is one of the tt that I own needs finshed don’t they all lol ... I’d say get the treats read kit with the 10mm piston pin only kit for the a3engine ? and go with at least a 15:15 carb and intake get a pipe of you’re choice and you’re blasting 50

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Re: First time moped builder introduction - 1991 Tomos TT Bullet A3

I was thinking something a little bigger on the carb... perhaps something 18-20mm. Does the 15:15 get enough extra airflow for the extra 20cc? Do you know how the reed valve effects the carburetor placement after the kit is installed? Can the carb return to its home or does it need a new intake manifold to go with the kit?

Re: First time moped builder introduction - 1991 Tomos TT Bullet A3

15:15 will not perform like 19mm on the top but the 15:15 will rev and have a lot or torque the intake you can run any a35 intake at that point one like you have now with the carb under the body or a side mount intake you’re choice

Re: First time moped builder introduction - 1991 Tomos TT Bullet A3

I have this pipe here. I was thinking about chopping the stock exhaust and welding this one up in it's place.

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Re: First time moped builder introduction - 1991 Tomos TT Bullet A3

That pipes sweet do it looks like you have a dell carb already look o. The side and see what size.

Re: First time moped builder introduction - 1991 Tomos TT Bullet A3

It's a Dellorto SHA 14:12. Tiny guy. Will a 15:15 fit?

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Re: First time moped builder introduction - 1991 Tomos TT Bullet A3

Brandon Weiss (Detective brandon to you) /

Whoa! What is that pipe from? I'd bet set up with a nice header you'd make a goodly bit of torque with it. Interested in seeing how you mount it, don't mount it to the swingarm (if that wasn't obvious)

Re: First time moped builder introduction - 1991 Tomos TT Bullet A3

15:15 will fit no problem where did that pipe come from I’m interested now !

Re: First time moped builder introduction - 1991 Tomos TT Bullet A3

I bought the pipe on Amazon for $30. it was advertised as a pit bike expansion chamber. Saw some videos where Arrow Motorized Bicycles used a pipe just like this on their race bikes, so I bought it. Originally it was for my motorized bicycle engine, but it turned out to be cheaper to modify my original pipe, so I had this one left over.

I was going to chop the original mount off the expansion chamber and weld a little mounting bracket to it that matches up with the original mounting arm for the pipe on the bike.

Re: First time moped builder introduction - 1991 Tomos TT Bullet A3

So funny, I just hacked a similar pipe onto the same color tomos! Still in need of a few bits, fender, front fairing and a lil tuning boy lemme tell ya, she’s a ripper.

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Re: First time moped builder introduction - 1991 Tomos TT Bullet A3

Brandon Weiss (Detective brandon to you) /

> Jackerz ! Wrote:

> -------------------------------------------------------

> So funny, I just hacked a similar pipe onto the same color tomos! Still

> in need of a few bits, fender, front fairing and a lil tuning boy lemme

> tell ya, she’s a ripper.

That's a Proma Lowboy? Looks like it! I have one on the Cimatti 86, really torquey...but that probably because the header is super long

Re: First time moped builder introduction - 1991 Tomos TT Bullet A3

That's a very nice bike. What kind of performance are you getting out of your TT Bullet build?

Re: First time moped builder introduction - 1991 Tomos TT Bullet A3

Dirty30 Dillon /

The OP's pipe is just a generic pocket bike chamber.

The Other is a Proma LowBoy

Re: First time moped builder introduction - 1991 Tomos TT Bullet A3

Luke Stroehlein /

Welcome! I also started with motorized bicycles. Once you browse the parts on treatland and 1977 mopeds you'll realize that stock just ain't good enough. I guarantee you'll be in the performance part of this forum in no time. Happy tinkering!

Re: First time moped builder introduction - 1991 Tomos TT Bullet A3

ephraim zimbalist jr /

put a bigger jet in that dell carb,58ish mm,and a biturbo pipe,maybe the one you have.a larger carb wont help on that little 49cc engine.....you should gain 8-10 mph.thats the cheapest way

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