Tomos/Amal jets?

First I would like to thank all that helped with the rev limiter questions. I set my timing up as far as it will go and that made a little difference. I still have some problems though. The bike runs good when the temperature is 50* out, but really runs bad (the cutting out thing as before) at 75 -up. Is this a jetting problem? For those that did not see my other postings my bike is a 95 Targa LX with a 70cc kit. The 15mm Amal has a #45 main jet. I raised the needle to both mid and hi grooves, top groove works best. Plug is a NGK #-7 and is a dark brownish-gray, oil is still rich. On warm days it runs okay for the first few miles and then starts to cut out AT TIMES after 7 or 8 miles. It does not cut out all the time, it's more of a in and out kind of thing. On cool days it runs very well and only cuts out slightly after 12 or more miles. What do you all think? I really need to get this fixed, but I could sure use some suggestions. Ride Safe...Butch

Re: Tomos/Amal jets?

Reeperette /

Sounds like a minor fouling problem, possibly combined with temperature/humidity affecting your mix.

Why a #45 jet ? #51 is stock for most Tomos at 50cc - and I would think one should jet a bit richer when going with a larger cylinder...prolly around #56-#58.

I woud try a richer main jet, with a lower ratio mix...see if you can get more gas in there, with slightly less oil, see if that burns any better...and it should burn cooler, in cause this is a heat-related problem.

That's just educated guesswork, tho...take as ya will.


Re: Tomos/Amal jets?

Ron Brown /


>The bike runs good when the temperature is 50* out, but really runs bad (the >cutting out thing as before) at 75 -up.

If this were a mixture problem, this sounds like too rich, try turning off the gas and see if you speed up just before it runs out of gas.

>top groove works best

If this means the top groove in the needle, which lowers the needle the maximum amount, this also points to a too rich problem. Have you tried running with no air cleaner?

Another possibility is that you have a heat related problem in the ignition system.


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