Tomos resurrection, part 2 -- Fuel?

Christian Baekkelund /

A little while back, I was given a dead Tomos Bullet. I have never messed around with mopeds before...

I have followed the first few steps on most of the on-line guides for moped repair. I took out the spark plug, and tested it, and when I back pedal the moped it sparks (however does not when I pedal forwards). The spark plug looks fine also, no buildup or I guess that's a check?

Next, I looked inside the cylinder and when I back pedal, I can see (and hear) the piston moving up and down (however, does not when I pedal forwards, but I assume that's normal?) That seems to be ok? Also, it won't backpedal easily with the spark plug back in place, but I assume that's normal as well?

So I guess the next possibility is fuel? No fuel is flowing properly? Is there anything I can do to discretely check for this? Fred's guide recommend squirting a little gas in, then trying to start it up? This guide ( recommends spraying a little carb cleaner in... Any other possible methods? Should I be able to tell from just looking with the spark plug not in place or similar?

Also, there is a valve on the fuel line...I'm guessing it's a fuel cutoff, but does anyone know by default which way allows fuel to flow and which cuts it off (toggle goes from "up" to "down"). I tried both positions just to be thorough, and I have a hunch "up" is the proper position to allow fuel to flow?

Finally, the fuel in the moped is very old (around a year). I suppose I should drain it out and put in some fresh fuel? How should I drain the old fuel? Is there a hose or valve in particular?

Thanks for any help...I appreciate it a lot. :)

Re: Tomos resurrection, part 2 -- Fuel?

See Ya Moped Army /

First, drain that stale gas out of the tank. Secondly, remove the petcock (fuel valve) and clean it thoroughy. It's most likely clogged up with debris. Next replace the fuel line and inline filter if it has one. Next, drop the motor and remove and clean the carb.

Fuel flow problems are easy to correct. If you want to check to see if fuel is flowing to the carb, remove the fuel line to the carb and turn on the fuel valve. Point the hose into an empty jar or coffee can. If gas flows from the petcock, any fuel delivery problems would have to be at the carb.

Re: Tomos resurrection, part 2 -- Fuel?

If you turn the engine over with the spark plug out you can see a mist of gasoline coming out of the spark plug hole if the engine is getting fuel.

Also, replace the spark plug!!!

I spent a lot of effort before, cleaning the carb etc. only to have the bike not run. Well at least till I replaced the old plug, then it fired right up. Replacing the plug could save you a lot of effort if that is all it needs.

Of course, replacing the gass and cleaning out the carb is not a bad thing to do too.

Re: Tomos resurrection, part 2 -- Fuel?

Christian Baekkelund /

So, I checked the petcock and fuel is definitely flowing through no problem. It is probably a little grungy and the fuel line is not in great shape, but no doubt that fuel is definitely flowing.

So, I guess it's the carb, then?

Time to take out and clean the carb?

Re: Tomos resurrection, part 2 -- Fuel?

Christian Baekkelund /

Ok, now I'm really confused...

1) I took out the spark plug, and tested it and I get a spark.

2) I back pedal the moped with the spark plug out, and I hear the sound and see the cylinder moving.

(Note: On both of the above steps, those things only happen when I'm back pedaling it, not forwards...that's normal, right?)

3) So it must be fuel? I emptied the fuel tank and the drain on the bottom. I squirted a bit of fuel into the cylinder, put back the spark plug, tried it again, and STILL nothing.

So now I'm baffled. Anyone?

Re: Tomos resurrection, part 2 -- Fuel?

I repeat myself, try a new sparkplug!

Re: Tomos resurrection, part 2 -- Fuel?

As far as pedaling backwards, I'm not sure about Tomos peds but most that I've seen engage the engine when pedaled forwards.

Re: Tomos resurrection, part 2 -- Fuel?

Christian Baekkelund /

Well, with the spark plug out, it will pedal both backwards and forwards with ease....but nothing happens when it's pedaled forwards (no spark, no piston movement), only backwards.

With the spark plug in, it will again pedal forwards, but it's not starting up. With the spark plug in, it will not really pedal backwards at all (you could force it a bit, but not really).

Is this normal?

Re: Tomos resurrection, part 2 -- Fuel?

Christian Baekkelund /

I'll try swapping out the spark plug anyway, but like I said, I seem to get a decent spark from it.

It _might_ be a bit worn, but definitely getting a spark.

Re: Tomos resurrection, part 2 -- Fuel?


I am around and available saturday if you want an extra pair of hands....let me know!


Re: Tomos resurrection, part 2 -- Fuel?

John Joedicke /

Hey people this is a kick start. Put the plug in and kick it over, what do you know ,it will probably fire and start. Use the choke.

Tomos resurrection, part 2 -- Fuel?

Christian Baekkelund /


So, I have been tinkering on it and tinkering on it...I changed the transmission fluid, and lo and behold it started up!

It definitely needs more work, but it runs. Things I noticed:

1) The first few minutes of running, it put out a large amount of exhaust....not billowing clouds, mind you, but definitely more than it should during normal operation...that seemd to go away after a few minutes though.

2) The gear shift if pretty jerky. It really stutters when it hits that 18mph or so mark and shifts up.

3) It doesn't sound very great...I'm not really sure how it should sound, but I think this still doesn't sound too good...not terrible, but just could use some tuning. It sounds very rattle-y in general...and in high speeds I can hear a high pitched whine...In any case, I saw some stuff on tuning elsewhere, so I'll try that next I guess.

Thanks to everyone that's replied! This moped is back from the dead!

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