Hi Malcom,

There should be two openings into the venturi on the tops of the carbs,
they will have vertical mounting points for tubes. These tubes are used
for the vacuum operated petcock (which you won't be using on a go-kart).
With these un-obstructed, you'll have running problems, as it will be
sucking in fresh air directly into cylinder 2 and 3.

Try blocking these up, or just connecting them together with a hose or
something, this may fix your problem.

The two that run out of the in-sides of the carbs are just breathers, i'd
prop these up in a spot that's higher than the carbs.

Are you running with the standard exhaust? If you're running a free
flowing exhaust then you'll either need to change needle possitions and
pilot air screws, or re-jet to get the correct mixture. I have a feeling
that you'll need to do this anyway, because you're not running an airbox
(which is asking for trouble!).

Backfire out the carbs is (as i've read) usually caused by running lean.

I'd suggest doing a plug-chop (cutting the motor while under load,
coasting to a stop with clutch in) after initially cleaning the plugs and
reading the plugs to get a better feel or what the engine's doing.

Float levels are checked with the float bowl off, you measure off the carb
body to the highest point on the float, with the float just resting on the
(sprung) needle. From memory it should be 20.5mm +- 1mm, and they should
both be set to the same level).


Cheers,


Carl


>
>
> After a long time I have now fixed my wiring got a new CDI, got
> spark, put new head and base gasket onto my GS250FWD with a lot help
> from you guys. Thank you
>
> Now I have reached the part where I want the thing to run. I have it
> in a go kart. Spark is strong. Exhaust is complete but no air box.
>
> It will only start and run on full choke. it takes ages to accelerate
> and will only get to a max rev of aprox 5000 RPM it is a rough and
> after it has been running I feel the exhausts and it is hot in
> cylinder 1 and only warm in the others. It seams to run very rich and
> whilst trying to start can backfire out the carbies.
>
> I have the Carbie set up as:
> There are four hoses on the carbies 1 is fuel inlet. and other 2 are
> return that I have running to the ground (nothing comes out) and the
> other I don't know I have tried it un-blocked and blocked.
>
> Another question is how do you check the float levels. I am used to a
> window and level mark.
>
> If anyone can help It will be much appreciated.
>
> Thanks
>
> Malcolm
>
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>
>
>
> Yahoo! Groups Links
>
>
>
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>
>


--
Carl Johnston
BiziWorks Support
W: www.biziworks.com.au
E: support@...
P: (03) 8415 1788
F: (03) 9417 7336