loss of power

[trisha1963]

Hi I have a JM Star 50QT-13 07 erg,

We have had a lot of problems with it, and now the latest thing is a loss of power this has only happened since we replaced the stator and things, we have replaced the spark plug, set the gap as directed in the manual, it seems to be running rich as a sooty plug is what we have, and when we rev it up there appears t be petrol coming out exhaust, and we have a strong smell of fuel as well,


we have tried the air mix screw and no joy, it starts ok, runs ok other than no power, can someone suggest anything too check/try



thanks


trisha

[stirlinggaz]

hi,
have a look at the carb.
if there is an "enrichment pump" on the side of the carb, adjust it.
(whilst looking at the side of the carb, open & close the throttle. is there a cable pulling a little hammer type thing,with 2 nuts on it, little rubber shroud on it?)
i found out how these work by taking the carb off & pushing down on the little piston... only to have petrol squirted straight into my eye, at which point i screamed like a little girl, dropping the said carb in disgust.
when the throttle is wide open, it pumps/squirts extra fuel into the carb.
these are usually set up wrong & need loosening off to stop it pumping fuel in so early in the throttle opening.
if it doesnt have one of these devices on the carb, f*cked if i know whats wrong with it.
cheers,
GAZ

[Timmeh]

Hi, welcome to BCF.

First thing to do is get the carb apart and check for something like a stuck float, leaking main jet or other really obvious problem.

I have a feeling that the air screw might be a mixture screw, but without knowing the carb model we can't be sure. You could try to gently turn it all the way in until it stops (don't force it) and then wind it back out 1.5 turns.

For a single like yours a colourtune is the best and easiest way of getting the idle mix right.

Hope this helps.

____________________
GSXR400 x2 | '94 RVF400 | '93 TZR125 4DL (again)
20:22:30 BLUEX5: i would love to be forced to undergo a**l plugging with different sizes
20:48:18 Temeluchus: comp you hunk of smouldering homos3x you

[yuri2085]

Also check air filter might be clogged.