Grasshopperr

I have a murnan modified sirio evo 2 that wont ever run right I have had twenty people to try to tune it and it will usually run good for five minutes then it starts running like $hit I am only thirteen and cant aford a new motor right now so if anyone can give me so tips or ideas on getting this motor to run right it would be great.

Thanks for your time, Chance Parker

Grasshopperr

The main thing it does is it will be sitting on my starter box and gradugtly the idle will go up untill it is so High I have to turn it of. I did not have this problem with my stock sirio.

Joe Chaplow

when you rev the engine holding the car in the hand, if after you rev the engine and the idle is high for some time but comes down after say 8 seconds... try leaning the bottom a bit more until when you rev the car up when holding in the air, after reving it all the way up (you should hear the car shift) the idle comes back reving high but it does not fall down... when you have this happen, now richen the idle... hopefully this helps. i am also new to the hobby, if i am wrong, someone please let him know.

Joe Chaplow

also, i have heard the carb is not that good on the sirio--- wich could be causing your problem. it sounds like the engine loses tune. if you have a novarossi carb, put that on it.

Grasshopperr

I already put a carb of a MT12 on it, It did a little better and thanks for the advice.

Striker

iTrader: (2)

My main guess is low end is lean. Second guess is air leak.

Have you checked for air leaks yet? To check, get engine up to temp. Take off airfilter. Stick finger on carb to stop air getting into engine. If it doesn't shut off right away, you have an air leak.

Have you done a pinch test yet? To check, get engine up to temp. Pinch fuel line about 2 inches from carb. Engine should shut off in about 3 to 4 seconds. Any sooner, richen bottom end. Any longer, lean bottom end.

Grasshopperr

Thanks for the advice striker I will try that.