Ok...I have an 88 quadracer...I live in southern indiana, with an fmf exhaust, uni filter, 240 main jet, clip on 2nd to top position, and 2 turns out on air screw. Running a B8/9EGV plug with 50:1 Klotz Supertechniplate oil. The thing is, when i start it, it will bog down and die. I try and restart, but it wont. I brush off the plug and it sparks again and will start. To get it warm up, i have to do this multiple times. The plug is black and wet. I know this sounds rich, but it has stock jets in it. When it finally gets warm, it will never foul a plug unless u let it cool off. It runs very strong, and never bogs or anything. Im almost scared to go any leaner, but i did take off the air box lid and it didnt help. It still does it. I really hope its a carb problem because i dont wanna get into the electrics. It has a nice big blue spark when its not fouled though. And no, im not another kid asking what jets to put in, im simply askin what i should do next. I called a local shop, and they said check float level, do plug checks, move clip position, but nothing helped. Please, i cant stand this thing right now, and i want to start racing soon. Thanks

 

Needle and seat leaking, float level, too big of a pilot jet. (stock jets may not be correct at your altitude / hmuidity level etc) choke not turning off all the way......that's the things I would check first. Is this a problem that just started or has it always done it?

 

Oh and what about the air filter....have you changed brands? Is it over oiled? I changed brand of air filter once, and it choked the airflow to the point of making it run fat at an idle.

 

One more thing. I see you run your oil at 50:1.....stock jetting is for 32:1. That extra fuel could be doing it.

 

You say you have a 240 main jet but it is my understanding that the piot jet controls idle fuel delivery. Maybe its too big, look into that.

 

You might want to try replacing the needle and the needle jet. Sometimes they wear out on these carb and cause it to run rich on the low speed circuit.

 

well...i dont think its jetting because it runs perfect after warm-up...Also, the needle and seat, and floats were replaced...The float level was also put to stock, then changed again to run a lil leaner, but didnt do anything. Called local shop and he said to check float level, make sure choke isnt sticking, replace slide needle, and also make sure low-speed needle didnt vibrate loose...gonna do that tommorrow...

 

i used to have quite a bit of trouble starting my zilla, i couldnt suss out what was wrong but i read some where that the air screw should be about 3 turns out, i adjusted it and it fired frst time, and always has since,

i only mention it because you say you turned yours out 2 turns might be worth looking into.

 

might sound stupid but have you done a compression check? low compression will cause fouled plugs also.i couldnt keep a plug in mine either then on a whim i ran a compression check and wala that was my problem not bad jetting just a well worn engine.new topend and shes on the road agian...

 

well...it still kicks over really hard...but can i check it myself? is there something i need to get from a shop to check it, because i kno the people at the local shop, and they would prolly let me use it. What is a good range for the compression? i have heard around 150 for a stock engine (which is what i have as far as i know)...thanks