Foul'd plug help

desgre90

Member
Jun 26, 2009
219
4
49
As most of you know, I just rebuilt basically my whole blaster. Broke in my motor I finished rebuilding two weeks ago. Haven't really had it out lately now that it is back (don't want to break it :p) but yeah I had it out this morning, she started alright but as soon as you gave it any throttle she wanted to spit and sputter. Pulled the plug to find it all black, oily, and deposits around the outter bottom ring of the plug. Motor hasn't even had 4gal of gas run through it yet because my gas can still has some in it. I was going to take a picture of the plug to post it... but I think we have all seen a fouled plug before I:I

Some useful info...

I am premixing Amsoil Dominator 2cycle at 32:1 like everyone else does on here although the company recommends 50:1.

FMF Stage 2 jetting. E clip in #3 position (middle). 360 main jet. Air screw turned out 2 full turns. This is supposed to be for an FMF exhaust, stock / aftermarket reeds, and airbox lid removed. I modified my airbox lid to use a pre-filter. (reference this thread if you missed it)

http://www.blasterforum.com/engine-13/ehs-airbox-lid-anyone-ever-used-29130/

I was using a BR8ES, but swapped a BR9ES today because I had a new one on the shelf in the basement. The new plug fixed the problem, but obviously I want to fix the "real" problem.

Thanks in advance,
Greg
 
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i dont think its that high , i have less mods than him and i run a 300 and mines pretty much dead on....id say try a 340 n then a 320 if its still to fat.....
 
the fmf jet kit comes with a different needle too, forgot to mention that. I'll look in the box of jets and see what I have on hand. I figured I could drop the main, but if I needed a needle position change, I wouldn't know when to do it. Thing of it is... she runs like a champ! I guess she is just loading up at lower rpms / idle.

Edit

I have 210,220,230,350,360

Maybe ill swap to the 350 for now, and order some more jets
 
id say drop the needle one and see how she runs like that...if its still loadin up id drop down toa 340, then like i said a 320 if its not better.....but dont do the need and the jet at the same time, cause then you wont kno which one fixed it obvioulsy.....
 
that main jet is huuuge, when i had a stock stroke and no porting i was at 300 with a powerpros pipe reeds and no lid.

Not sure im following you noober... you say it is huge (which we all understand at this point), but you say your at 300 with stock stroke and no porting. I'm +4 stroke and porting. What number should I be at then?

I hear awk is good with jetting, hopefully he can chime in :)
 
Stock carb I take it. On a ported and stroked motor- 360 sounds good to me. Have ya done a air leak test after ya put the reed cage on? I know alot of people are sick of hearing this but i really think it's one of the most important things to do before you fire it up. Could save ya the 5-8 hundred dollar engine work ya just paid. If ya have the carb off stick your finger into the reed cage and see if it's moving around (loose) my was and caused similar issues but would scream at WOT. Also see what size slow jet (pilot jet) your using that is what idle to 1/4 throttle uses, May need to step that up.

I also remember someone talking about the amsoil that 32:1 doesn't work for that oil brand ? Damn can remeber who it was...
 
i bet its your pilot jet is your problem if its stock. Also, those jet kit sizes are messed up, not even close to what they should be called, mine sounds rich to, but it aint
 
mine says 350, and my bike is pretty close to stock, that was dynojet though. Also, the br9 plug doesn't make sense to me. that is a colder running plug, at least thats what i thought, don't know how that makes it better
 
mine says 350, and my bike is pretty close to stock, that was dynojet though. Also, the br9 plug doesn't make sense to me. that is a colder running plug, at least thats what i thought, don't know how that makes it better

airleak covered up with fat jetting, and the 8 makes it run to hot? how cold is it in Ontario, CN?
 
Not sure im following you noober... you say it is huge (which we all understand at this point), but you say your at 300 with stock stroke and no porting. I'm +4 stroke and porting. What number should I be at then?

I hear awk is good with jetting, hopefully he can chime in :)

hahaha whoops!! didnt look at your mod list, saw stock carb and assumed a semi stock bike :-[ :-[. in that case 350 does not sound unreasonable to me at all, mabey even a little lean.. weird how the plug is all black.
 
mine says 350, and my bike is pretty close to stock, that was dynojet though. Also, the br9 plug doesn't make sense to me. that is a colder running plug, at least thats what i thought, don't know how that makes it better

It ripped fine with the br8es when i broke the quad in. the plug fouled and so i tossed the br9es (what I had on hand) in and she still rips around great. Same perf, just it runs with the 9 because its not fouled. Is my temp fix because I know it is going to do it again.
 
airleak covered up with fat jetting, and the 8 makes it run to hot? how cold is it in Ontario, CN?

haha, i don't have an air leak, ran fine stock, just put that in cause i took the airbox lid off and put a k&n in. I just got a jet kit cause i was at a place and thats all they had and i was lazy, jet kits are nowhere near the actual size, so as far as i am concerned it isn't leaking. And for the temperature up in igloo country it has be over 90 degrees up here for two weeks
 
and no, the br8 is a hotter running plug then the br9, least that is what i have been told, the br8 is stock, thats why i was wondering how a cooler plug didn't foul, but a hotter plug did
 
I also remember someone talking about the amsoil that 32:1 doesn't work for that oil brand ? Damn can remeber who it was...

Damn... just bought a gallon of it X( I'll go buy a bottle of regular 2cycle oil I guess and see what happens. Maybe that will become be the new weed eater mix lol. Then again... if it is that dirty, not sure I want it in there either.
 
amsoil is good oil, have u tried mixing it at different ratios? i mix quicksilver at 40-1 in the blaster and i know in my jet ski i mix 50-1 hell some outboard motors call for 100-1

so u might try that then report back
 
amsoil is good oil, have u tried mixing it at different ratios? i mix quicksilver at 40-1 in the blaster and i know in my jet ski i mix 50-1 hell some outboard motors call for 100-1

so u might try that then report back

I'd rather just get another bottle of something else and mix 32:1 instead of risking mixing too thin if amsoil is indeed the problem. Im going to try that first... whenever i get around to it.