Went riding last weekend on the good 'ol KDX220 with my riding buddy ('01 YZ125, don't even ask me how it does the tight woods riding on this thing... he let me try her out the other day, I'm still trying to find some bottom on that bike.) and his wife. Bad idea, the wife. She has a TTR125L, which actually rips for what it is, but she goes about as slow as humanly possible without coming to a dead stop. Needless to say, the two twostrokes were in danger of plug fouling on such an insanely slow ride. I didn't foul a single plug all season, but I finally did that day. It was weird, it ran in a semi-fouled state for quite a while, before quiting completely. We replaced my fouled plug with a BR9ES, and it fouled that almost imediatly. Is that because of the heat range difference? I couldn't believe it fouled that fast, so I'm a little worried. I haven't started it since it fouled that plug, I'm in need of a trip to napa. But could that heatrange being off by one number cause it to foul so quickly? Anybody else have a simialar experience?
Fouled Plugs (what a PAIN!)
- Thread starter atc3434`
- Start date
yeppers, I love my KDX for the put-put-ability but behind my kids with a BR9 plug I can foul them as fast as I used to on my RM. I'm currently running the '7' and it works much better. I have 8's too and use them on hotter faster days, but won't buy anymore 9's
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Thanks fella's, I'm sure it was just going to an even colder plug that caused my problems, thanks for your input, I'll have to consider going to a BR7ES, although I think the eight was hot enough, it the first time it fouled all season, so that was pretty impressive i thought. Another thing I learned that helps with fouling plugs is good gas. My buddy and I mix up to an octane of like 100 - 105, and they just don't foul, where as with 87 - 94, they are much more likely too. Makes the bike nice and fast!
I used to foul alot of regular 8's. Drilled the airbox and moved my needle one position leaner to help. Didn't help fouling. Switched to a BR7ES and it never fouled but looked slightly lean. I have since found the perfect plug for my bike with a BR8EG. Yeah...the "EG" racing series! Perfect color and I don't risk being lean with the 7. And have had the same plug since last spring with no probs. Give it a whirl.
David Trustrum
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- Jan 25, 2001
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Um, the real slow running will be controlled by the pilot jet as well, possibly quite a bit. At low throttle openings & revs there is little suction so the airbox will not be a restriction.
Ignore what the plug looks like, this isn’t road racing where you can say it was WFO throttle for 20 seconds, besides that would only tell you about the mainjet.
Ignore what the plug looks like, this isn’t road racing where you can say it was WFO throttle for 20 seconds, besides that would only tell you about the mainjet.
Try the BR8EG or BR8EVX. The EG and the EVX both have very fine electrodes. The fine wire plugs can help reduce fouling since the spark is condensed when making contact with the plug end. I've used the EG's and EVX's for years and they do help when putting around at low speeds. Jetting is very important also. This info came from the NGK tech rep.
