plug fouling problem unsolved

[fabulous furry]

it has been going on for almost a year now that my 300 2009 behave badly. it is jetted lean ;PJ35 / 172 CCK needle with clip all the way up and still manage to foul a BPR 5 ES within two hours!
no it is not burning oil from gear.
and the exhaust valve is clean and working.
also it would not rev just like if a rev limiter was on.
i followed the advise from one of the forum threads and adjusted the float height still no improvement.
don't really know what to do any more it does not sound electrical because a new original 8 plug will cure the problem for a few hours only.

 

[lankydoug]

Why are you using a 5 heat range plug?

 

[Dude]

coil could collapse on extended use. 5 heat range is good for burning holes in pistons.

 

[dank]

are the plugs on the new bikes supposed to be a 5 range? i run br8 plugs in my 03?

 

[noobi]

Hes running a hotter plug( 5 ), to try and counter the fouling. Iv never heard of running a BPR plug though, I only use BR8EG plugs in my bikes.
Also what octane fuel and what 2T pre mix at what ratio are you running?

 

[johnm]

I had a rich bottom end and doing searches I came across the solutions below. The slide change worked for me, cleaned up the whole bottom end, couldn't even get it to idle for very long with a 35 pilot and air screw nearly 4 turns outs. With an 8 slide I had to increase to a 38 pilot and have the air screw at +/- 1-1/4 turns out, idles all day long

Float height
Vent lines blocked
O-rings in the jet block passing (fuel by-passes the pilot jet)
Slide changed from a 7 to 8 this cleaned up the whole bottom end, had to increase from a 35 to 38 pilot jet.

 

[fabulous furry]

I had a rich bottom end and doing searches I came across the solutions below. The slide change worked for me, cleaned up the whole bottom end, couldn't even get it to idle for very long with a 35 pilot and air screw nearly 4 turns outs. With an 8 slide I had to increase to a 38 pilot and have the air screw at +/- 1-1/4 turns out, idles all day long

i know it was a bit silly to try a 5 plug but in search of a solution..it did not even rev properly anyway.the slide is probably the last thing i did not try. the mix is good the octane is ok since i add octane booster and the base gasket is a standard .25 mm.
in the caribbean it is not easy to machine the cylinder head but i don't think it is that bad for a new bike my 250 had the original plug for 5 years and works like a champ.

 

[gasser]

Sounds like a choke issue.

 

[Tlineman]

MAybe a stupid question but are you using a BR8EG or a B8EG? Some ignitions need that resistor plug to work properly. My old YZ would foul regular B8's but I'd get all year out of a BR8.

 

[Silver]

Here is a link to my issue I had. Might help might not.
http://www.gasgasrider.org/forum/showthread.php?t=7635

 

[stainlesscycle]

Sounds like a choke issue.

+1

or cracked reeds.

 

[fabulous furry]

i will check the connections and see but the problem sounds more like carb

 

[Silver]

what do your plugs look like. if they are black and wet its carb if they are dry and sooty then it is electrical.

 

[stainlesscycle]

what do your plugs look like. if they are black and wet its carb if they are dry and sooty then it is electrical.

not necessarily.

plug could be wet and still be electrical...


but:
"also it would not rev just like if a rev limiter was on"

could be reeds, choke, jetting, or cdi...

 

[Silver]

I put new coil,wire,reeds,cleaned carb, sounded like rev limilter this is the second bike I had this issue both were cdi. issue.

 

[Bailey28]

My bike did this when the main jet in the carb unscrewed itself and fell down into the float bowl. Low and mid were great, anything past 1/2 throttle and it bogged and would not rev. I thought it was fouling the plug. Took a few minutes to find.

 

[bossmans kid]

Might sound stupid, but have you checked your compression? When rings leak a lot, you will foul plugs. If that is not the problem I would make sure the throttle slide does not leak and check for a cracked reed.

 

[socalscott]

Is your packing soaked?

If so, there may be a sloppy float pin tower hole. This allows the float to viberate sideways. Yeah, lots of fuel when rpm's pick up.

The crazy part is that I swapped a good carb from my 200(same) and it didn't resolve the issue, but a used carb body did? WTF

Bad 300, go outside now, bad.

 

[moto9]

I think the br8es pulgs are junk, try a br8eix....if you foul that one something is definetly wrong with your bike.
I have had the same plug in my bike for the past 6 months and the trails I ride are tight and nasty, so I'm rarly past 3rd gear and almost never on the pipe.
A 5 heat range plug is too hot and a 35 pj too lean...I think you got other issues going on with your scoot.

 

[Silver]

CDI I bet fixes it but what do i know only had similar issues with 2 gassers cdi fixed both.