Spark plug problem

[Shane3004]

Theres a BR8ES plug in my bike since i got, im after buyin 3 new plugs the very same numbers a ngk aswel but they dont work, it will start no bother but when i drive it on it splutters, put back in the old plug and its grand, confussed !!

[Foxx4Beaver]

what year and cc size is the bike?
it's not unheard of to end up with a new bum plug from time to time, but 3 at once is odd.
are you gapping these new plugs??

[Shane3004]

Its a 96 kx250, ya it is strange, i only rebuilt it, and dat was the plug dat was in it since i bought the bike, the gap is the same size as the old plug, she,s also spittin a lot of oil out the exhaust, if dat is the problem? Wud i need a diff plug,

[Foxx4Beaver]

what was actually "rebuilt"?...and you physically gapped the new plugs to spec?
I don't believe a "different" plug will help here....sounds like you have a rather "rich" running bike.

there can be a LOT of different reasons for it running rich..... if you rebuilt the motor, did you leak-down test it before running it?

[Shane3004]

Head was replated, piston, rings seals bearings, etc, nearly everthing but the crank!, i dident gap it to spec, i just gaped it to the old one, the jettin is 42 pilot, 162 main and the needle is on 2nd clip down from top? If dats any help,

[Foxx4Beaver]

that jetting should be good, you're on the leaner side...your pilot is actually a touch leaner than I run in my 250...the rest I run the same, but my needle is 4 steps leaner than stock also.

what was the main reason for the rebuild?
how was it running before the rebuild?
was it spitting oil out the exhaust before the rebuild?
is your float height set correctly?
filter clean and not over oiled?
how's the reeds?
what are running for a pre-mix ratio?

you never said if you did a leak-down test.

[Shane3004]

I bought the bike for a project, so i just rebuild the hole lot, i dident realy notice oil on the exhaust cause i only went for a spin around the yard, but it seemed ok, but i just rebuilt it to be sure, air filter is clean and brand new, reeds are good, not sure wat to set the float at and wat to measure off? Mixed at 32:1, when u say leak down test do u mean compression test? I dident do dat cause wit everthing new i though it be ok? It runs perferct dont have to use choke to start, the only thing i noticed was behind the air filter there was a bit of oil, kinda gold in colour, its not the 2stroke, cause the one i use is blue. Just the spitting oil and different plugs is my problem,

[Shane3004]

Also the plug does be very oily, i tink im running a bit rich, but not sure wat to change, she also gets a bit smoke when im goin easy around trees and stuff, the exhaust was just repacked aswel, thanks

[Foxx4Beaver]

does using the choke make the way it runs any different....if not, that's a problem.

a leak down test will tell you if your motor and seals are "sealing", by closing off all openings and putting 7psi of air in the motor. If it doesn't hold the 7psi then you have a leak...for instance, clutch side main seal...if this is leaking, your motor can suck tranny oil into the motor and cause an excessively rich running bike.
here's a great link how to do it.

http://oem-cycle.com/forum/viewtopic.php?f=40&t=516

I'd investigate that choke a little more first....by just getting it up to temp and pulling it on and see it changes the way it runs....it should flood it out and make it stall out.

[Foxx4Beaver]

Also the plug does be very oily, i tink im running a bit rich, but not sure wat to change, she also gets a bit smoke when im goin easy around trees and stuff, the exhaust was just repacked aswel, thanks

keep an eye on your transmission oil level...if you think it's going down, and you find yourself adding some periodically, then you may very well have a bad seal.

I'm not sure what the specs are for the float height on a 96...do you have a service manual?, that will tell and show you how....if not, get one...until then, a simple call to your local Kawie dealer should get you the specs. The best way to check it is externally....here's a link that shows what you need, it's for the 500,but it will give you the general idea.

http://oem-cycle.com/forum/viewtopic.php?f=40&t=586

[Goat]

Air filter may have too much oil on it from the oil you describe on the back of the carb. I would start there.

[Foxx4Beaver]

Theres a BR8ES plug in my bike since i got, im after buyin 3 new plugs the very same numbers a ngk aswel but they dont work, it will start no bother but when i drive it on it splutters, put back in the old plug and its grand, confussed !!

after thinking about it for a couple days...I should've had you use the "search" option at the upper left corner...type in "250 fouling plugs"...there's a boat load of info that is very much the same as your problems....the majority of it comes down to jetting being too rich. Though I wasn't fouling plugs, I had to change my needle 4 steps leaner over stock to get it to clean up...thanks to members Don46,KXcam22,BDI's posts on jetting the 250....I've got my 250 running super crisp.

Also highly recommended by the gurus was ditching the resistor spark plugs...and going to a B8ES or something similar...I run a B8EG in my 250 and 500.Going to 40:1 on the premix is also a good idea.

Click "Search"  and type in "250 fouling plugs"....a lot of good threads.

[Shane3004]

Wel sorry i was so long about getting back, i tink i have it sorted now, i changed the plug to a ngk racing BR9EG, and its not smokey any more, and no oil on exhaust, i dident get 2 go for a good spin yet only over and back the road, headin to the mountain 2moro so i,l see how it goes, do you think dat this was my problem?

[Foxx4Beaver]

Wel sorry i was so long about getting back, i tink i have it sorted now, i changed the plug to a ngk racing BR9EG, and its not smokey any more, and no oil on exhaust, i dident get 2 go for a good spin yet only over and back the road, headin to the mountain 2moro so i,l see how it goes, do you think dat this was my problem?

see how it does....two of the threads I found in the 250 section, that described the same problems you're having, ended up being an incorrect plug...sometimes what sounds like could be a complicated problem, ends up being the simplest thing.
I just found it awkward that you went through 3 of the same plugs you originally had in the bike that was running good.
Let us know how it does.

[Goat]

1 Plug heat range different shouldn't make that much difference. Running a better plug will though. I don't use B?ES's anymore. Either B?EG or B?EV also don't run resistor plugs. Definitely let us know how it runs.