Fouling plugs?

[TavisB]

I just fouled a brand new plug (well, maybe 4 hours on it) on my 03 EC250. This is the second time this has happened. I had just started it (first kick too) and was warming it up. It sounded fine then I think under slight throttle (I was revving it just a bit) it just died and wouldn't restart. Put in a new plug and fired right back up and ran fine.

Here's the plug after I pulled it:



When I started it I left it on full choke for about 10 seconds and then 1/2 choke for another 5 seconds or so. Then I took the choke off and just gave it a few revs here and there to keep it from dying. I didn't rev it high (maybe I should?).

Pilot jet is a 38 and main is a 172. Slide and needle are stock. It takes a while to warm up and if I had to guess I'd say it may be running a bit rich.

This is my first 2T in quite a while, and I've never had to mess with the jetting on one (but I have on my DRZ so at least understand the basics).

So...where do I start? Is this a jetting issue, or my noobishness?

[GasGas]

I would say your needle is rich. Some good info here http://www.gasgasrider.org/forum/showthread.php?t=12253

And here
http://www.gasgasrider.org/forum/showthread.php?t=12005

[gasmonkey]

Fresh high quality gas??
Biff that poxy oem needle.N1ee,n1ef are just too rich.
A suzuki nedw needle will get it in the ballpark for jetting,or a jd blue.
Heaps of info on here about this, curtisy of jackobi and pals

[TavisB]

Originally Posted by gasmonkey

Fresh high quality gas??
Biff that poxy oem needle.N1ee,n1ef are just too rich.
A suzuki nedw needle will get it in the ballpark for jetting,or a jd blue.
Heaps of info on here about this, curtisy of jackobi and pals

Gas was two months old. I'll look into the needles, thanks!

[TavisB]

I did a better inspection of the carb this week and found that my floats were broken. There was a crack in one of the metal arms. I'm hoping that was the source of my problem.

[Jakobi]

I've also found the BR8ES/BR8EG is a bit more resistant to fouling than the small tip of the BR8EIX.

[TavisB]

I wanted to give an update. Even after fixing the float I was still fouling plugs. Took it into a local shop, and they confirmed that my jetting was correct. They swapped out the stator for a new one and it seems to be running much better. I only have one full day of riding on it since I got it back, but it seems much better and hopefully it is indeed fixed.

[motorhead]

Originally Posted by Jakobi

I've also found the BR8ES/BR8EG is a bit more resistant to fouling than the small tip of the BR8EIX.

Agreed on the es,never had much luck with more expensive "race" eg.
I have been using bpr8es for years,theory has it projected tip is more foul resistant. I wouldn't run one if your head has been milled or squish reshaped.

[Jakobi]

Originally Posted by motorhead

Agreed on the es,never had much luck with more expensive "race" eg.
I have been using bpr8es for years,theory has it projected tip is more foul resistant. I wouldn't run one if your head has been milled or squish reshaped.

The BR8ES has a non-projected firing end. Meaning that the insulator does not project above the metal shell is looking at it from a side profile.

The BPR8ES has a projected firing end, so it will project farther into the combustion chamber. From the side you would actually be able to see the insulator sticking above the shell.

So the BRP8ES projects further into the cylinder head. This means there is a very real possibility it would physically hit the piston when the piston is at TDC. This risk rises if compression has been raised.

I learnt something new today. I figure I can go through 3 x BR8ES plugs for the same price as one BR8EIX. But in saying that I've never had an issue with an ES fouling/failing.

[motorhead]

Originally Posted by Jakobi

The BPR8ES has a projected firing end, so it will project farther into the combustion chamber. From the side you would actually be able to see the insulator sticking above the shell.

So the BRP8ES projects further into the cylinder head. This means there is a very real possibility it would physically hit the piston when the piston is at TDC. This risk rises if compression has been raised.

As stated in my above post
I would NOT recommend the "P" version if you have had your squish reshaped or are running an aftermarket head or your head milled for higher compression.

A "celebrity" tuner years ago told me about the projected tips after consulting him regarding my kx500's appetite of consuming spark plugs,thought it was ironic that when I ordered his suggested carb slide from carb parts warehouse that they suggested the exact same plug.