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Fouled Spark Plug(s) on the 505 any ideas???

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OK - So the bike (07 SXF 505) had a fouled plug that was super black and when I replaced it the bike was running like a champ only to make it 5 miles down the road and than another plug fouled again just as black.

So I am thinking I am running really rich on my jetting (carb is stock) but was also wondering if the map ignition switch I installed is causing my bike timming to smoke the plug. I am hoping it is nothing more than that. The bike has less than 5 hours on it

Has anyone had or heard of this problem and what they did to fix it?

Thanks

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doesn't sound like the problem exactly but did have a buddy o a honda last year where it would act inconsistant then just die and never start, his kill switch was shorting out. Might be worth unhooking to check but again doesn't sound like it's that simple. Sorry and good luck.

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OK - So the bike (07 SXF 505) had a fouled plug that was super black and when I replaced it the bike was running like a champ only to make it 5 miles down the road and than another plug fouled again just as black.

So I am thinking I am running really rich on my jetting (carb is stock) but was also wondering if the map ignition switch I installed is causing my bike timming to smoke the plug. I am hoping it is nothing more than that. The bike has less than 5 hours on it

Has anyone had or heard of this problem and what they did to fix it?

Thanks

Have you tried running the map switch at the stock position (aggressive curve). I would try that and see if the plug fouls. If it doesn't you may possibly be running on the threshold of rich and the retarding of the timing on the soft setting could richen it excessively... Never heard of it before tho... just brainstorming. Rare that a four stroke fouls plugs.

If the carb is stock jetting that should rule out temperature conditions. We regularly see close to freezing to +30c in a days ride and the stock jetting worked (barely) for me at that much of a temperature swing...

**scratches head**

Any elevation changes since it started acting wierd? Had it sat over the winter and is this your first ride of the season? or did you put the 5 hours on it this spring?

You might want to also try posting in the jetting forum...they're pretty knowledgable over there...

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OK - So the bike (07 SXF 505) had a fouled plug that was super black and when I replaced it the bike was running like a champ only to make it 5 miles down the road and than another plug fouled again just as black.

So I am thinking I am running really rich on my jetting (carb is stock) but was also wondering if the map ignition switch I installed is causing my bike timming to smoke the plug. I am hoping it is nothing more than that. The bike has less than 5 hours on it

Has anyone had or heard of this problem and what they did to fix it?

Thanks

Check with f2racing.net they have the solution. They actually change to a different sparkplug and it not only solves the problem but gives better throttle response and more power from the bottom up! They will fill you in on all of the details or go to their website they have the explanations on video you can download!

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Check with f2racing.net they have the solution. They actually change to a different sparkplug and it not only solves the problem but gives better throttle response and more power from the bottom up! They will fill you in on all of the details or go to their website they have the explanations on video you can download!

I see you have an 08 505 xcf, did you switch to the different plug on your 505 and if so what differences did you notice? Thanks

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Have you tried running the map switch at the stock position (aggressive curve). I would try that and see if the plug fouls. If it doesn't you may possibly be running on the threshold of rich and the retarding of the timing on the soft setting could richen it excessively... Never heard of it before tho... just brainstorming. Rare that a four stroke fouls plugs.

If the carb is stock jetting that should rule out temperature conditions. We regularly see close to freezing to +30c in a days ride and the stock jetting worked (barely) for me at that much of a temperature swing...

**scratches head**

Any elevation changes since it started acting wierd? Had it sat over the winter and is this your first ride of the season? or did you put the 5 hours on it this spring?

You might want to also try posting in the jetting forum...they're pretty knowledgable over there...

Hey Thanks I will try switching the curve and I think your right on the bike being rich. I put the JD Jetting kit in it today (haven't had the chance to start the bike and run it) and the bike had a 185 main with a 145 idle Jet and the part of ALaska I ride in is at 250ft above sea level. So I went with the gets recommendation of 182 (3 clip from the top) and a 140 idle jet. I also just installed my R&D Racing Bowl. So hopefully that will do the trick.

And my riding was in the spring time of last year and the bike did sit all winter long in the garage. But I did change everything out before I took it out for a ride.

I'll keep you guys posted and thanks for the help

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I was going to suggest the jet kit and bowl but you beet me to it, I worked on a 505 sx and it wouldnt hardly run until I did the carb mods. Make sure you check the float level while you are in there. The spark plug helped burn the extra fuel due to a hotter plug and its a much better plug to begin with. I recomend going to the irridium plug if anyone has their tank off.

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I was going to suggest the jet kit and bowl but you beet me to it, I worked on a 505 sx and it wouldnt hardly run until I did the carb mods. Make sure you check the float level while you are in there. The spark plug helped burn the extra fuel due to a hotter plug and its a much better plug to begin with. I recomend going to the irridium plug if anyone has their tank off.

Yeah I made I tried starting it and no luck. The spark plug had a solid fire to it. I hit the magice button only to get the bike to crank but not fire up (not even a little bit). So I am gonig to go back threw the carb and see if there is anything dirty or clogged. The float check what do you do for that because I normally just check to ensure they move freely? Would running a smaller ideal jet cause the bike not to fire at all? (I know these questions should be in the Jet form).

Thanks

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Put the JD kit on. Change the idle jet back to #42 . It should be in the Ballpark right there.

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Put the JD kit on. Change the idle jet back to #42 . It should be in the Ballpark right there.

Well give it a shoot thanks Ville. Keep you guys posted

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Variations in jetting from stock is a fine tuning thing, you have something wrong! I would avoid adding accelerator pump gimics etc until we find what it is that is wrong.

FOr starters, remove the spark plug, hold the kill button in and spin the starter to pump any gas out, next drain the oil out of the engine into a clean pan, then carry the pan out of the garage away from anything mechanical and smell it, is it saturated with gas?

If so replace it, if not put it back in, spray some WD40 in the plug hole, hold the kill button and again spin the engine, object is IF gas had been leaking into the cylinder it would not be unheard of for the oil to be washed off the cylinder wall to the point that the rings will not seal. Then with a fresh dry plug try the startup porcess over

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