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mr. softie · 02-04-2009, 08:44 PM

Alan, I had typed all this before I saw your last post so I'm postiing it anyway. If you can change a light bulb you can change a spark plug!

A spark plug that is beginning to foul will provide less than optimal performance, leading to hesitation, rough/low idle, decreased fuel economy etc. This is more immediately apparent on a single cylinder engine than on a multi perhaps. If you are adding enrichment through use of the "choke" in order to compensate for these symptoms you may be fouling the plug worse, and eventually the engine will stop running altogether. If the plug is not badly fouled it may clear up by riding at speed for a while. The plug is easy to check and would be the first thing I'd check given your bikes symptoms. Spark plugs can break down for not so obvious reasons like improper gap, a crack in the insulator, etc and that's why I suggested just throwing a new plug in it as a fist step.

Of course if the plug is looking good I would check to see you are getting a healthy spark, and that your intake connections are unrestricted and tight. Make sure the stopper plug is still in the end of the tube coming out the bottom of the airbox, and that clamps etc are tight, as any leak at all could be causing the bike to run lean (crappy idle etc.) and needing a richer mixture to compensate.

Keep us posted and let us know if you resolve the problem k?

02-04-2009, 08:44 PM	#26
mr. softie Senior Member Join Date: Jun 2008 Location: Bucks Co. PA Posts: 361	Re: Reasons for poor gas mileage? Alan, I had typed all this before I saw your last post so I'm postiing it anyway. If you can change a light bulb you can change a spark plug! A spark plug that is beginning to foul will provide less than optimal performance, leading to hesitation, rough/low idle, decreased fuel economy etc. This is more immediately apparent on a single cylinder engine than on a multi perhaps. If you are adding enrichment through use of the "choke" in order to compensate for these symptoms you may be fouling the plug worse, and eventually the engine will stop running altogether. If the plug is not badly fouled it may clear up by riding at speed for a while. The plug is easy to check and would be the first thing I'd check given your bikes symptoms. Spark plugs can break down for not so obvious reasons like improper gap, a crack in the insulator, etc and that's why I suggested just throwing a new plug in it as a fist step. Of course if the plug is looking good I would check to see you are getting a healthy spark, and that your intake connections are unrestricted and tight. Make sure the stopper plug is still in the end of the tube coming out the bottom of the airbox, and that clamps etc are tight, as any leak at all could be causing the bike to run lean (crappy idle etc.) and needing a richer mixture to compensate. Keep us posted and let us know if you resolve the problem k? __________________ The real money in a gold rush is in supplying liqueur and women to the miners.... May the wind always be at your back and the sun overhead as you make your way down the ever winding, smoothly paved, traffic free road!
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