Need some advice. Changed the exhaust and intake on my 07' Dyna. V&amp\\;H HS slip-on's, FuelPak and K&amp\\;N RK3910 High Flow Kit. The bike pops and backfires on decel. I did run the bike with the pipes and fuel pak for approx 500 miles before changeing the intake. This may have caused a rich fuel condidtion. I pulled the plugs and they have a powdery white appearance. Per the HD manual, white is acceptable (no mention of powdery). In my experience, a plug from and engine running the correct air/fule mixture should have a nice tan or carmel color. White was always a sign of being too lean or too hot. Any suggestions?
Gonna by a new set of plugs today and see if that makes a difference.

 

I'm sure an Expert will have the real scoop but&nbsp\\;I wouldn't worry about a white electrode on plugs anymore because&nbsp\\;many all the gas additives out there will cause what was tradionally called a lean look. I would worry only&nbsp\\;if the inner steel wall between the electrodes and threads of the plug is white. The backfiring can be caused by a leak in the intake or exhaust and since you recently did some intake work I would check that first.

 

light tan good,, white, bad.....&nbsp\\; got to be running a bit lean and hot there i reckon...

 

I am an old mechanic and am slowly getting used to white plugs.&nbsp\\; I guess the new fuel burns cleaner.&nbsp\\; Mine are a powdery white with a slight gray tint.&nbsp\\; It is those bleached white glazed with black spots that isn't good.&nbsp\\; Reading plugs just isn't what it used to be.

 

I am experiencing a popping and occasional backfire on decelleration. I have the Vance and Hines slip on mufflers, Vance and Hines Fuel Pak and K and N RK3910 high flow kit. I will pull everything tonight and
re-install and replace the spark plugs at the same time. If I have a leak at the head pipe / muffler joint does anyone think that would cause the popping and backfire?

 

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YES!!!!!

 

I heard covering slip ons connection with High Heat gasket silicone to avoid any air from outside getting in.

 

HDDDyna, Some of the copper fortified stuff might do the trick....

 

If you dont have an exhaust leak, then the bike is lean in the zero throttle position.&nbsp\\; Richening it up a bit in that range will eliminate the popping on decel.
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White to a slight gray condition is pretty much normal anymore, unless as others said, you have&nbsp\\; black spots as that is an indication of detonation.&nbsp\\; If the whole plug, electrode, insulator is white, then again, you are a bit lean.