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post #1 of (permalink) Old 10-29-2008, 09:14 PM
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Honda 400 EX backfires

I have a 1999 400EX that is hard to start and backfires when warming up, and backfires when I let off the gas after it is warmed up. It also has trouble idling.

Any ideas?
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post #2 of (permalink) Old 11-01-2008, 11:05 AM
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there are 2 things
u may have an exhaust leak causeing it to run lean (which causes poping)
check for ehause cracks or loose bolts

but mainly your promblem i think is ur piolet jet is a little clogged (its the jet for idleing) and sence its clogged a little, not as much gas can get threw threre for makeing in run lean (low on gas in the gas air mixture)

pull the float bowl off (bottom of the carb) and there are 2 jets 1 sticks way out and one kinda hides back in a tube

use a flat head screw driver to pull the hideing jet out and spray it out with carb cleaner for a while and even blow threw it with an air compresser

put it back in and that will fix your problem

i highly dought its the exhaust

Last edited by Mr_RPM; 11-01-2008 at 11:08 AM.
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post #3 of (permalink) Old 11-21-2008, 08:58 PM
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x2 on the pilot jet
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