[culvert]

01' 450
Bike is all stock. I have cleaned carbs and set clip 1 postion higher. Dropping the needle. Found the bike has more snap off the line and higher top end than before but now I have backfiring.

Always when letting off throttle. Did it mostly when coasting down steep hills in lower gears, high rpms.
Can I cure this with a fuel mixture adj.(richen or leaner) or do I need to put clip back to stock.

Sure has some good snap and pick-up now. Maybe that is just the clean carb?

Thanks for any help.

 

[dirty4man]

moving the clip up to drop the needle will lean the bike out on the top end. that is why it is poping on decel.
See what your plug looks like, white you are runnig lean and black is rich. Tan color is what you want. Running it lean will make the bike run hot and damage the piston and rings.
I would move it back to factory setting. adjusting the air-fuel mixture will not help enough to make a difference. IMO

 

[culvert]

thanks, I'll put it back to stock.