600 iq shift backfires

[kurtjacobs]

I have a 08 600 shift. 1200 miles on it. carbs just cleaned valves cleaned. ran great in warm shop. started today let warm up backfires at idle and when riding, clears out for a bit then back at it again. Any guidance would be greatly appreciated. fresh fuel and new plugs as well. THANKS!

 

[Brock]

I have a 08 600 shift. 1200 miles on it. carbs just cleaned valves cleaned. ran great in warm shop. started today let warm up backfires at idle and when riding, clears out for a bit then back at it again. Any guidance would be greatly appreciated. fresh fuel and new plugs as well. THANKS!

Backfiring is usually a sign of being to rich.

Did you do any wfo runs and check piston wash or plugs?

Those 600’s can go down 4 jet sizes safely. Go down two on main jets and try

 

[kurtjacobs]

I have a 08 600 shift. 1200 miles on it. carbs just cleaned valves cleaned. ran great in warm shop. started today let warm up backfires at idle and when riding, clears out for a bit then back at it again. Any guidance would be greatly appreciated. fresh fuel and new plugs as well. THANKS!

 

[kurtjacobs]

Thanks. Seems more like a fuel starvation. Plugs are clean. But I will try what you mentioned

 

[Brock]

Is it stock jetting?

 

[kurtjacobs]

Is it stock jetting?

Yes it is. Only thing not stock is mbrp can because stock pipe was cracked. Ran great in warm shop. Sat outside for 3 days and now runs like crap. Thinking moisture in tank. Gonna run isopropyl thru tomorrow and see if any changes. Don't think its electric issue, but wanna isolate

 

[Brock]

Hate to say it but.

I think it’s you’re can bud?

Some cans are bad


Stock is usually best

 

[kurtjacobs]

Hate to say it but.

I think it’s you’re can bud?

Some cans are bad


Stock is usually best

I will keep ya posted! Thanks for your input. MUCH appreciated!!!

 

[kurtjacobs]

I will keep ya posted! Thanks for your input. MUCH appreciated!!!

I think I have it isolated to bad fuel.