suzuki 1980 gs550

[johny]

good morning all 

i had a problem with the bike last year 

stationary it sounds and runs just fine but out on the road it went no faster than approx 30mph 

trying to get it to pick up loud bang backfired and blew a fuse had to push it back home 1 mile old man pushing his bike in 30 degree heat in the summer time not a good luck  

it has k&n foam air pods  i have gone 2 sizes up with the main jet 

any thoghts on this issue 

thanks john

[gs7_11]

Carry spare fuses and/or join the AA.

[wraith]

Can't see how the jetting or carbs can affect the fuse. 

Is it still on points? 

If so, are they set right and is the condenser working?