80 kz750 ltd runs terrible after 10 miles

1980 kz750 ltd 4, electronic ignition. Runs ten miles parked for an hour parked then runs horrible. Thursday I had to get it towed it seems like the 1-4 plugs were not getting any spark when I tested it the next day and now it is, it likes to buck when starting from a standstill. It does good after 3500 rpms all the time until now. Also has some serious fireballs from the exhaust. The valves seem to be in order, .08 (give or take a 0)or less. When it broke down the oil was really low. Any serious helpful help is seriously appreciated.

Sounds like you need new coils.

When coils get hot they expand. There may be breaks in the windings, the breaks in the coils make
contact when cold. But as the coils warm up and expand the breaks lose contact. I have seen this
with many old bikes. It is very difficult to check a coil with this problem.

oh great that's kinda what i had in mind, i don't think i can go around saying i told you so on this one because i didn't tell anyone about this, thank you for your help.

www.z1enterprises.com sells the Emgo coils along with the pricey Dyna coils. Another popular replacement is the Yellow 3 ohm Accel ignition coil.

i also think a carburejet would be in order, i have a k&n drop in filter and a free flowing exhaust and i don't want to burn up my internal organs on the engine. i have polished the cooling fins for the most part on the engine, and already it runs better.

I had a simialr problem. Bike would start great everytime, but after it warmed up it ran like crap. Tested the coil (cool) and it was fine. I tested it warm one day and boom, found the problem. A new Dyna coil later and all is good, untill the more recent problem . Thats for a different forum though.

Swap your coils, one side for the other. If the problem shifts to the other two cylinders, you know you have a bad coil that is faulting intermittently. If the problem remains on the original two cylinders, you know it is not the coil.

At that point my educated guess is you have a defective ignition pickup. (This has happened to me.) Swap another one in, and you will likely fix the problem.

Of course, make sure your connections and wiring are all good in the ignition circuits.

i got it now i found a loose wire from when i put my hei modules on the bike.

donthaveakawman wrote: i got it now i found a loose wire from when i put my hei modules on the bike.

has anyone ever popped a wheelie on one of these?

donthaveakawman wrote:

donthaveakawman wrote: i got it now i found a loose wire from when i put my hei modules on the bike.

has anyone ever popped a wheelie on one of these?

only on you tube.

Reminds me of the old joke:

What's a redneck's last words?


HEY! WATCH THIS!


An equally correct answer is:

SOMEBODY HOLD MY BEER....