somebody correct me if i'm wrong but i think it has to do with the hemi design in the combustion chamber and with only one plug it just can't burn efficiently thats why i went to a dual plug setup and i can now run at least about 5000 miles on a set as long as i'm not just runnin around town jackin down on it alot and even then just take a long run at normal speeds and they pretty much clean themselves. just my opinion........
I haven't come across that problem yet. Bought a new set of plugs in the beginning of summer and they have been going good ever since. I'm only a beginner wrench, but I thought fouled plugs were a result of an over jetted carb. Are there other things that could cause them to foul?
the bear made the comment as in all shovel motors, that meaning all settings being as correct as they can be and yes it can simply be a carb not set properly. the kehin carb is not the best carb for all situations since if you jet it to run in the upper rpm range it will foul the plugs runnin around at say 60 mph, yet you can jet it so that it does great at 60 to 70 and runs out of gas at 90 mph or so cause the jet is too restrictive. then again a poor choice of plugs or the difference could be between runnin points or electronic ignition. the list goes on but the one thing that never changes is you still have a hemi design. don't get me wrong i love my shovels this is the third shovel motor that i have had , it's the second one in this bike. and for roger, who needs a reason , come on i'm buying the first one.
Just talked a few days ago about dual-plug-modifications to "my" mechanic. I´m ridin´ S&S-Heads on a shovel-stroker.
He said that he heared a lot of opinions about dual-plugs on a shovel. Some say it´s an improvement of starting behaviour, smoother engine work at all and a performance plus - others say that it won´t change anything at all.
So - I´m also interested to hear some opinions about that!
yep i got it, i run the dyna 2000i ing. with dual plug single fire on a 88ci s&s shovel. as far as the single fire i don't know if there is enough of a difference to worry about . what i do know is i get around 45 to 50 mpg on the freeway (70-85mph)i had never been able to get more than 40 mpg on the last motor even when it was broke in but still fresh . i usually replace the plugs at about 5 to 7 thousand miles just out of habit but they still look fine and could probably go twice as long.......keith
Thanks for that Gerry and Keith - I already have the dual plug heads but only use as single on conventional ignition - starting is my biggest challenge (S&S carb). Electronic ignition should help presumably- so it kinda makes sense to get those other plugs working as well !
regards from the UK
Apart from the dual-plug-question...I NEVER had problems with the plugs. I´m riding around 15.000 km a year and never need to change the plugs somewhere between. I´m riding Champion-plugs in an 1420ccm (86,5") stroker shovel with s&s heads, Dyna Dual-Fire & Dyna Coil.
Agree with the others......either timing, bad jettting, worn valves or rings. BTW, I'm also running dual-plug S&S heads with a Dyna single fire. I think there is SOTP improvement, and if I had more "kick" in my azz it wouldn't be so bad (I'm running 88 in. with 3 5/8 cylinders and 4 1/4 stroke). PLus they look cool.
A common problem with fouled plugs is that the carb jets at low rpms are correct but the jets at high rpms are not. The best way to set the high jet is to run the bike at 50-70 mph then turn off the engine and coast to a stop. Pull the plug and see what they tell you, then jet accordingly.
the following is for a stock-engine and it works !
Try a 295 for the idle-mixture and a 72 (or 74) for the main.
Turn the idle-mixture all the way in .
Turn it out about 1 1/2 rotations.
Minor adjustment on the idle-mixture night be needed. When I say minor it`s about a 1/4 turn or so.
Keep the idle steady by adjusting
Provided everything else is ok and you run a stock-engine THIS will work