Ok so i figured my bike wont start because of the plugs... but i took out the outer two plugs and they both looked fine.. the problem is i cant get to the inner two plugs... i just cant physically get to them... how do you get to yours? thanks, 98 F3

 

ok after a few trial and error things i finally just got all 4 out...
my bike wouldnt start beforeand the plugs were black, but not excessively sooty.. maybe they are, but to me they look fine. so now i am letting the cylinders air out... i charged the battery and soon i will put the plugs back in. hopefully it will start up and not backfire like it has been doing for the past two days without starting... if this doesnt work i really dontknow what else to do... thanks guys

 

put in fresh new plugs, with also if it has been sitting all winter, get the old gas out and new gas in, even the **** out of the reserve. So new gas and new spark plugs, it should help. Make sure that battery is charged also, let me know how it goes. It could have flooded from trying to start so much and now the plugs will be black like you said.I'm telling you if you took the old ones out why not put new ones in. good luck.

 

the plugs look brand new except for theblack, which i cleaned off, gas is brand new... i had it running for a long time until 2 days ago when i used seafoam on the carbs... ran it for about 5 minutes that night, wouldnt start the past two days... only backfiring when i used the choke... battery is charged to capacity... it may have flooded, but i drained the carbs from the drain screws below and then it still acted retarded... i really am stumped by this and i cant figure it out!! i even primed the carbs... (poured a little gas in the top) and still nothing...

 

I changed the plugs this fall, and the bike never got started more than 10 times or so.
It started and ran perfectly two weeks ago.
When I tried starting it yesterday, all I got was a poor attempt at running (sounded like a friggin harley!), and then it died.
I also experienced a few pops (well, more like a rifle going off) from the exhaust when I tried to restart it.
I pulled the plugs, knowing they were almost unused, cleaned them and they looked perfect.
But I never got it running on them again, today I put in brand new plugs and she fired right up.
I'd try new plugs before starting on the carbs. Actually I'd almost get a new bike before pulling the carbs again,
I found the whole procedure a pain in the rear.

 

it was the plugs... i put in autolite 4303, thats all they had... less than 2 bucks a plug. i'm gonna order some nkg iridiums though.. thanks guys i finally saw the light and you guys showed it to me... i thougth there was now way it was the plugs... but it was.. thanks

 

Lots of backfiring is usually attributed to timing, isn't it? Do your bikes have manual cam chain tensioners installed?

If so, maybe the timing was advanced because of the old hydraulic tensioner going bad... ? Does your bike ping or dog out? Worth a look, I'd think.