[turdferguson]

Hi all, yeah i know it's a lot, hang with me!.......

It's a '95 Kat 750...600 block bored out, everything else on bike is for a 600, anyways.....Air filter is good and plugs are OK, carbs have been rejetted and it has yoshimura headers and can.
Couple days ago bike started runnin like crap...rough idle and had a noticeable sputter or miss that increased in frequency with the rpms....then SEEMED to smooth out at 4 or 5k rpm, also the bike is not smoking. I suspected bad gas, I had filled up earlier that day, so I drained it and put fresh fuel in with no change. One thing to note, after starting and allowing to idle, the 1,2, and 4 headers got HOT quick, while I could still almost touch 3 for a split second.
I ran it for a bit with the tank off, then quickly pulled the plugs. Plugs 1, 2, and 4 had raw fuel on them. 1 and 4 share a coil, and 2 and 3 share another. I looked in on the coils where the wire connects, wire looked nearly rusty, as was the needle that stabs the wire on each of the misfiring plugs. #3 looked good.
I cut the wires back for a fresh connection, and scraped the needles as best I could, no change.
The oil level has not changed, battery is 100%, and fuel lines are not plugged. The unknowns are if it's the carbs, or the ignition. Up until this, the plugs have been very consistent in thier wear and condition, and this was not progressive, showed up one evening.
I'm running up to WallyWorld for a cheap spark tester thingy to see if the ignition is OK, it's only a couple bucks, might as well try.
I tried to be as thorough as possible, but I've run out of ideas!
Also I would think that the misfiring cylinders would be cooler?
Thanks for any ideas....
Dennis

 

[Dave2122]

These bikes had a tendency to have coils go bad on them. Just like the early 86 thru 89 GSXR's. If you test the coils and they are ok I would check all your electrical connections for corrosion. If that checks out then look into the carbs for dirt. Also check your needle vlaves for propper operation.

 

[turdferguson]

Well my little tester thingy showed that all plugs were firing, so I pulled the carbs. Pretty much throughout the carbs and bowls was a thin oily looking film, that released as soon as the carb cleaner touched it. Each bowl had grit on the bottom. I pulled the jet needles out and pretty much cleaned everything I could without actually unscrewing the jets. I did not stick anything through them, but shot carb cleaner through and now everything's shiny and clean.
I'm gonna put them together and throw them on the bike, hopefully that solves the problem. Regardless if it fixes it, they sure looked like they needed it anyway. Hopefully I didn't go too crazy with the carb cleaner, but I did spray a little into where you can see the valves, and it pretty much liquified any oily deposits that I saw. I imagine it'll burn that stuff off when I get this thing firing again. Take care,
Dennis

 

[turdferguson]

Ok carb is back on and same problem. It doesn't lug as bad so cleaning the carb did help, but that's not what's goin on. Does ANYONE have ANY IDEAS, before it goes to a shop. I need this for transportation. Same thing, 1,2 and 4 header pipes got hella hot, while the 3 was hot yet noticeably cooler. ANY ideas........