Was going for a night ride a few minutes a go (still almost 90* out) , put gear on, cranked the bike, didn't start as easy as usual, but started but sounded as if a cylinder was dead, reduced choke and opened the throttle and there was a cylinder not firing. Took a short run around the block and didn't clear up any.

By now I was getting HOT and sweat starting to drip, pulled jacket and helmet off, lifted tank and verified that plug wires were all tight, they were, closed up tank. Tried to start again and no difference.

Rode the bike over 100 miles last Sunday and ran perfectly.

All I am asking is; your opinion as where to start?

Probably can't attempt to fix until later in the week.
Thanks in advance for your opinion.
Tom.....................................

 

Make sure you got a spark going through said wires.... Get a handy inline light.

 

Verify that you have no spark on that plug first (could also be the carbs if that plug is dry), then work backwards from there, checking all connections. you might want to switch the coil wires around/ spark plugs in order to check they're working properly.

Slow and methodical is the way to go.

 

How much fuel is in the tank ?
My bike runs on 3 when the fuel's low and I have to go onto reserve........
Otherwise, as Hawk has stated is the way to go

 

thanks guys, was planning to proceed as you suggested. Just wonted to check to see if anyone had had a similar experience to save some time. THANKS for the support.

 

If it's running lumpy, could be misfiring. If it still somewhat smooth I would suspect bad fuel.

These bikes run lean from the factory to get around putting EGR's and CAT's on them. The ethanol leans them out further. The ethanol separate and makes thing even worse. I ordered jets for my bike just yesterday. This fuel is getting worse and worse.

From "Rode the bike over 100 miles last Sunday and ran perfectly" to running prooly, did you fuel up? Was it your normal pump? Does it run like crap at low RPM but still scream at rev's?

If you answered yes to the above it could just be the fuel.

 

^

+1 for bad gas - had that happen a few times refueling in out of the way places

 

Just found this website. State and Province listing for non-ethonal fuel. I'm going to check it out this week. 2 stations not far from me

Ethanol-free gas stations in the U.S. and Canada



Edit: Searches in my area draw a correlation between sellers of bio-diesel and ethanol free gas.

You might try search keywords such as bio-diesel or alternative fuels

 

UPDATE: Ok had a little time and checked the spark, first checked the coils primary and secondary resistance, both almost the same and well in the normal range, then turned the engine over and had spark on all cyls.
As to the fuel, about half tank, did not fill up after ride and purchased fuel where I always do.
The engine will run and idle, but slower than usual.

Rode the bike around the block to see if maybe was a carb issue that may clear itself since nothing was really done to start the symptoms.
No change, running on three cyls. RPMs have no effect.
Today, if i have time, I plan to pul the plugs again and see if one looks different.
Initally the plugs, iridiums, all looked fine, none wet or anything unusual.

One concern is that when checking the spark, there was not much there on any cylinder, maybe because the type plug, grounding on the valve cover which has little path to ground, what ever, I've never seen the spark on this engine and they were all equal so I'm taking that as good.

Thanks for the replys, after I ck the plugs, suggestions where next.

BTW, Im not new to engines or mechanical processes in general, this issue is just bewildering do to it "just happening". Thats why I am asking the much more experienced and smarter for input

 

Throw a good spare plug in the no fire cylinder - see if it's that simple ?