rough idle and a miss, comes and goes?

[donimo]

Hi, the bike has been running great for over 100 miles since I did a tune up, but just today it will start to do a miss thats most noticable at small throttle opening (such as cruising in town), and the idle is about 800 instead of 1200 and stinky.

Then it will just...go away? Had it settle back while idleing twice.

I did some float adjustments and a tune up over a hundred miles ago and it has been running like a top until today.

Airl leak, fuel issue? ignition?

Im a newb.

I am searching but it seems this is a common list of symptoms for a lot of problems, so I thought I would just throw it out there, thanks!

Don

 

[Dave8338]

Hmmm...drop in RPMs joined with 'stinky'?

I'm going with a fouled plug FTW. :clap: :dancing:

 

[donimo]

a fouled plug that comes and goes multiple time a trip?

 

[Dave8338]

a fouled plug that comes and goes multiple time a trip?

Yep. It may be a coil lead that is corroded, small break in the wire, weak plug, corrosion in the plug cap, ect.

 

[tlepac]

Are all of your vacuum hoses in good condition and O rings on the Carb to engine are good? Also have you checked your timing and the condition of the points? All of the plugs look good?

Just a few thoughts.

 

[Guest]

Mine was having the same kind of miss that you are describing but gets worse the fursher I ride.

 

[donimo]

ok I will check that.


The fun of a 30 year old bike, every time I fix it I get about 4 days out of it before something totally unrelated breaks...ecchhh

Annoying only because this is my ride to work...

thanks

 

[donimo]

it seems to go away at larger throttle though, is that normal for this too? Didnt even notice it on the highway, just around town mostly...

 

[Guest]

a fouled plug that comes and goes multiple time a trip?

They're a buck fiddy dude. Aint gonna hurt to try..
Whenever anything that requires plugs starts running odd including my weedeater, my lawn mower, my trucks, my work truck, my sons truck, my wifes car, my blower, my chainsaw, my harley and even my gs, I start with new(NEW) plugs.
Did I say NEW plugs. Yeah, they should be new. Toss the old ones!

 

[donimo]

I will, these only have a month on them tops but I will go get new ones, jeez

 

[tlepac]

Caps for the coils arent that much either and a new coil wire to cap connection by snipping off a 1/4 inch or so can sometimes do wonders

 

[Guest]

Caps for the coils arent that much either and a new coil wire to cap connection by snipping off a 1/4 inch or so can sometimes do wonders

Werd!!
I say start with the cheapest/easiest then keep working yer way up the elimination process.
Unless of course ya have a crystal ball and know excactly what is is from the gittygo.

 

[SqDancerLynn1]

I would drain the float bowls see if any crap comes out, also unscrew the plug caps and cut 1/4" or so of wire off and reinstall them

 

[donimo]

I will try both, but for a newb who doesnt want to screw it up, could you elaborate on how to do the plug wire chop?

I didn't even know the caps screwed on, I thought they were all one peice, sheesh...

 

[tlepac]

What I found worked best for me was a pruning shear---Makes a really nice cut on the wire. You only need a 1/4 inch or less off the end after you have unscrewed the plug cap from the wire. Unscrewing the wire is easiest after carefully pulling the rubber protective cap off the plastic part of the plug cap. Then the wire just comes off --usual counter clockwise twist. When it comes off look at the coil wire and if it is corroded then clip back to clean copper wire. Then just screw the coil wire back on to the cap making sure to get the contact point in the center of the coil wire. When it is snug feeling then just put the protective rubber cap back on and you are good to go

Good luck

 

[tmacey45]

This too has happened to me recently. Re-built the carbs, new plugs, sync-ed carbs and bike was running flawlessly for about a week. All of a sudden, a miss at idle and lower rpm's. On the highway, I never noticed a miss at all. I took off the carbs (thinking "junk" had clogged up a pilot jet) and went through them. Nothing... As I was checking plugs and wires, one of the caps fell of in my hand... When I looked at the wire, I saw NO copper and the rubber on the end was soft, like a sponge. I trimmed off 1/4" of all 4 wires and problem disappeared. Not saying this is YOUR problem, but it sounds very close to what I just went through...Good luck!