What would cause this? The plugs look ok. I checked the wires. I know each of those cylinders is controlled by a different coil so it couldnt be the coils right? If both coils were bad none of the cylinders would fire, right? Thanks for any help.

 

Dealt with a problem like this for the past year pulling my hair out trying to fix it. After carb cleaning (numerous times), and a carb sync, finally seems to have fixed problem. I replaced coils, wiring harness, and plugs and still couldn't fix it. Finally just took Hershey's advice and cleaned, cleaned and cleaned carbs, then sync'd them. Maybe this might work for you. The easiest way to tell was to check temperatures on the headers and look for the cold one. I use a laser temp gauge. Well good luck to you. I really hope you post your findings and your solution!

 

Before spending the time and money on mechanical carb cleaning. Try "Sea Foam" its a fuel system and engine cleaner that's been around sense the 1940's. I've used it on my boat motors, my 1978 GMC Truck, my 2004 chevy Silverado, and my 94 CBR600. It makes a BIG difference every time I use it, and has saved my tons of cash and time under the hood. If it doesn't work then you'll have to go the mechanical cleaning route. The stuff comes in a white metal can with the name "Sea Foam" on it. It wont hurt the engine at all, and may save you time and money.

 

That's exactly how I checked them, by finding the cold header tubes. I used my finger though haha. I have never messed with a carb before So I hope thats not it. The bike has a lot of miles on it so I'm going to go ahead and replace the plugs, wires and coils and see if that helps. I know all about seafoam, good stuff. I've used it in a lot of my cars. I'll give it a shot, can't hurt.

 

havin the same problem ut only on 1 got worse after the rain over the weekend so im going with a dgraded wire cause i got fire and gas thinking its just not a hot enough spark

 

Post an update when you get one. Looking to see what the solution is. Good luck!

 

I will. I haven't really messed with it yet. I think I'm gonna clean the carbs real good today and see if that does anything. It's probably never been done before seeing how the previous owner didn't even know it was missing 2 cylinders haha. 49,000 miles, I would say it's overdue.

 

Got the carbs off and apart today. They didn't look too bad. Looks like there's a jet kit put in it because there's a little washer/shim around that jet needle or whatever it's called (The bike has an exhaust and K&N filter). The c-clip is in the second groove from the top. Not really sure if thats where it belongs. I need to get new screws for the float bowl covers because whoever was in there before rounded the hell out of them. I took a little cut off wheel and turned them into flatheads so I could get them off. I'm picking up a parts bike this weekend so I'll prob use those screws if thery're not bad also. The parts bike has less miles so I'll prob swap the coils and wires to just to see if that helps. I'll keep u guys updated.

 

definatly been jetted then as for clip position its trial and error check the thread on here for other ppls setups. my carbs ddint look bad either but pilot jets were pretty gummed used a strand of eletrical wire and carb cleaner to get them clean.

 

Hope that parts buike came through. I keep checking back for an update to see if you got it pinned down.