#4 Cylinder Dead - Can't find Cause

[SocialAnomaly99]

Nice! Glad to hear it!

 

[barnbiketom]

awesome! I've had a number of carbs stay dry after a refresh.. dunno why it happens but it does... once they get gas , all is well!!
CONGRATS.. hope the valves are right on baby!!

 

[Guest]

Hey guys, in an attempt to stir up an old thread I'm having basically the same issues with #4 cylinder except that regardless of which boot I use #1 or #4 it does the same thing. With the boot fully on #4 doesnt fire, if I pull the boot off and just place it on top of the spark plug the cylinder starts to fire! It's almost like something is shorting out my ignition coil??? Any thoughts?

 

[Rich82GS750TZ]

Spitballing hear based on what I’ve read. Bike originally had resistor caps (I think). Original spark plugs were non-resistor. If you’ve replaced plugs with the more commonly available these days resistor type, you could have 1 too many resistor on a given line?

 

[Guest]

Spitballing hear based on what I?ve read. Bike originally had resistor caps (I think). Original spark plugs were non-resistor. If you?ve replaced plugs with the more commonly available these days resistor type, you could have 1 too many resistor on a given line?

I'm not sure if i follow you...So a little background, the bike had the original ignition coils on when i got it, which i have had issues with over the last 2 years. So last year i did the coil relay mod and now get a full 12v to the coils. Then a couple weeks ago i picked up a new set of coils off amazon, i know someone is going to give me grief about it but yes they are cheapies from china...although it doesnt seem like its a coil issue, as yesterday i went ahead and swapped the 1-4 coil back to the original and it does the exact same thing! I'm very confused how that could even happen unless its a spark plug issue, is that what your referring too @Rich82GS750TZ ?

 

[Rich82GS750TZ]

Sorry, I have very limited knowledge on this, just something struck me about your issue that made me think of reading about spark plugs, caps, and wires, any of the 3 can have resistors, but you only want it in one of the three, and that could potentially be an issue for you. It may not be. Just thought it was worth exploring the idea. Take a look at this thread, the knowledgeable people like Nessism and Steve know what they're talking about. See if any of that info seems to make sense with your issue.

You may want to start your own thread on this.

Tip on using this sites search function.
Always used advanced
Type in your keyword(s) and change to search titles only. It's the only way to get any meaningful results.
Good luck.

 

[Guest]

Sorry, I have very limited knowledge on this, just something struck me about your issue that made me think of reading about spark plugs, caps, and wires, any of the 3 can have resistors, but you only want it in one of the three, and that could potentially be an issue for you. It may not be. Just thought it was worth exploring the idea. Take a look at this thread, the knowledgeable people like Nessism and Steve know what they're talking about. See if any of that info seems to make sense with your issue.

You may want to start your own thread on this.

Tip on using this sites search function.
Always used advanced
Type in your keyword(s) and change to search titles only. It's the only way to get any meaningful results.
Good luck.

Thanks for the info! I'll try to dive further into this!

 

[Brendan W]

Hey guys, in an attempt to stir up an old thread I'm having basically the same issues with #4 cylinder except that regardless of which boot I use #1 or #4 it does the same thing. With the boot fully on #4 doesnt fire, if I pull the boot off and just place it on top of the spark plug the cylinder starts to fire! It's almost like something is shorting out my ignition coil??? Any thoughts?

Run it in the dark with the boot in both positions. You are looking for spark escaping from the boot to the cylinder head.