Topic: Resistor Plugs w/Resistor Boots???

[TommyT]

OK so I got my K8 back together and running but it's not running that good at all.  #4 cylinder is really cold on exhaust pipe and not firing.  It has spark but isn't running good.  So i check the plugs and they are a DPR8EA  and it has the NGK 5K Ohm caps on it.  What kind of symptoms would this cause.  Could it be the cause of my weak spark and cold plugs???  If not any ideas what it could be.  any and all help is appreciated. 

[phil71]

how did you come to decide the spark was weak on just one cylinder when that cylinder shares a coil with #1? It's probably not your problem. Look into fuel delivery first.

[TommyT]

Well I switched coils and the problem followed that lead.  I'm going to be replacing the plug boots and the plugs tonight and tear into carbs again to check those out.  Anything else I can check while I'm at it?

[Duke McDukiedook]

If it is your coil your #2 would be bad also. Could be the cap, plug wires or the plug itself. Could be that your jets are clogged and need cleaning. Is your fuel tank clean?

[phil71]

are they new plugs?

[TommyT]

Older plugs but look good.  Switched plugs around and problem stays with same lead.  I was thinking it may be bad boot.  So I got all new stuff today.  Gonna swap it over tonight along with new points and condenser.  But i'm just gonna do one thing at a time to see if I can narrow down the problem. 

When I had carb apart last time all jets were clean and spray would come out everywhere it should, needle and seat looked perfect as well.  Fuel tank was cleaned with The Works toilet cleaner and washed thoroughly, them blown out with the shop vac.  Filled with gas and ran.  Filter looks clean but have already swapped that to eliminate that possibility.  Brand new fuel that runs fine in my other bikes, came from same gas can.

[Duke McDukiedook]

With plugs out do a ground check to the body holding #4 sparkplug close to the engine case to see if you are getting a good spark, that is a good indicator of spark voltage. You want to see a nice, blue spark.

[TommyT]

Yeah it's kind of random decent blue spark to a weak white-yellow spark.  Same spark with different plugs into that boot.

I will change stuff out tonight and report back with my findings.  Thanks for the suggestions so far.  I'm not new to motors at all just these honda SOHC's.

[phil71]

one thing I always try to keep in mind with the hondas is to troubleshoot simple to hard. I'm sure it's gonna be fixed in no time, without a lot of effort.

[CoachDoc]

OK so I got my K8 back together and running but it's not running that good at all.  #4 cylinder is really cold on exhaust pipe and not firing.  It has spark but isn't running good.  So i check the plugs and they are a DPR8EA  and it has the NGK 5K Ohm caps on it.  What kind of symptoms would this cause.  Could it be the cause of my weak spark and cold plugs???  If not any ideas what it could be.  any and all help is appreciated.

I know from absorbing the wisdom of Hondaman that resistor plugs combined with resistor caps is a bad idea. And I do believe it could inhibit your spark intensity. Why not try some OEM non-resistor plugs- cheap and easy.

[TommyT]

WEll I got the new caps and plugs installed and it definitely runs better. BUT still not 100%.  Drained the fuel bowls to see the flow and the #4 carb will drain but then dribble out.  So i pulled carbs off again and there was some crap so I cleaned them all out and reinstalled the carbs.  RUNS PERFECT NOW.  Took it for a little ride and it was great.  Can't wait till Tuesday when I'll ride it to work for the first time since rebuild.

[Danno]

try cutting a quarter inch off the spark lead and put the cap back on you could have a burned wire