Spark plug reading different

[Waternut]

Ok so my spark plugs always read a little different from each other in the past and I contributed it to bad spark plug wires. Now I have a total loss system and the spark plug differences are actually more dramatic. The front cylinder looks almost too rich and the back cylinder looks almost too lean. What gives?

BTW, I have a single carb.

 

[WaveDemon]

you need to pressure test your motor.

 

[Waternut]

165psi on both cylinders with a stock milled head...

Just in case you meant leak check, I did that this winter and after fixing multiple leaks it held 10psi for 10 minutes.

 

[D-Roc]

well then i guess your not leaking water in one cylinder.

 

[Waternut]

well then i guess your not leaking water in one cylinder.

That's a plus :Banane35:

 

[D-Roc]

ported cylinder?

 

[sflsurfrider]

id do another leakdown test. if you had 'multiple leaks' last winter, its possible to have one more by now.

 

[Waternut]

ported cylinder?

It doesn't look ported but I can't really measure it very well to be completely sure. I know the port wasn't raised for sure.

id do another leakdown test. if you had 'multiple leaks' last winter, its possible to have one more by now.

Although another test wouldn't hurt too much, it was even doing this on my first ride out.

 

[sflsurfrider]

how did you do your leakdown test? did you remove just the carb and pipe? or both manifolds?

 

[Waternut]

how did you do your leakdown test? did you remove just the carb and pipe? or both manifolds?

I only removed the carb and pipe and plugged the two inlets with a pvc test plug. Left the manifolds in place.

 

[sflsurfrider]

hmmm... reeds maybe?

have you tried switching the plug wires to see if the plug conditions switch?

heres a thought.... maybe your pulse hose or pump diaphragm is shot. is the lean plug on the same cylinder as where the pulse fitting is?

:dunno:

 

[Waternut]

Well over the winter, the reeds looked fine. I have not switched plug wires yet since my original ones could only go one way. I'll give that a shot next time out and see what the results are.

Pump diaphragm could be shot but I know it's not leaking. The rich plug is actually next to the pulse fitting.

Yeah exactly...:dunno:
I've been riding it a while like this because I couldnt' really see anything that could be causing it other than a funky flow pattern from the carb. I may just keep going "as is" until it sh*ts the bed.

 

[sflsurfrider]

are you saying that youre still running the same coil that youve been using the whole time youve been having this problem?

 

[Waternut]

No the entire electrical system including plugs and wires has been replaced.

 

[ski4]

maybe a stupid thought but have you put in some new plugs?
maybe for some reason one is burnign hotter than the other?

perhaps that would make no sense but it just came to mind