need spark plug read help, pics
- Thread starter reelinfeele
- Start date
Are those two plugs from two cylinders or the same plug? If they represent both cylinders, I'd say you're looking pretty good given how similar they are. Tough to get both cylinders tuned exactly the same.
But you could richen it up a tad. What RPM and road speed did you chop at to get this color? You may just need to turn in the air screw if this is low RPM or increase the main jet size if it's at full throttle.
But you could richen it up a tad. What RPM and road speed did you chop at to get this color? You may just need to turn in the air screw if this is low RPM or increase the main jet size if it's at full throttle.
crazypj
Split personality, I fake being smart
That's pretty good
Did you wipe insulator or is that exactly as it came out of engine?
I would try one heat range lower then one hotter, (from B7 to B8 then B6 or similar)
The ground strap is running a little warm but otherwise it's real close to correct mixture.
Richening it up on main jet will lose power as it will be too rich everywhere.
Everyone is only looking at insulator but threaded part shows its running a little rich (which is why it's black)
Modern fuels don't give a 'nice tan/chocolate brown' colour reading
BTW, what bike is it?
Did you wipe insulator or is that exactly as it came out of engine?
I would try one heat range lower then one hotter, (from B7 to B8 then B6 or similar)
The ground strap is running a little warm but otherwise it's real close to correct mixture.
Richening it up on main jet will lose power as it will be too rich everywhere.
Everyone is only looking at insulator but threaded part shows its running a little rich (which is why it's black)
Modern fuels don't give a 'nice tan/chocolate brown' colour reading
BTW, what bike is it?
Too rich, or not enough advance.
Well that's what it would indicate if that were a clean plug chop at full open, top revs. If that was just putting around it doesn't tell us anything. The tips are not hot enough to burn clean so it's either retarded or more likely not at full load.
If you are trying to get the main jets right, it must be flat out under load to get the plugs up to peak temperature. If that's mixed conditions then the plugs are not hot enough to read and we have no idea what part of the range you were running.
BTW, what fuel was that? It almost looks like lead coloration. Was it leaded fuel or E10 street gas?
Well that's what it would indicate if that were a clean plug chop at full open, top revs. If that was just putting around it doesn't tell us anything. The tips are not hot enough to burn clean so it's either retarded or more likely not at full load.
If you are trying to get the main jets right, it must be flat out under load to get the plugs up to peak temperature. If that's mixed conditions then the plugs are not hot enough to read and we have no idea what part of the range you were running.
BTW, what fuel was that? It almost looks like lead coloration. Was it leaded fuel or E10 street gas?
reelinfeele
Been Around the Block
its a kz400. I run premium unleaded. plugs are b9's. it is hunting for idle, up and down. I am running pods on a stock exhaust. These are straight out of the engine, choped it at 5000. I have a larger set of primary mains coming. it has 70's now (stock) am going up to 80's. Thanks for the input, I am not sure how the ethanol is affecting the fuel these days. the book calls for b8's, I get the same same color from 7, 8 , 9 plugs. I know tan is the target color but these dont look too bad. bike has CV32 keihin's, floats are perfect, after 300,125,478 tries. synch is pretty much dead on.
