plug pics opinions

79 kz650 b3
air pods 17.5 and 110's if i recall right now
stock exhaust.. 2 on each side.
cyclinders 1-4

Took the bike for a 30 min ride cruising around a couple WOT's
getting some popping from the exhaust mostly the 1,2 side on deacceleration. its much better since i adjusted all air screws to 1 1/4.
got a few pops out through the carbs to the air filters.


What is your opinion on these.. need to do something to cyl 2 obviously.

how much of a turn on each cyclinder?
am i right in thinking that i read somewhere u turn the opposite on cylinders 3&4 compared to 1&2 and achieve the same results.. enrich or lean?

1

2

3

4

You cant get a good plug read from that short a ride. Take it out for a couple of hours at freeway speeds and a bit of round town rides. Then evaluate.

Popping back in the air filters is generally a sign of lean condition. That said, have you been checking all of the basics, like compression, valve clearances, Ignition timing, advancer, float levels, carb sync and cleaning, possible fuel starvation? All of the basics must be done before considering jetting adjustments. But 3 of 4 of your pics look lean.

well this was my first ride over 35mph and off the residental housing plan roads.

me going for an hour long ride on a highway will take some time

these plugs were all mostly black before.. so i guess the bike was ridden long and hot enough to clean up the plugs?

i have yet to fine sync the carbs.. this is all a learning process for me. have about 40 miles under my belt.

i have had the carbs all apart / points switched to dyna s ignition / timed /compression

do i turn the air screws in or out to enrich.. and is it the opposite on cyl 3&4 compared to 1&2?

thanks

Doesn't sound enough for a plug reading, remember that as you want to make adjustments you need to make the carb's stay in the range you want too look at. So if you want to look a the needles then you should avoid Idle and WOT. Etc.

basically im trying to get this bike safe and reliable per se while i learn how to ride.

1,3,4 look lean.

basically im trying to get this bike safe and reliable per se while i learn how to ride.

Safe. Reliable.

I think the best advice, is to get the manual.

There is some 20+ pages of maintenence material to go through and perform, before you start dinking with the carbs. This is of course, up to you.

To answer your question, the screws all perform the same operation. If they are closest to the engine half of the carb, they are a mixture screw, and out is richer/in leaner. If closest to air box/pod side of carb, they are an air screw, out is leaner/in richer.

If your carbs are nice and clean/proper fuel levels/mix screws same, then there is something going on in the #2 cylinder.

What were your compression #s?
Have the valve gaps been checked?
Fuel levels checked?
Strong spark on all 4 cyl?

GL.

HT8R wrote:

You cant get a good plug read from that short a ride. Take it out for a couple of hours at freeway speeds and a bit of round town rides. Then evaluate.

I agree, especially if the plugs were not new to start out. We didn't see a "before" so it's hard to judge the "after" without new plugs.