gs450 running one only one side

[dickidav]

1983 gs450 runs on one side not other. there is spark, gas, no air leaks. the right side pipe gets hot the left doesn't. it will run with one plug out but switch them and nothing.
the side that runs the plug is fluffy black. the other side wet. i trimmed 1/2 inch of plug wire off and put the boots back on nothing changed.

[almarconi]

Are you running the resistor type plug boots? If you are, what resistance are you getting?

You have spark on both plugs? Do you have compression in both cylinders?

When was the last time you adjusted the valves?

[snark]

Check the wiring to that side coil for cracks...that was my problem.

[dickidav]

i have spark in both plugs, compression in both cyl. don't know about the type of boots. doing valves this next week. raining every day til then.
checked wiring, cut 1/2 inch off and replaced the boots.

[chef1366]

Ignition related if not carb. Even though you have spark you have a built in curve in the igniter and this can fail.

[dickidav]

should i buy new coils? don't know/understand much about electrical. thanks
or igniter?

[chef1366]

If it is sparking it's not the coils. I was stating it could be the igniter.

[dickidav]

is there any way to test it?

[almarconi]

is there any way to test it?

There should be a procedure in the service manual.

[dickidav]

got the book in front of me. yes there is. would this (if it is the problem) take care of the non firing cyl.?

[almarconi]

The igniter receives a signal from the signal generator which then tells the coil to fire. So if your igniter is bad then no fire.

[dickidav]

there is spark in both plugs. if bad would there still be spark? just not strong enough to fire the cold cyl, right?

[almarconi]

Even if you have spark in the air, it doesn't mean that you will get spark when under compression. Your igniter is probably OK. I would first adjust the valves..you said you have compression is it the same in both cylinders?

The spark could be weak..what voltage are you getting at the coils?

Check the coils. Measure the primary and secondary resistance..the book explains how.

[chef1366]

The igniter receives a signal from the signal generator which then tells the coil to fire. So if your igniter is bad then no fire.

Not always true. I've seen bad igniters in running bikes. Bike ran badly but did run.

[dickidav]

thanks for the help. i will be able to get into it at the start of the week. after the valve adj.