is this an ignitor problem? (or maybe coils?)

[steve_crabb]

i have a 1981 gs550 and pipes 3 and 4 were running cold. i switched the wires on the back of the coils and the problem switched to pipes 1 and 2. i also checked the voltage directly off the battery and it had 11.45 volts and then i tested the wires that were hooked up to the back of the coils and one coil was getting no juice at all and the the other one was getting 7.95 volts. at first i thought it was a coil problem then people sugested that it might be an ignitor problem instead. i have no clue if this is an ignitor problem or a coil problem? i would love any advice.
i'm not sure of this matters or not but the one of the coils was hooked up to pipe 1 and 3 and the other one was hooked up to 2 and 4. i'm not sure if this matters just thought i would let you know. any advice would be a huge help because i know very little about motorcycles. thanks~!!!

[Billy Ricks]

The coils are hooked up wrong to start with. One coil should go to 1&4 and the other to 2&3. You should be able to tell which goes where by the length of the plug wires. When you checked voltage did you place the + probe on the orange white wire and the other to an earth ground or did you use the ground wire to the coil? If you used the wire to the coil you may not get a reading based on where the crank is positioned. UYse an earth ground on bare metal somewhere on the bike. Clean and tighten the connections at the ignitor and make sure you have a good ground to the engine. If you want to bench test the coils to get an idea of their condition the primary side where the ignitor hooks up to the coils should give a resistance readin of 3-5 ohms. It won't matter which probe goes on which terminal. Take this reading with the wires from the ignitor removed form the coils. Then to check the secondary readings place one probe in plug cap number 1 and the other in plug cap 4. You should get a reading of 30,000 to 50,000 ohms if you have stock coils. Then do the same with caps 2 & 3 and check your readings.

[steve_crabb]

good advice

Thank you for you input on how to check the coils. ya i did put the possitive on the orange and white wire and i placed the negative on the negative of the coil so maybe that is why i got no reading? so if i still get no juice to the coil does that mean that the ignitor is bad? how do i know if the ignitor is bad? and i figured the coils were wrong but since one coil was hooked to 1 and 3 and the other to 2 and 4 i'm it still doesn't explain why pipes 3 and 4 were cold and why the problem switched to 1 and 2 when the wires got switched. any additional thoughts??

[Billy Ricks]

Thank you for you input on how to check the coils. ya i did put the possitive on the orange and white wire and i placed the negative on the negative of the coil so maybe that is why i got no reading? so if i still get no juice to the coil does that mean that the ignitor is bad? how do i know if the ignitor is bad? and i figured the coils were wrong but since one coil was hooked to 1 and 3 and the other to 2 and 4 i'm it still doesn't explain why pipes 3 and 4 were cold and why the problem switched to 1 and 2 when the wires got switched. any additional thoughts??

The condition switched because the primary wire positions were switched. One set of cylinders fired properly with the primary wires on one coil then when you switched the primary wires the other two started firing. With the position of the plug wires, which are wrong, you have one pair of cylinders firing on the wrong stroke. Straighten that out before you worry about the ignitor. The ignitor isn't the problem based on what you've described.

[Billy Ricks]

In case I'm not making myself clear it's the spark plug wires themselves that are hooked up wrong. One coil fires 1&4 and the other fires 2&3. You should have an orange/white wire to each coil from the ignitor. The white wire from the ignitor is for the coil for 1&4 and the black/yellow wire is for the coil for 2&3. That's assuming you primary wires are the same as mine.

[steve_crabb]

ok i'll be home tomorrow night and straighten out the spark plug wires and make sure the right wires are going to the coils. do you think this might be the only problem with pipes 3 and 4 running cold?

[Billy Ricks]

ok i'll be home tomorrow night and straighten out the spark plug wires and make sure the right wires are going to the coils. do you think this might be the only problem with pipes 3 and 4 running cold?

If you have the plug wires crossed up I'd say it's probably about 99% certain to be your problem.

[steve_crabb]

thanks

great! i really appreciate your help! i'll be home tonight and i'll give that a shot and let you know how it turns out! thanks again.
steve

[steve_crabb]

it worked but now it wont work

Thank you so much for your advice! i switched the plug wires and all pipes are now running hot! so that is awesome! i got it going after a lot of cranking and it ran fine! the rpms did jump to 4k but when i took it for a ride it settled down. it was idleing great and then i turned it off and tride to start it again and it wouldn't start i tried and tried and still now luck. i pulled a plug and it looked like it was dry. i just put in a new petcock so i know that isn't the problem but i'm guessing i need to pull the carbs and do something about that. but what do you think needs to be concentrated on when i pull them, or do you think that this is the problem? thanks again for you help!

[Billy Ricks]

Thank you so much for your advice! i switched the plug wires and all pipes are now running hot! so that is awesome! i got it going after a lot of cranking and it ran fine! the rpms did jump to 4k but when i took it for a ride it settled down. it was idleing great and then i turned it off and tride to start it again and it wouldn't start i tried and tried and still now luck. i pulled a plug and it looked like it was dry. i just put in a new petcock so i know that isn't the problem but i'm guessing i need to pull the carbs and do something about that. but what do you think needs to be concentrated on when i pull them, or do you think that this is the problem? thanks again for you help!

If it sat fr any length of time you need to do a carb cleaning and replace the o-rings on the mainfolds if you bike has bolt on type rubber manifolds. There is a carb cleanup how to on the site's homepage that will guide you through the process. New o-rings throughout the carbs would be a good idea as well. Robert Barr who posts here can help you with an o-ring set at a great price. I think his handle is robertbarr.