gs550 running on 2 cyl. coil grounding??

[jpmanguy]

i got a gs550 that runs on two cylinders. i have done a few tests and i think that my coil is being grounded out on the inside.

1. i get power to both of the coils with them unplugged and as soon as i plug in the left coil (#1 + #4) the voltage drops and i can get a very small reading (like .1V) and i will do the same thing with the other coil and the voltage only drops a few volts like it should.

2. i have checked ohms between the wires going to the coils and the wires coming from the coils and they are the same on both sides.

3. checked the coil ohms (between the spark plug wires on each coil) and on the left coil i read 53.4 on the 200k ohm position and on the right coil i read 34.0 on the 200k ohm position.

i have replaced the signal generator because i thought it was the problem before but i tested it with the old one comparing ohm readings and they are the same so im suspecting the old one is good (there goes $150!! )

i was supposed to be selling this bike but this problem came up and now im trying to figure it out and i really dont want to be buying anything else for it unless i know for certain it is the problem.

any ideas on what to do?? please help!!

 

[chuckycheese]

Coil

Coil

Your secondary ohm reading (plug cap to plug cap) should be approximately 31-33 ohms so you may really have a bad coil. I'd suggest you swap the coils around to see if the problem goes with it to #2 and #3. While you're at it, also check out your plug caps. It's a bummer to replace parts that don't have anything wrong with them. I often wonder how many spare solenoids there are out there? (People love to replace them.)

 

[jpmanguy]

well i think one problem is that i have bad plug caps because the left coil with the caps on is at 53k ohms and without them they are at 14k or something close and the right coil is 30 something k ohms and without the caps its at 14k ohms. i checked the wires going from where the coil wires plug into and where it plugs into the ignitor and they are all fine at about 3 ohms each. nothing dramatic.

but what i dont understand is that i brought the coil that is supposedly bad (the left one) into a suzuki dealer and the tech. tested it on one of those arc jumping machines and it jumped a big gap and he said it was good. i dont get it!!!

 

[jpmanguy]

did another test. anyone got an answer to this?

put the multimeter leads into the plugins for the coils. first did the right side (good side, side i get spark on) i turn the key on and i read 10V. i crank it over 180 degrees and the voltage drops out and i dont read anything then i crank it 180 degrees again and the 10 volts is back. now on the other side (left, bad side with no spark) i do the same test. reads 10V and i crank it 180 degrees and it still reads 10V and i do it again, still 10V. so for that side im consistantly getting 10 volts and the other side it is 10V every 360 degrees. guessing this is something i should be concerned about. where would this come from? ignitor?

 

[chuckycheese]

Coil

Coil

well i think one problem is that i have bad plug caps because the left coil with the caps on is at 53k ohms and without them they are at 14k or something close and the right coil is 30 something k ohms and without the caps its at 14k ohms. i checked the wires going from where the coil wires plug into and where it plugs into the ignitor and they are all fine at about 3 ohms each. nothing dramatic.

but what i dont understand is that i brought the coil that is supposedly bad (the left one) into a suzuki dealer and the tech. tested it on one of those arc jumping machines and it jumped a big gap and he said it was good. i dont get it!!!

It certainly does sound like you have a bad spark plug resistor cap.....and they're important! I happen to have a brand new, stock coil and I just took an Ohm reading at the wire ends (no plugs). It measured 12.85K Ohms. If you're getting a 14K reading, that should be fine.

I'm not confident that it will solve your problem but it's important, nevertheless.

 

[Suzuki_Don]

Your secondary ohm reading (plug cap to plug cap) should be approximately 31-33 ohms so you may really have a bad coil. I'd suggest you swap the coils around to see if the problem goes with it to #2 and #3. While you're at it, also check out your plug caps. It's a bummer to replace parts that don't have anything wrong with them. I often wonder how many spare solenoids there are out there? (People love to replace them.)

CHUCKY I think this post should read 31-33 K ohms. Just don't want anyone to read this post at a later date and be looking for a reading like this.

 

[chuckycheese]

Right, you are!

Right, you are!

CHUCKY I think this post should read 31-33 K ohms. Just don't want anyone to read this post at a later date and be looking for a reading like this.

Of course, Don, you are exactly right. Good catch!

 

[jpmanguy]

well i did the test with using the other coil and trying to get it to spark on the other side and it didn't spark so im guessing its the ignitor? i replaced the signal generator so thats brand new.