87 Suzuki DT150 SS - partial spark? per coil?

[hankll]

This motor has 2 spark plugs per cyl. - Originally I thought I had no spark on right bank, based on visual condition (clean, gas wet) of new plugs. Today I opened black Ignition coil box and blew air all around connections, and checked connectors for tight fit, then I ran spark test on all cyl - result was good fire on 2,4,6 both plugs each cyl, and on 1,3,5, good fire only on outer spark plugs but no spark on inner spark plugs. On this motor, one ignition coil for each cyl with 2 spark wires to each cyl. Am I missing something here? Is it bad coils 1,3,5, or is it a ground problem on the ignition coils on that side and somehow only affecting the inside set of plugs? Does the spark going to each set of plugs per cyl fire at the same time? It seemed to start way better than it did at the lake Saturday, but still seems as if its missing. And it doesn't seem to idle down with the adjustment knob on side of motor. but could be that it didn't warm up yet, I guess.

 

[johndezman]

Re: 87 Suzuki DT150 SS - partial spark? per coil?

while i don't have experience with the dual plug model, i will share what i do know.

the suzuki ignition has a low oil reset that once tripped needs to be manually reengaged by pressing the button on the electronics box on the starboard side of the engine. it is supposed to kill the ignition to one bank of cylinders. this device is intended to let you know when engine is low on oil and prevent damage to the motor. a simple push should be all that's necessary (i assume motor off when pushing)

i cannot speak to whether it kills one of the two circuits on a twin plug engine.

are there multiple grounds evident on each coil - i don't recall a ground wire but its been a while since being inside the ignition box on my 200.

if i remember correctly, there are only three triggers on the flywheel which should indicate that if one is firing they should both be firing.

i'd first try the button and if that doesn't work i'd move a known good coil to the bad position and retest to see if the fault follows the coil.

browns point is a great source for parts if you do need them.

 

[hankll]

Re: 87 Suzuki DT150 SS - partial spark? per coil?

Thanks JohnDezman ... Sometimes I need to be clubbed on the head to be shown a way to test for something! I had changed spark plugs around and was not getting any results. Actually bought new plugs and same result.

But today after installing new set of plugs I was messing around inside CDI box again and pushed and pulled on connectors all around, lo an behold I had fire! But only problem was I also moved spark plug cables around so they weren't resting against heads in case they were leaking spark. So one or the other has got my fire back. I'm going to investigate which and retest to see if I lose the spark again. I'll try to narrow it down so I have good spark that don't go away when it feels like it.

But that doesn't mean that the problem isn't in one of the coils connections, so I'll try what you suggested if I can't get spark to go away through the spark cables or wiring harness going to the coils.

I had already done the oil reset before and no spark, so I don't think that was it.