'90 Warrior - need help testing electronics

[boston350]

HI folks, first post here. great site, been learning lots.
I picked up a non-running '90 Warrior the other day and testing out all the electronics per the manual. It has a very weak spark currently.
My first question is about using my digital multimeter to measure the resistance on parts. the manual calls for R x 1, R x 100 etc - my digital multimeter has settings like 200, 2000, 20K, 200K etc. I thought the R x 1 was the same as the 2000 ohm setting and did my first test at that but results were way off. I ended up bumping the meter down a range and got closer - but not sure if that is correct.
some examples:
ignition coil - primary, spec .36-.48. tested on the 2000ohm settings I got 000. I moved it to 200 Ohm and got .7 - closer to expected but out of spec.
I was able to do this for most all the parts to get something close to expected, just not always in range - except for the stator pickup coil that I had to go down 2 ranges.
on the ignition secondary coil, Rx1000, spec 5.44 - 7.36 I came up with 10.5. But comparison I pulled out an old analog meter than had a setting for R x 1000 and tested it, this time I got 5.9.
So now I am more confused.
Anyone able to point me in the right direction?
thank you much!

 

[DeadLastRacing]

Welcome! A weak spark is the sign of a failing stator. That's about all I'm good for. Best of luck figuring it out.

 

[yamarider]

Meters vary from manufacturer to manufacturer so the manual can't tell you what setting your particular model needs to be in to get the correct reading. Rx1 on a meter such as you described will be your lowest setting, 200. What that means is the maximum resistance your meter can read at that setting is 200 ohms. So .7 would be the right reading in the test you used as an example, assuming you're probing the right wires and your tester is calibrated properly. If you have a real el-cheapo tester it might not be accurate enough in the low ranges for these purposes (harbor freight?)

For your stator pickup coil, what range did you have your digital meter in when you got 10.5? It sounds like you got a good reading with your analog meter, so the digital was probably in the wrong setting, or again, if it's a cheap one it might not be calibrated properly.

If any of this doesn't make sense let me know and i'll try to explain it better. I'm an electronics technician so you're talking to the right guy.

 

[1998yamahawarrior]

i would also check the little ground wire in the picture. it has a quick connect on it and it can corrode and break. i had that cause a weak spark this summer. i found it after replaceing the pickup coil and the ignition coil because they tested out of spec. now of coarse she starts without an issue.

 

[boston350]

Ok thanks - sounds like I came to the right place - thanks.
the digital multimeter is $30 Craftsman, only a year or so old so it should be pretty accurate. the Analog is probably 20 years old.

so 200ohms is the lowest setting, and the max it will read? so the 2000K ohms is the highest, and less ohms?

pretty sure I probed the right things, folllowed the pics in the manual and triple-checked everything. the garage was about 45 degrees - if that changes the result some over the 70 degree test spec.

the 10.5 digital and 5.9 analog were the readings I got on the Ignition Secondary coil. Tested first at the 2000K ohm setting - got the 10.5 set to 200K ohms.

other test results:
spark plug cap - 4.5, spec is 10K
ignition primary coil - .7, spec is .36 - .48
ignition secondary - 10.5, spec is 5.44 - 7.36
stator charge coil - .90, spec is .70 - .86
stator pickup coil 208 - in spec for yellow/blue and 275 - in spec for white/green&red.

since I couldn't get a close reading from the spark plug cap - and you test the ignition secondary coil from terminal to cap, could that be effecting the results?

I have a new stator on order, trying to determine if these results mean my CDI is shot as well - or if I'm have trouble testing it. Or maybe it's just the ignition coil, but I don't know if those would fail partially and still make some spark.

thanks again!

 

[boston350]

1988 - thanks for the hint on the ground - I will double check that as well. already had to rewire the main fuse holder to get it to wake up again.

 

[yamarider]

so 200ohms is the lowest setting, and the max it will read? so the 2000K ohms is the highest, and less ohms?

Close, 200 ohms is the lowest setting, which is the lowest resistance it will read. The .5-ish that the ignition coil specs at is a very low resistance, almost a short. 2000 k ohms (which is really 2 meg ohms) is a very high resistance, very little current will flow through high resistances)

If you haven't figured it out yet, the "K" represents 1,000. Example, 2.2K ohms is 2,200 ohms. Not really that important, just a little electrical lesson for ya.

the 10.5 digital and 5.9 analog were the readings I got on the Ignition Secondary coil. Tested first at the 2000K ohm setting - got the 10.5 set to 200K ohms.

My computer is being contrary so I can't pull up the service manual to compare to what you've posted. What is it saying about testing the ignition secondary? And what kind of manual are you using, Clymer or a factory Yamaha manual? Clymer manuals are known to have bad specs.

 

[boston350]

Ok - thanks, I think I got the the measurements now. yep, got the K = 1000.
using the clymer manual, specs for a 1990 warrior.
book says specs for the ignition secondary are 5.44 - 7.36, similar to other year specs.
test method - end of spark plug cap to main terminal.

Thanks

 

[boston350]

checked the ground today, looks good.
unbolted the ignition coil and brought it inside to warm up for an hour and retested. This time the Secondary coil was slightly higher, 11.2 vs 10.5 from the garage. Big change was that I was unable to get any reading off the primary coil with it just sitting on the table, it shouldn't need to be grounded to the frame for a reading should it?
thanks

 

[boston350]

swung by the local bike shop - not dealer and picked up the new stator. I also brought in the ignition coil and had him test it out also. Got the same results I had, so ordered a new one. will put it all in next week and see if we have success.

thanks for the help guys

 

[1998yamahawarrior]

good luck!!

 

[boston350]

Well I'm stumped now, or at least at a roadblock.
picked up a new ignition coil and tried it, still weak spark.
put in the new stator, no spark, switched the two wires - back to weak spark.
tried with the old ignition, still weak spark.
does that just leave the CDI box?

 

[boston350]

went through all the connections on the thing again. unplugged and cleaned all the bullet connections and the grounds - found a few that had dirt in them still. spark is a bit brighter now. also found one black wire coming out of the set that goes to the ignition coil that wasn't attached, so hooked that back up.
will try it again tomorrow and see what happens.

 

[boston350]

I checked the manual, the black wire that was unplugged, it was paired with the black/yellow wire - clutch switch. oddly enough, they don't go anywhere. I don't see anywhere around the clutch that they would attach.
hooked everything up at tried to start it up again, with the plug in the motor it will turn over maybe once. the solenoid clicks away like crazy but doesn't seem to have enough to roll the motor over.
may not be related, but the neutral ligtht isn't coming on today.
thanks for any help

 

[yamarider]

Does it have the stock clutch perch on it? It would have a sensor on it just like the parking brake sensor. When the clutch perch is removed the switch is bypassed by connecting the 2 wires running to the sensor together, looping it out.

Is the solenoid clicking or is it buzzing? Big difference in troubleshooting.

 

[boston350]

don't see any perch - didn't see a parking break, as described in the book or manual either though. it's a clicking noise like really fast Morse code. spins fine and no funny noises when the plug isn't in(not fighting the compression of the engine)

 

[yamarider]

Don't see any perch... what do you mean by that? The clutch perch is the thing the lever pivots on! If it's the stock one it will have a gadget to set the parking brake as well as 2 sensors with wires coming off them for the clutch and parking brake safety circuits.

If it has a problem turning over with the compression it means either your battery is weak, the starter is shot, or you have loose or damaged cables going from the battery to ground, battery to solenoid, or solenoid to starter.

 

[boston350]

I checked the resistance on the solenoid,showed to be 5.9 vs 3.5 as spec'd by the manual. It says more than 10% off that to replace.
Is the rapid click and not able to turn the motor over(with plug in) a sign of the solenoid being bad? would it be a contributor to the weak spark?
thanks again for the help!

 

[yamarider]

I've never had a solenoid only partially work like that. In my experience either they work or they don't, not halfway. It's a pretty simple device, testing slightly out of spec wouldn't concern me, and it couldn't affect the weak spark in any way. A rapid clicking (sounds more like a buzzing sound) is almost always an indication of insufficient power to turn the motor over.

What happens with it now if you jump across the solenoid with a screwdriver with the spark plug in?

 

[boston350]

ok, good to know. I'll charge the battery again and try to jump it.
so it sounds like the weak spark is still pointing to the CDI?

thanks