What do you set the dial to on a digital multimeter in order to test the ohms/resistance of the ignition coil? I've tried every setting (2M, 200k, 20k, 2k and 200). The shop manual for my DT3 says it should read 0.9 for the primary coil. What I get as a reading jumps all over the place with varying figures and never lands on just one figure. I've tried touching the red and black probes together first to zero out the multimeter, but the same results occur.

Four words "Some Digital Meters Suck" 

You need it on the lowest scale which sounds like 200. 

I don't have a high-end digital meter and they all do the same thing you're describing.  Jump all over when trying to read low resistance.

I only use the same type of meter that Yamaha did back then...  an Analog (swinging needle) meter with an "Rx1" scale.  (The Rx1 scale is important)  I've had my (high end) Simpson meter for decades...  but you can find new analog ohmmeters with the Rx1 scale for around $20 or so on ebay and even Amazon the last time I looked.

Okay, thanks MarkT! What I have, I got from Home Depot, a Commercial Electric brand. Once I get an analog one, what do I set that one to?

These all seem to have an Rx1 scale...  just the first three with Rx1 scales that popped up on Amazon.  I don't own any of them.  (Some of the other analog meter choices that came up have Rx10 scales as the lowest setting which probably won't work for you and I would not buy.)

www.amazon.com/Gardner-Bender-GMT-318-Mu...nction/dp/B00291X79O

www.amazon.com/Multimetro-Multimeter-Uni...rician/dp/B0C89RCNT1

www.amazon.com/White-Deer-Multimeter-Mul...itance/dp/B08NN25XSW

I have that same Commercial Electric meter and I think a low end Gardner-bender digital meter from Lowe's...  plus of course the Harbor Freight digital meter they used to give away free with coupon.  They all work pretty good for most auto and home needs where you don't need to measure low resistance.

Lowe's by me has an analog meter for like $15 but it only goes down to "Rx10" so not good enough.  All the Lowe's analog meters that have an "Rx1" scale have to be ordered. 

And I didn't answer your question...  0.9 ohms would be measured on the "Rx1" scale. 

With analog meters make sure you always touch the probes together and use the adjustment knob to get the needle set to "0" (swing all the way to the right).  You need to do this every time you switch scales too. 

I'm not sure about digital meters, but analog meters tend to "release the magic smoke" if you attempt to test voltage with the knob set to resistance (ohms).  I've destroyed a few meters that way  

The only reason I still have my Simpson is it has a fuse that blows when you attempt to measure volts with it set to ohms...  I think I've replaced the fuse 3 times. 

Super! Thanks again.

Ok. I ordered the first one on your recommendations list. There is no adjustment knob to zero out, as you had suggested. I touched the probes together, anyway and the needle goes over to 3 not zero. I tried to attach a photo of the reading I get, but it didn't work. (If someone has a way around so I can post, that'd be great.) The needle sits on 4.3 of the V-mA scale. I have no idea what I'm doing. Thanks for your help.

I've never seen an analog ohmmeter without a "zero adjust". It looks like there's a thumb wheel on the left side.

You are so right. I didn't even see that. Duh! Okay, I adjusted it until it read zero, then checked the ignition coil. The needle went to 8 on the V-mA scale. Still not the 0.09 the manual says I should get. Is this bad?