View Full Version : Was having 250r electrical gremlins
Billy Golightly
06-11-2019, 09:01 PM
5 coils. All tested out of spec as per manual
Hard to see in pics but was 1.7 and spec was .16 to .2 that was one of them.
Wound up putting one back on and it sparked some at least, not great but enough to run...calling it good for trikefest. https://uploads.tapatalk-cdn.com/20190612/79417e552d43e5c26ebf19e7311c1a65.jpghttps://uploads.tapatalk-cdn.com/20190612/2108426c456a6042a124a0e0b884ee33.jpghttps://uploads.tapatalk-cdn.com/20190612/20444dfb7eae9259887a915df799969e.jpg
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roonie
06-11-2019, 09:48 PM
funny...the epoxy on each one of them is a different color. Its like they all have their own personal identity
El Camexican
06-11-2019, 10:16 PM
Might want to try a Rotax coil ;)
ps2fixer
06-11-2019, 10:29 PM
Maybe it's not the coil? There's a capacitor in the CDI box that get's charged up from the exciter coil, then when the pulse generator say to fire, it dumps that charge to the coil. Maybe that capacitor is weak, any chance you have another CDI to test my theory?
I assume the exciter coil tests in spec. Doubt you'd have the tool, but if you happened to have a peak voltage tester (adapter that plugs into the multi meter), you could check if your exciter coil is putting out 100v+ at kick start rpm. If that tests good, do the same test on the black/yellow coil wire to ground and see if the CDI output is similar.
Also, multi meters are not always super accurate 1 ohm and lower testing. Do you get a 0 ohm reading when you short the probes together? The meter I use all the time (RadioShack brand) reads 0.0 when I do that, the cheap chinese one I bought off ebay looks exactly like yours but mine is black and no outer shell, and it reads 1.4-3.6 ohms. It's really inconsistent and changes with how well you hold the probes together.
For fun I grabbed my 85 350x coil off which I'm pretty sure is the same specs as yours, and check out the meter readings. 0.1 vs 6.2. I trust the radio shack one a lot more than the china knockoff, I also have a Fluke floating around, but it might be at my dad's house. Btw, the coil works great on my machine, so I'd assume it's in spec.
Billy Golightly
06-12-2019, 06:24 AM
Maybe it's not the coil? There's a capacitor in the CDI box that get's charged up from the exciter coil, then when the pulse generator say to fire, it dumps that charge to the coil. Maybe that capacitor is weak, any chance you have another CDI to test my theory?
I assume the exciter coil tests in spec. Doubt you'd have the tool, but if you happened to have a peak voltage tester (adapter that plugs into the multi meter), you could check if your exciter coil is putting out 100v+ at kick start rpm. If that tests good, do the same test on the black/yellow coil wire to ground and see if the CDI output is similar.
Also, multi meters are not always super accurate 1 ohm and lower testing. Do you get a 0 ohm reading when you short the probes together? The meter I use all the time (RadioShack brand) reads 0.0 when I do that, the cheap chinese one I bought off ebay looks exactly like yours but mine is black and no outer shell, and it reads 1.4-3.6 ohms. It's really inconsistent and changes with how well you hold the probes together.
For fun I grabbed my 85 350x coil off which I'm pretty sure is the same specs as yours, and check out the meter readings. 0.1 vs 6.2. I trust the radio shack one a lot more than the china knockoff, I also have a Fluke floating around, but it might be at my dad's house. Btw, the coil works great on my machine, so I'd assume it's in spec.
That's pretty interesting. I've always had hit or miss luck with taking the resistance on these parts and I guess i never considered maybe my meter was a POS...ha. This one came from Lowes because I didn't want to pay for a fluke
Jd110
06-12-2019, 10:52 AM
Good info, already. I’ve always checked resistance on the leads before a test. If im measuring one ohm between leads, I’ll deduct that from the test.
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ps2fixer
06-12-2019, 03:06 PM
FYI, the cheap meter I showed in the pic was like $3 each on ebay lol. Over like 50 ohms it's fairly accurate, but it's horrible under that, worse near 0 ohms. Lead wires should be less than 1 ohm though unless you have like 10ft long leads or more, kind of depends on wire size too.
Testing the leads and minusing that works if it's an accurate meter. Not sure if you guys are aware, but most multi-meters inside have a calibration adjustment, I'm like 80% sure the Chinese ones are not calibrated. If your meter has the POT to adjust it, you could calibrate all your meters to read the same, at least in a target range, like 1/2 range (100ohms for 200 range, 1000 ohms for 2000 range, etc), you just need a meter to base the measurements on. You could get a few low tollerance resisters at different ohms and calibrate to them. Should be pretty easy to get 1% ones, standard is 5 or 10%, can't remember off hand.
I'll be honest, I'm not a big fan on the Fluke meter, that's why I don't know where it's at current lol. The Radio shack one I've used since I was a teen and the store wasn't closed lol, I think it was like $20. I don't like the Fluke auto averaging system, I like more instant feedback. The radioshack one does it a little, but it's because it has the auto range stuff. For the short test (beep), it's near instant though, the Fluke is like 1/2 a sec or longer.
Anyway, back on topic, I'd just say grab all the coils with you, just encase. Easier to swap and test for good spark at trike fest, instead of trying to find someone with a spare coil to buy/use.
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