Picked up a new horse today, 85 250ES

[sinsayers]

I got home late from the long drive but managed to clean the carb, air filter and slap a new battery in her. Now no spark so I'll do some more testing tomorrow. I practically stole this machine so a few bugs are to be expected.

[atc007]

Nice grab! You're Probably looking for a 85 stator,,but What a perfect machine!

[sinsayers]

tested the coil and the meter said ok, tested a backup coil and it said ok so now I need the 250 big red manual. Are those links still on 3ww? I have looked but keep getting dead links. I think the stator is the problem like you said 007.

[sinsayers]

after looking inside the motor everything looks brand new, even the piston top is carbon free.

[oscarmayer]

my sig has links to download manual in pdf for free.

i agree with the cdi assesment..

[sinsayers]

thanks oscarmayer, when I put my old megohmer gauge on the cdi I get a popping sensation on the bottom prongs. I think this is a no no

[tri again]

does your neutral light come on?

I had 2 machines lose their neutral safety switches in the same day,
and subsequently a no spark condition.

Unscrew the plug cap and see if you have spark directly from the wire?

see if you can click on the following words.

service manual

Keep us posted.
I simply cannot imagine life without a few 250 honda trikes,
so a hearty congratulations to you.

[sinsayers]

Thanks Tri Again. I have neutral light, unscrewed cap and nothing still. Im still going over the trike checking things with the meter, any and all ideas welcome but I think the stator is to be blamed.

[tri again]

Thanks Tri Again. I have neutral light, unscrewed cap and nothing still. Im still going over the trike checking things with the meter, any and all ideas welcome but I think the stator is to be blamed.

yeah, the manual should tell you a few different ways to check components.
either resistance or output.

I think the stator output is ac current and rectified somewhere to dc so the coil can use it.

did the
service manual
link work for you?

[sinsayers]

Sure did Tri Again, I am studying it now. Thanks for all the help guys, Im going to test a few more things tomorrow.

[kb0nly]

Take your voltmeter and set it to AC voltage, if you got clip leads thats best otherwise some test jumpers so you can set it up, connect the meter leads to the stator lead and a frame ground and crank it over, should see voltage on the black/red wire. Some digital meters will pulse so fast that they don't give a good reading, i grab my old analog meter so i can watch the needle jump with every revolution of the engine. But either way you should see pulses going out on the black/red wire to the CDI unit.

I have to disagree that its the stator however... Everyone of these that i fought it was the CDI unit. If you see voltage from the Stator then i would check the ground and connections to the coil, also the pulse generator, and then if all that checks out and your seeing voltage from the stator, pulses to the CDI unit, and still no spark, then its either the coil, which you can ohm out or just swap they are so cheap, or the CDI. I bet on the CDI. I have replaced so many of these little black SOB's...

I just put up posts on here dealing with the CDI on my 84 BR. Its running a universal replacement from DRatv.com now, although i did discover the originals problems and reason for failure but now i have it converted to using a $5-20 CDI versus the $199 dealer part!

[sinsayers]

Kbonly thanks for the information man! I am off tomorrow and plan on breaking into her good so that is first on my list. Again that is very good info and I didnt even think about turning her over to get the reading for my meter's, it makes sense now that you said it and that will be first thing checked.

[kb0nly]

Thats the best way to rule out the stator, cause if you check that and nothing from the stator then its done for. The manual shows how to ohm it out and check the coil but that only tells you if its shorted or burnt open. The stator is just a big coil of wire on a metal form, the two ways they fail is burn open somewhere or the enamel on the wire burns through and it shorts out. Sometimes they short out in the windings so that the coil is effectively smaller than it should be, this will show up when you ohm it out but even more so when you measure its output and its low, like a bad transformer.

The nice thing about these is that there is only four components to worry about when it comes to no spark.

Coil
CDI
Pulse Generator
Stator

The stator generates the AC voltage for the CDI, the pulse generator is like points on an older engine and just tells the CDI when to fire the plug, the CDI ramps up the voltage from the stator to feed the coil which then ramps up the voltage again to its final value to fire the plug. Its really so simple but can be a pain sometimes to get it all working right. I have to say though, i sure do enjoy working on single cylinder engines of this nature. A friend of mine just had problems with her vehicle, computer throwing codes, check engine light, ugh. Took me two days to figure out what might be wrong then another week at the shop to actually fix the problem. What a pain!

One more thing, if you have an old school test light probe with a regular bulb in it, not an LED, that works great for testing the output of the pulse generator and stator as well, you can watch it flash!

[sinsayers]

Thanks for the info man, I do have the light tester so that will be my tool of choice. I'll keep you guys posted

[tri again]

Not sure which model but do remember going blind with the wire diagram.

Seems to me that the kill switch ground is also in the loop for the cdi TO run.
Maye that was a 200x but just another thought on grounds and connections in general.

Nice to review the stator output so thanks to kbonly for the rundown.

AC voltage at cranking speed is hard to see without 4 hands and 4 good eyes
and old school tools for sure.

and yes, Please keep us posted.

Wonder if the reverse light works?
thinking if that was stuck (grounded) it may keep it from starting.

dirty key switch contacts?
I have a couple that need wiggling and need to be turned on and backed off a few thousandths.

Just stumbling in the dark here but will come up with some more ideas by tomorrow.