85 250SX, No Spark?

[zainyD]

Tried reading up on this topic before I posted, but I'm still kind of confused.

Here's the deal, I have an 85 250SX that I've tuned up, new plug, valve adjusted, new oil, new filters, rebuilt carb, new battery, etc, etc. I had it running fine until the other day. When I turn it on sometimes the neutral light doesn't come on and I have to kind of jiggle the key for it to illuminate. The neutral light remains on and the electric start works fine, the engine turns over just great, and I have compression, but it will not start. I checked to make sure it's getting fuel and even sprayed a bit of starter fluid in the carb to see it'd turn over, and I got nothing. I'm assuming it's a spark problem, but I'm not sure how to fix it. I checked the wires to the coil and they are OK. Any ideas? I really want to get this thing running again so I can take it out and enjoy it.

I printed out the wiring schematic so if I get a chance I'm gonna check out the wiring harness.

[hublake]

Try a new spark plug.

[code200k]

is it getting spark at all?

[brapp]

check the neutral switch it son the the botom of the motro just belos the edge of the clutch cover ther eis a small tim plate and it covers the reverse and neutral
(sensors) but if the neutral switch or wir eis loose or disconected you wont get spark this is a fairly common problem and have personaly had it happen at least 2 time sach on both my sx's

[Twilight]

did you check for spark?

[Erics350x]

Pull the spark plug and plug it into the wire, lay it on the head and crank it over while watching for spark at the plug gap. Let us know what happens.

[zainyD]

Pulled the plug, hooked it up to the wire and laid it on the head, nothing, no spark.

Checked the wiring harness and everything looks good.

Checked the reverse/neutral sensors and made sure they were properly plugged in and clean. I get immediate illumination of the neutral and reverse lights now, but still no spark.

The plug wire boot has a tear in it that I repaired, and I really don't think that's the problem. It ran fine before now in the same condition.

I just put a new plug in it a month ago and it has less than an hour of riding time on it since then. I did notice that it had some carbon on it though. Cleaned it up and tried it again, no spark.

I'm getting fuel, I double checked on that today, compression is still good. Cranks great, but no fire.

What next??? Just to let everybody know I am a complete idiot when it comes to anything electrical. If it's mechanical usually I can figure it out, but electric related items are a complete mystery to me.

[POS 250sx]

Ive got an 86 sx and my ignition went bad causing similar problems. It would not quit once ina while and i had to jiggle key like you said to shut it off. It finally died out in the woods i jiggled, and top half of ignition came off. When you turn the key it aligns 2 sets of poles with each other, off aligns the "kill" poles and stops spark, when key is on other 2 poles line up and send power to headlight and starter switch. Cut the "kill" wire and kick it over manually, if it starts, u need to re-soder that wire, and buy a new ignition. If it still has no spark, then you resoder that wire and I look like a *Edited**Edited**Edited**Edited**Edited**Edited**E dited*. My headlight starter and dash were all broke so I threw it all away and wired a kill switch and new headlight switch, (to my new dirt bike head light) and mounted them on my new aluminum dash lol.

[zainyD]

I'm too embarrassed to say what the problem was, but lets just say it was something that was stupid obvious and I should have checked first thing.

Thanks for everybody's help the trike's running great!

[firehart]

Sounds like he forgot to check the kill switch. I've done that before on my Rancher.

[hublake]

I'm too embarrassed to say what the problem was, but lets just say it was something that was stupid obvious and I should have checked first thing.

Thanks for everybody's help the trike's running great!

Don't feel bad. I did the same thing once. Couldn't figure out what the heck was wrong. Took it to a repair shop and they fixed it real quick.