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Solenoid jump to start, WHY?

bjbrenden

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I have an '82 750f. The Solenoid, starter switch, main wire harness and rectifier are all brand new. Checked and cleaned up grounds, Fuses are all good, have power to the starter from the solenoid but the bike will only turn over when I jump the solenoid. When I hit the start button the headlight dims, but that's all that happens. I'm completely stumped.

Any help from anyone would make my day.

Also, my neutral light stays on no matter what gear I'm in. Related to starting issue??? or just annoying?
 
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Will it start if you hold the clutch in? And have you checked to see if you get 12V to the solenoid when you hit the start button? If so, you have a bad (albiet new) Solenoid.
 
Hey Zanthor, thanks for the info. It will not start with the clutch in. I just removed and cleaned the neutral switch, so the neutral light is working properly anyway.
Now, for the solenoid. I put my voltmeter on the pos and neg of the solenoid and hit the starter. my voltage actually went up about 0.25 volts when I hit start. If I understand you correctly this means I got a bunk part? I hope you're right because I've been going nuts over this.
 
I need to clean my neutral switch apparently :), that green light gets old.

The Solenoid has 2 places 12V should reach it, obviously one of the big nuts on top will have 12V, and when you cross that to the other one your bike cranks over... The other place is the line from your main fuse, that should have 0V when the buttons not pushed and should jump to 12V when pushed. If that's getting 12V when you hit the start button I'd say it's a bad solenoid.

For what it's worth, I pulled my bad solenoid and slammed it hard on a solid table and it became a good solenoid... for how long is yet to be determined :).
 
a solenoid is just a switch. it can always be tested using another solenoid and you can run a diffrent solenoid if you wish. it is only limited in creating a mounting and some wiring work. i use the solenoids for ford trucks now,but in the past i have used lawnmower solenoids.
i dunno how much stock replacements cost now but the mower and auto ones are usually in the ten to twenty dollar range.
 
http://www.vintagecb750.com/search/?q=relay <== $28, no need to fabricate a mount.

appears that the aftermarket is getting better now on these bikes. it has been a couple of decades since the last time i ever looked for a new stock solenoid and honda was the only available thing. i usually just keep engines and a few bits and pieces then eventually toss,trade or sell most of whats leftover.
 
Thanks guys. The company I ordered from sent a new one out immediately after I emailed them. Hopefully it works this time. if not, I'm getting a lawnmower solenoid and calling it good.

thanks again
 
Well fellas, here's the skinny. I put the new solenoid in and nothing changed. I chased wires and grounds around for a couple weeks. I searched and searched and started to get both pissed and bummed out. Then, yesterday, eureka. Clutch Safety Switch! The little bastard was destroyed on the inside so I threw it away and spliced the wires together and voila, no more clutch safety switch. The nice thing is I pretty much have new wiring everywhere.
thanks for the help guys,
 
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