So this one may be simpler to resolve. I have a 50cc Chinese quad that won't start. The starter relay clicks over, I have good power and ground at the starter and the engine is not seized up (push it in gear with the spark plug out and I can hear/feel the compression from the plug port). So, I replaced the starter. That did not fix it. I even went as far as putting a fully charged 12 vdc battery directly to the starter contacts to eliminate anything else and nothing...no engine turn over at all. What else could it be?

Any ideas anyone?
Thanks,
Roger

 

Lynn, for some reason, the PM messages we had going back and forth are now not showing up in my PM box. Are you seeing them in your inbox?

 

Yes, I'm seeing your PM's.

If you're comfortable with a public forum response this is a better way. No doubt someone else will come along with the same problem and benefit from the public exchange .

Just to be sure: Did you measure 12 volts right on the starter motor while attempting to crank. Red on the starter motor input post, and black on the starter motor frame. Any other location for the probes is inconclusive...

If you have 12 volts on the starter, and the engine doesn't turn, then there are only two possibilities I can think of:

1) The starter motor is bad. Since you've replaced the starter motor that would mean you have two bad starters.

2) The engine is too hard to turn.

Since you can turn the engine manually I'm wondering if there is something wrong with the mechanics in and/or around the starter clutch. The starter clutch connects the starter motor to the engine when the engine is stopped and the starter is turning. And it disconnects the engine from the starter motor when the engine is going faster than the starter. So if your starter is stopped, and you turn the engine by hand, the starter clutch section stays still. But when you run the starter motor (with the engine starting off stopped) the starter clutch mechanism is moving. Maybe it can't move for some reason.

 

Yeah Lynn, by all means lets start using the public posting I made for this as well as the Yamoto 250. I know looking at others "no spark" threads, I am getting more ideas to troubleshoot that Yamoto. I added some good T/S-ing info on there today, so when you get time, please have a look and let me know where I'm going wrong.

U R a freakin' genius by the way from what I've been reading so far.

So, back to the item at hand..........YES, I tested directly on the starter connectors for the voltage and also used it's ground for the meter so to eliminate everything else. Now, I had the cover off the left side of the case when I changed the starter to get the chain off/on the starter gear. Sounds like I need to remove that again and check the things you mentioned. But with that cover removed (which has the stator on it) will that affect my troubleshooting?

Roger

What did we ever do without forums like this......hahaha

 

So after a pretty successful day working on both motorcycles and the boat, I decided to press my good fortune today by messing with this 50cc again. I got it running............man, everything went my way today with every project I touched (and that doesn't happen too often around here).

I removed the stator to check and see if the starter chain was even tensing up from the starter and it wasn't. So I was pretty sure at that point the new starter I installed was no good. I removed it and using a fully charged car battery, connected the pos and neg and the starter started working just fine. So, I sat it aside and began messing with the starter clutch which spun pretty freely by hand. So, put it all back together and viola!!!! it turns over like a champ.....mmmmm........so, not sure exactly what it was in the end because when I first got it, it was doing the same thing......starter relay clicking, good power and ground at the starter......anyhow, who cares........it works.........rode it around for about 10 minutes....I need to do some adjustments on the carb....seems to be getting too much fuel I think.