take the stator side cover off and look at the magnets. make sure there ain't no surface rust on the pick up magnets.

 

Ah, that reminds me. This may be fairly important..
When I first got this thing I bought a new battery for it. I filled it up, charged it up, hooked it up and when I turned over the engne (electric start) POP! Blew a fuse. So I find that both betteries look exactl the same but the + and - were swapped so ihad charged it wrongand connected it wrong. I replaced one blown and it seemed to charge and crank okay.
After that my buddy told me my stator would be f'd so on impulse I bought a used one on ebay and haven't put it in yet. Maybe ill try that, I better find out soon I probably only have lik 5 days to return it

 

WOW, can i ask how you hooked'em up backwards? positive to solenoid/starter and black/ground to frame. hmmm...what did the previous owner do? jack it all up? hmmmm....let's get you stator checked out. glad it jogged your memory. now we're onto something...hopefully, if that impulse is fried, it didn't get your ignition coil.

 

Haha, well im not quite as dumb as that mistake is. Its not like I rewired it in reverse polarity, I used the existing positiveand ground cables that were there and they were very tight so the new battery terminals lined up perfectly.. I just connected them but they were reversed.
So, ill slap in this new "fully functional" used stator tomorrow and see what happens.

 

My money would be on the source coil... #2 in the diagram 1985 Yamaha Tri-Moto 225DX YTM225DXN Parts, 1985 Yamaha Tri-Moto 225DX YTM225DXN OEM Parts - BikeBandit.com

Anytime something this old doesn't run when hot, suspect a coil and the coil in the oil is going to get hottest. Though considering the age, all the coils are going to be weak.

An ohm test on the coil is probably going to be misleading. I've seen a few check out, but were at fault nonetheless. You might test when cold and compare it to a test when hot. If there is a big ohm difference, then that could be your problem.

I'm guessing that the lighting coil supplies current to the battery, which powers the lights and starter. The source coil supplies current to the cdi and ignition coil. The design looks like something that used to be without a battery. Usually don't see source and lighting coils in battery driven applications. You see the 1986 Yamaha Moto-4 225 stator is entirely different 1986 Yamaha Moto-4 225 YFM225S Parts, 1986 Yamaha Moto-4 225 YFM225S OEM Parts - BikeBandit.com If that were your case, then I would be more likely to suspect the ignition coil.

 

Any luck with the new "fully functional" used stator? I am looking at a similar problem with something of mine and was really considering purchasing one on line this week.

 

So what is your similar problem not starting or not idling?
Well anyway here's an update:
Got it to start the fuel line was pinched when I took the gas tank of to find the ignition coil (not sure how to test it any advice?)
Put the used functional stator in (which looked exactly like mine) and started her up.
Rode around for a bit but this time, the idle screw on the carb makes a difference.. only to lower the idle speed it won't raise the idle speed cause it won't idle!
I have before noticed that every once in a while it would actually idle but when it did it would just rise and rise and rise before I shat my pants after my eardrums were shattered and id just shut it off. The next startup would be just like normal (not normal as in runs normal but normal as in ITWONT IDLE!)
So, turkey to answer your question- new stator makes no difference for me, but if you do decide to purchase one, make sure you get a new gasket for it because I didn't and mines leakin oil like crazy until I can get a new one.
Tomorrow I'm getting new jets so we'll see how it goes ill keep this updated.
Thanks for readin,
Jacob

 

I was asking in regard to the hard starting. I read above from Jaster94 about rust on the magnets... I have plenty of that. Good luck on the new jets. Keep us posted. I am learning along with you from these other guys!

 

Good to know there's somone else here with the same bike as mine, I bought this for 244$ and I've been sort of restoring it. Actually this may have helped me come to the conclution that this has to be carb related because it ran fine when I got it just until I took th carb apart to clean it.. I'm thinking now these jets will do the job

 

Yesterday was about 20 degrees here. I put a gaset on the stator and new oil in. I dumped a little seafoam in the gas tank a few days ago too. So I start it up and its idling! But very high. I adjust the idle to where it should be and I was shocked, stator did it sweet. Let it idle for about 5 minutes until the oil that splashedon the exaust started burning away. That's when it got warm and started mumbling down to its death. So I let it die, and it wouldn't start, unless igave it gas.. then it'd start just fine and run without an idle. That points me directly to the carb, which I should have looked into first. It better be that pilot jet. I bought a new one and will post the results after I put it in. And since its running rich I got a main jet one size smaller, the yamah dealer didn't have the original size in stock so I didn't think bigger would do me much better.