Need your motor expertise

[mrfish11]

Well, we finally figured it out and fixed it. HUGE THANKS to @Walker Inc. and Kerry Allen for helping me narrow in on the ****STATOR*** after I tried replacing every other part on this motor. I just got back from the lake and shes purring perfectly again with zero surging. Keep those battery terminals clean because Kerry told me that is the main reason stators start to go out. Here are a few pics of what a fried ass bad stator looks like vs an OEM new one. The job is pretty much a nightmare but if anyone ever needs help with it let me know. I found a cheap flywheel puller and could probably do it again in an hour or so now that I know exactly how to get to everything. New stator is $650 ish and I did the intake manifold gaskets for $100 ( holy shit $100 for 2 little rubber band looking gaskets) since that has to come off to get to those 4 green wire clips. Sure hope this post will help someone in the future because this one has been a nightmare for me.

 

[PSULion]

Kudos to you for learning and then doing the work yourself. Like many here, I can do virtually all the usual servicing and troubleshooting but this is next level DIY repair. I would have been forced to hire this one out and sit at the dock for ?? weeks.

 

[Tomictime]

If you are going to use this approach to find a vacuum leak it is better to use a spray bottle with water in it. If there is a vacuum leak the rpms will change when the water momentarily clogs the leak and there will be NO CHANCE OF FIRE!

Crocs are mostly fireproof….

 

[gonzo25]

Now that ur a certified engine mechanic Brian, please swing over here and tell me why I'm sucking air in my Yamaha 2 stroke every now and then... But seriously - I hope that is the ticket and you get back on the water!

do a leak down test... best diagnostic for 2 stokes, you can check internal seals. listen for air leaks, wd40, soapy water for the obvious places

 

[Captain Decent]

I would have never suspected the stator. Good work. I’ve replaced stators before but they were both out. Interesting.

 

[gonzo25]

I would have never suspected the stator. Good work. I’ve replaced stators before but they were both out. Interesting.

I was thinking the same thing. especially at idle I would think the battery would have enough in it that it wouldn't be noticeable until it started turning more rpms, especially when these motors only run on 2 cyl. until about 2000 rpm. But one of the things, going by the book, your supposed to do is check that the battery is fully charged.... of course I am the worst for that, I always figure if it will turn it over and start it should have enough power for it to run since it doesn't take much after it is started, but it makes sense if the stator or the rectifier isn't working right that would do it. So your not alone it would have taken me a while to come up with that.