Isopropanol definitely isn’t the same as petroleum naphtha…

You are absolutely correct. I don’t know what I was thinking.

I’ve helped folks on the water before, however, I’m not out there looking for someone to help. We’ve all seen the guy at the ramp, in everyone’s way, his boat won’t crank, then finally it does. And he’s still having problems at the dock when you launch and head out. If I happen to see this guy broken down out on the River/lake I may or may not have time to help. Life or death, no questions asked I’ll help, other than that and he’s probably on his own since his dumba$$ should have known when he left the dock that he probably wouldn’t make it back.

7x57, those folks should have helped you, especially with you having a kid in the boat.

I aint ever left somebody stranded on the water..i was raised on the deck of a boat an that was about the first thing i ever learned..leavin somebody on the water aint the same as on land..theys turds an low lifes on land and sea..but as my daddy said bullets an ropes can be thrown from afar

Well just to tie a bow around all this after letting the boat sit in the garage for a week while out of town may have actually helped in the de-carbonization process. I pulled the plugs, wire brushed them, and re-gapped them. Then I pulled the silencer assembly off the carbs, hit it with a little starting fluid, and she fired right up. The amount of smoke that burned off was amazing. People were stopping and looking, haha. I was afraid someone was going to call the fire trucks.

Took it out to the river yesterday and it's running like a top again. So, glad I didn't kill anything. It's due for lower unit maintenance so when have that off I'll probably go ahead and check the fuel pump out, new plugs, and try to get the carbs balanced a little better.

Killin' skeeters:

Good deal

Looks like my small engines after a PB Blaster LMT treatment at the 1st of every spring.

Glad to hear she fired up for you and is running good again!

I would replace the fuel lines and change the spark plugs then check it.

glad u got it going.

I can smell that picture and it makes the hair on the back of my neck stand up. That's the good stuff

How old is that motor?

2007 70TLR, 6H3K, L, 1006XXX

glad you got it going, but just a small fyi, never ever use starting fluid on a 2 stroke boat engine.

I use a shot of carburetor cleaner instead of starting fluid, but if the air temp is below 40 my Yamaha 50 hp ain't cranking unless I spray it with something. The thing doesn't have a real choke on it, and the prime start system must have been designed by a sadist. Why couldn't they have just put a real choke on it?

It runs great once it warms up and will keep doing it all day. The tiny bit of carburetor cleaner does what the prime start is supposed to do, but my theory is that it just doesn't put in enough fuel to crank it when the weather is cold. I could be wrong.

I wasn't going to post any more updates, but I was running back to the boat ramp Saturday night after deer hunting and she ran great at WOT, but wouldn't idle worth a damn. I messed around with it on Sunday, but never felt confident in the idle. So, I decided to pull the carbs and rebuild them. I have #2 torn down and soaking in B-12 chemtool right now. Going to do one at a time while I wait for rebuild kits to get here. I'm also replacing the fuel pump while I'm in there. I checked the fuel bowl on #3, and it did have a little bit of sediment in it, which I would expect since it's at the bottom, but it wasn't a lot.



PCP, I thought my problem might have been the Prime Start system, so I pulled it and metered it. Ohms were within spec and it did extend over a few minutes like the service manual says. Needle looks good and not banged up. Gaskets and diaphragm looked good as well. So I'm pretty confident the Prime Start isn't the problem. So much for an easy fix.

Skintback - I didn't know you couldn't use it on 2-strokes, but I will be sure not to from now on. Makes sense. If the problem was a no fuel condition, that would mean no oil either. So then you're running off starting fluid with no lubrication.

As an aside, if I keep working on all my own vehicles and stuff, I'm going to have to make sure my hands don't smell like grease once I become a dentist according to my wife.

Pull the thermostat and see if it's stuck open.....

You thinking maybe thermostat stuck open on a colder night = colder engine = worse idle?

Air temp was pretty warm, but water temp was in the 50s I think on Sat.

I have it's cousin , a 40 Yamaha. Same behavior. I gotta go to 4 cycle soon. They will soon make us anyway.

I'm gonna run mine until someone from the government comes to the house and removes it from the boat.