1975 Johnson 25HP won't fire

I recently added a creek boat to the fleet. When I went to look at the boat the seller stated that he had rebuilt the carb and I saw the motor run. He stated, and was correct, that the motor ran rough when cold. So I bought the boat. Fueled it up with ethanol free mid grade, added starton (just to be sure) and 2 stroke oil. Took it out to the Goose Creek reservoir for her maiden voyage. She fired at the dock and smoked a little. Ran a bit rough, but it smoothed out after a few minutes. Ran across the lake about 200 yards and the motor died and would not restart. Got it home and pulled the cover. New plugs (were wet when pulled). Tried the starter and had spark (only checked the upper). I pulled the fuel line and had fuel coming through ok. I did have a vacuum on the fuel tank and didn’t have the vent open enough on the plastic tank. I tried to start it and it still didn’t fire. The motor appears to have fuel and spark. Any thoughts or ideas? Thanks.

21’ Sea-Pro CC
Yamaha 150
“Aquaholic”
2008 Dodge Ram Mega-Cab 4x4 6.7 Cummins

“There is no hunting like the hunting of man, and those who have hunted armed men long enough and liked it, never care for anything else thereafter.”
Ernest Hemingway

Hey man. I just sent you an email.

please visit
http://norml.org/

If you ain’t retie’n, you aint try’n…

See Tex, shoulda bought mine!!:wink:

Sorry to hear your having troubles, though…
Check the compression before you do anything else.
Otherwise, would prob be the prior carb work for next consideration.

Lol. Prolly right there Salthunter. I fixed my problem. For whatever reason, dumbazz I guess, I forgot to loosen the vent on the plastic fuel tank. Motor was pulling a vacuum and at one point could not suck any more fuel out of the tank so the motor died. After loosening the vent and letting the tank “breathe”, she fires right up. I knew better, just forgot. Of course, I haven’t dealt with removable fuel tanks in 30 years and my last ones were steel and the vents rattled when you moved them. So when you picked the up to fill, you always knew they were vented. Lol.

21’ Sea-Pro CC
Yamaha 150
“Aquaholic”
2008 Dodge Ram Mega-Cab 4x4 6.7 Cummins

“There is no hunting like the hunting of man, and those who have hunted armed men long enough and liked it, never care for anything else thereafter.”
Ernest Hemingway

That sounds familiar…:face_with_head_bandage:
Glad you ‘fixed’ it!

Did some further testing and discovered that I had a bad coil. Good fire going in but nada, zip, zilch going out. That would explain why it was running rough. Got one on order and should be here in Wednesday. Updates to follow. Had a guy check the compression on Saturday, 130 on the top and 135 on the bottom. Good to go as far as overall condition.

21’ Sea-Pro CC
Yamaha 150
“Aquaholic”
2008 Dodge Ram Mega-Cab 4x4 6.7 Cummins

“There is no hunting like the hunting of man, and those who have hunted armed men long enough and liked it, never care for anything else thereafter.”
Ernest Hemingway