idles great in driveway, not so much in water

[melvino]

I have a 74 Johnson 50 hp which is pissing me off. It starts and runs ok when I have muffs on it in the driveway. When I put it in the water, I can barely get it started and it will die unless I have the throttle lever all the way up. I put the lever down to shift it into gear and it dies of course. I had a guy look at it and he said it needs to be rebuilt. I dont have the money and I just want to make it through the summer. 1. Why does it run differently in the water, and 2. Is there any easy way to up the idle speed? Any advice is always appreciated.

Thanks,
A novice 1st time boat owner

My father in law told me there are only 2 good days for a boat owner. The day you get your boat, and the day you get rid of your boat!

 

[jonesg]

Re: idles great in driveway, not so much in water

Give us more information.
What did the guy say,

exactly why does it need rebuilding.?
He'd have to convince me.

Do you have a compression guage ?
and a timing light?

 

[INDYCAVER1]

Re: idles great in driveway, not so much in water

I just solved the same problem with my 72 85hp. Seemed like it ran great with the muffs, but in the water wouldnt rev over 2000 rpms with out sputtering or dying. I took my carbs off and cleaned out the bowls( which were still gummed up,even after running out of gas before i winterized it) and now it runs great. My high speed orfices were pretty dirty and not flowing enough fuel to keep it running under load in the water. I used seafoam first, but it didnt quite get it all cleaned out. I had to do it by hand. Now she runs like a champ. It just a suggestion, im still a ametuer at the boat mechanics, but I hope im learning from working on mine and talkin to others.