classic 50 issues

[raray1221]

i have a merc classic 50 45hp and about a month ago started working on it due to bad idle. i cleaned and rebuilt both carbs and it ran the same. so i figured the idle must be too low. i adjusted the idle mix screws out and out beyond 1 and a 1/4 turns and no reaction. still low idle quickly ending in the engine stopping. finally a started adjusting the idle screw on the throttle arm and turned it WAY up. made it idle okay but still dies some. i am thinking that adjusting the pin on the throttle arm may be simply masking a real problem. Any suggestions on this issue? as of right now the engine runs excellent and idles crappy, mixture screws are both out 2 turns and throttle arm idle screw is way out. what should i check for as far as other problems causing all this.

 

[This_lil_fishy]

Re: classic 50 issues

reset your carb settings to baseline. Then try adjusting your floats. It could be flooding out at idle causing your problem. It took me a couple tries to get it right the first time I rebuilt my carbs. Also be sure to change the floats and needles if they are those foam floats or needles with the rubber black tips.

Otherwise you could have a weak spark at idle. Which will require a full ignition test which others here could help better with.

Ian

 

[raray1221]

Re: classic 50 issues

ok, the floats are plastic and should be set correct as the man who helped me is a mech. could a small air leak or hose problem cause these symptoms? i sometimes feel like there is something wrong whith the primer bulb hose from the tank. Thanks for the reply!

 

[This_lil_fishy]

Re: classic 50 issues

No idea, fuel pump or possible bad primer bulb, or ingition problem. You'll need to get that mechanic friend back to help a bit more.

ian

 

[raray1221]

Re: classic 50 issues

lol, yea probably right. Another question for you or anyone out there. I have a 45 hp but really dont feel like it is pushing my boat is fast as it should. i am going to put a "whales tail" on it and see if it improves at all, any other reasons i may be losing some horsepower?

 

[raray1221]

Re: classic 50 issues

ok, new problem. Engine idles fine out of water on muffs. Then backpressure on the exhaust when in the water causes it to not idle well. Not anything electrical, or at least all 4 cyl. are getting good spark. What should i do or what could the problem be?

 

[raray1221]

Re: classic 50 issues

btw, both carbs are clean and when i tried to adjust them from 1 and 1/2 turns the problem did not really change. got them out to like 2.5 turns and still dying. cleaned both. i did turn the throttle WAY up on the throttle arm and that helped but im thinking that is simply masking a real problem. PLEASE HELP!!