Johnson 4hp Seahorse, wont rev up properly and awkard start.

[allymoss]

I have recently aquired a 4hp johnson seahorse. I am happy with it until today! It ran in tanks several times and was fine, revved up quite bit.

Now the first time I take it on a boat, it takes ages to start and then when running, it will not rev up much. When I engage the gear, it goes fine but wont rev up. If I push the throttle up too high, it cuts out.

I put new plugs in, I took carb off and soaked in carb cleaner. Any ideas?
Prop is slightly broken and new one is on its way to me but that isnt a problem as it wont rev up even out of gear.

I also have another 4hp johnson. Slightly older, 70's I think. It runs ok when going but starting is really hard. From cold I have the choke full on and it revs up but dies instantly. I keep trying to turn the off a bit before it dies but it takes me ages to start. I havent cleaned this carb yet. When running, it is fine and starting from hot is easy, but as soon as I leave 5-10 mins, it wont start easy again. I have to get it running a bit and then slowly fade out the choke then its fine. Any ideas on this one?

 

[allymoss]

Re: Johnson 4hp Seahorse, wont rev up properly and awkard start.

Also, on the first motor I talked about the one that wont rev up, there is a mixture knob. Where should this be set. I was told to scre it right in then unscrew it 2 revolutions. Is this correct?

 

[tashasdaddy]

Re: Johnson 4hp Seahorse, wont rev up properly and awkard start.

go to the engine faqs forum there is post there for carb adjustments, sounds like carb cleaning is in order, also a compression check.