Johnson 115 starves on take-off.

[papag8r2]

I have a Johnson 115HP on a 15ft Jason Bass Boat. It starves for fuel on take-off. I know this is the problem because, I have to push the choke to get enough fuel to the motor when coming out of the hole. The Carbs have been rebuilt and the fuel pump is new. Can anyone tell me what the problem is or how to correct it. Thanks

 

[crazy charlie]

Re: Johnson 115 starves on take-off.

This may sound off the topic but have you done a compression check?????I had a similar problem that i was sure it was fuel related and i was wrong.Charlie

 

[JB]

Re: Johnson 115 starves on take-off.

Moving to Johnson Troubles.

 

[R.Johnson]

Re: Johnson 115 starves on take-off.

After rebuilding the carb's, did you do a sync. & link? is the idle pick-up timing set correctly?

 

[Yepblaze]

Re: Johnson 115 starves on take-off.

Just because the carbs have been rebuilt does not absolutely take them out of list of possibilities.<br /><br />It still might sound to me like it could be obstructed jets. If the fuel has been of poor quality it can still be problamatic till it's all flushed with and fresh/clean.<br /><br />Clean or replace any fuel filter. <br /><br />Make sure there's no water in the float bowls. Remove jets, closely inspect, and probe to make sure any hardened deposits do not remain.<br /><br />Check the fuel pump by giving a mild pump to that during take off. If no improvement then pump is ok. (for now)

 

[papag8r2]

Re: Johnson 115 starves on take-off.

Thanks for the replies. No, I haven't checked the compression. It would seem to me though, that if compression were the problem it wouldn't make a difference when I push the choke button. But, then I know very little about boat motors and will try anything to find the problem. After all the engine is an 86 model so, compression may very well be the problem. Lord what I'd give to have my Mercury back.<br />papag8r2

 

[papag8r2]

Re: Johnson 115 starves on take-off.

Thanks again Guys. It sounds like maybe I had better take it a boat engine mechanic to have it thoroughly checked out and repaired as necessary. I did have to unplug the jets and the float was properly set according to the info I got from a mech. I can change out the gasoline and add fresh and clean the bowls again before trying it again. Again the fuel pump is new. I do understand that it is man made and can have problems even when it is new though. I have been down that road with points on a caddy engine before. I'm just hoping to get it straightened out before the weather warms and I get the fishing fever any worse.<br />Many thanks for your replies and God Bless,<br />papag8r2

 

[papag8r2]

Re: Johnson 115 starves on take-off.

Oh, also I did change the fuel filter after rebuilding the carbs.<br />thanks again.<br />papag8r2

 

[Boilermaker]

Re: Johnson 115 starves on take-off.

Just a thought, but how are your fuel lines, primer bulb, and fuel tank??? I would be checking all of them for a problem. I saw a boat that had a very small hole in the pickup tube in the onboard tank, and it only showed up when the tank was less then half full & on a holeshot. The bow up attitude and high fuel demand caused a lean out condition.

 

[papag8r2]

Re: Johnson 115 starves on take-off.

Thanks BoilerMaker,<br />Thats a possibility. I tried to find a fuel pick-up but was told they couldn't get a new one for this tank. May have to change tanks to help. The line and bulb is new as well as the filter and all the lines around the carbs and pump.