1967 115hp johnson running problems

[rosgood14]

i have a 115hp johnson that when i run it on land with the water hose it runs great other than a few sputters. the first time i put it on the water i had started it earlier that day and it ran fine, but when it got to the river it did not want to stay running at all. the second time i took it out i started it up backed it off the trailer, drove around a minute came back and picked ppl up. we took off made it about 100 yards and then it died and just would not stay running. i could start it back up and the minute i put it in gear it died. i can bring the boat right back home and hook it up to the hose and it will run fine wether it be idiling or in gear. i am at a complete loss. plz help me. thanks

 

[tashasdaddy]

Re: 1967 115hp johnson running problems

set your idle at 1100 rpms, on the hose. then when you get to the water, set it between 650-750 rpms, in gear forward or reverse. the idle has to be set in the water, and in gear. this is the only way to keep it running. the reason is on the hose there is no backpressure on the exhaust.

 

[rosgood14]

Re: 1967 115hp johnson running problems

how can i set the rpms because i do not have a rpm guage on my dash. its an old boat. Also when i took the boat out last time it did run long enough for me to back it off the trailer and pull it around to the dock. could it still be the backpressure on the exhaust even though it ran just fine then.

 

[tashasdaddy]

Re: 1967 115hp johnson running problems

you want to set the rpms as slow as you reasonably can and the motor not stall. need to know if it would restart, what have you checked, spark, compression, did it set up for a long time, and just started using it.

 

[rosgood14]

Re: 1967 115hp johnson running problems

so once i set the rpms as low as possible you need to know if it will restart. is that correct. i have checked the spark and it is getting good fire. i have not checked the compression. how do i do that exactly. also as far as i know the boat did not sit for a real long time but it might have sat for a little while. the previous owner had planned on restoring the boat but never got around to it, but it fires up with no problem.