First Boat Need Help 1979 3 cyl Evinrude

[tazzster0228]

Hello,
I have a 1979 70HP 3cylinder Evinrude i bought used I hooked everything up to my boat it has power tilt and trim. Only thing didnt hook up is the plug for tack and i think it is for temp too. Guy i bought off of didnt have it hooked up either. It runs perfectly out of the water when hooked up to a set of muffs on the water hose. It runs excellent at idle and cranks right up but once u get to mid throttle and start to wide open it bogs down and will only pick up too half speed. I put new plugs and new gas in tanks. I have tried the pushing the choke on when it starts to bog and it will pick up a bit. I took it out and had my buddy to throttle all the way open and i went to the motor and held the choke about half way and it will pick up really well. Could someone tell me what i should do next or how to have it fixed. Thanks Jonathon

 

[JDP]

Re: First Boat Need Help 1979 3 cyl Evinrude

I had the same problem with my 115 when I bought it. The problem ended up being the fuel pump. You can get a rebuild kit pretty cheap but I just bought a new fuel pump. Hope that helps

 

[tashasdaddy]

Re: First Boat Need Help 1979 3 cyl Evinrude

using the choke points to fuel starvation, causes, 1/ dirty high speed jets in carb, 2/ air leak in fuel line, 3/ fuel pump, 4/ vent not open on gas tank. did you try pumping the bulb, that would lead to fuel pump. do not rev over 1500 rpms, on muffs, can damage the motor.

 

[tazzster0228]

Re: First Boat Need Help 1979 3 cyl Evinrude

Thanks everyone for the information. I think i will start with the fuel pump, I did swap lines cause the other fuel bulb would not stay hard. I did try pumping the bulb but didnt make a difference.

Thanks again.

 

[tashasdaddy]

Re: First Boat Need Help 1979 3 cyl Evinrude

the bulb does not stay hard when running. it's just to prime the pump, and fill the carb bowls, now it it won't get hard, it means the carb float needle is stuck and not closing. if pumping the bulb did not make a difference, it is not the fuel pump.

 

[tazzster0228]

Re: First Boat Need Help 1979 3 cyl Evinrude

what i meant by the bulb was the other bulb would not get hard when priming after switching the tanks like the bulb was stuck. So should i lean towards having the carbs rebuilt. Im new at this but to me it dont make sense how it will idle perfectly in the water and run untill mid range then when u try opening it up it bogs and will only run at mid range. At first i thought the engine wasnt enough for the boat but everyone says it is fine. The boat had a 115 johnson on it when i bought it but it was hydro electric shift and the coils in the foot went out so i swapped it with the 70 Hp evinrude. The boat is a 1973 Ebbtide. 15 foot. I know it cant be much wrong with it cause we ran it on the lake yesturday and ran two tanks of gas out of it thinking it would clear out. Thanks again for everyones help.

 

[tazzster0228]

Re: First Boat Need Help 1979 3 cyl Evinrude

Also i would like to add that i did a compression check on the motor and it has 125psi on each cylinder. What spark plug should this motor take and what should be the gap on the plugs.

Thanks

 

[tazzster0228]

Re: First Boat Need Help 1979 3 cyl Evinrude

I want to think everyone for there help. I fixed the motor. I had a bad bulb on the fuel tanks and all three carbs had old gas that had sit and gooed up in the jets. Had the carbs cleaned and wall la. Starts and runs just like a brand new one. I do have one more question. What ratio of gas and oil should i run in the motor the sticker on the motor says 50 to 1 i was just wanting to make sure that was correct. Again thanks for all the help.

Jonathon

 

[The-Machinist]

Re: First Boat Need Help 1979 3 cyl Evinrude

Its usualy a good bet to trust the manufacturer when it comes to stuff like that. by the way,50/1 is what you need.

 

[tazzster0228]

Re: First Boat Need Help 1979 3 cyl Evinrude

Thanks for the information also I got one last question. How can i find out how many people can fit into this boat. The metal sticker that shows all of that is all wore off. It is a 1973 15 foot ebbtide from Tennessee NC I would like to know what the maxium weight and all would be and i should be ready to take the first step which is to launch and fish. I done been reading the mishap section. Which I will be posting in probably before it is over. LOL

 

[tazzster0228]

Re: First Boat Need Help 1979 3 cyl Evinrude

Also one more thing where can i get a new prop and how do i know what to buy.