Evinrude 65hp ( 1973) Fuel problem

[foxster]

I appoligze for getting the first forum all messed up.But Iam new to this site and looking for opions on this problem Iam haveing with a 1973 65hp Evinrude.Please note Iam new to boat motors but trying to learn.Here's the problem!The motor runs fine when it wants to,but it comes out of the hole slow and takes time to build up to top speed,when it gets to top speed,it will run fine for an undertermined amount of time or distance and all of a sudden it will act like it is starting to lose power and will surge,Sometimes it will kill when first putting it in gear.Once in awhile we can sqeeze the primer bulb and make the motor come back other times it will just containue to lose it's power and die.Here's what we have already checked.The compression on all 3 cyl.read 110 psi with no vairation between them.The spark is good and bright.We have rebuilt the carbs( Hard to screw these up as they only have about 5 parts and everything is pre factory set)Floats also check out fine.We have replaced all fuel line hoses,with new ones and have put in a new fuel pump kit,We have double checked the fuel mixture 50:1 This is about all we know! However some days this motor will run all day with no problem but when we really need to count on it to preform well- that is when it starts haveing it's trouble.We're running out of ideas,and things to check.We would Greatly Appreciate any help anybody could send our way,for where we live there is no such thing as a boat shop or a mechanic.Thanks for your time -- Foxster

 

[fireman57]

Re: Evinrude 65hp ( 1973) Fuel problem

Did you check the spark when it was losing power or just on muffs?

 

[foxster]

Re: Evinrude 65hp ( 1973) Fuel problem

Fireman 57 No like I said,Iam a new fly by night motor want-a-be fixer.I haven't checked the spark except in the driveway.( I live quite a ways from water) But I read what you said to TR 918 who seems to have somewhat of the same problem.So I will do what you told TR to do.However!Me looking for someone who has any motor testing equiptment,where I live,would be like looking for a needle in a hay stack,Most people around here can't even spell boat motor,and a boat shop?This ain't happin.I really live in the middle of NOWHERE!But I appreciate all the help you can give me ( Many Thanks) I'll be back on the board after I manage to get to the water and check things out a little.Problem is:Like everyone else I leave the place and the sun is shineing,I get to the water and it may be hailing.But I'll be in touch,many thanks again

 

[rkaib]

Re: Evinrude 65hp ( 1973) Fuel problem

Does it only happen when the gas tank is about 1/2 a tank? Does the primer bulb suck together? If so check your pickup at the tank or the antisiphon valve locate in the same area. If you have a portable tank try using it to determine if the problem is on the boat and not the engine. If it runs fine on the portable gas tank the problem is somewhere on the boat. Could also be the primer bulb sometimes the valve in the bulb can get stuck.

 

[reddog349]

Re: Evinrude 65hp ( 1973) Fuel problem

I have a 1977 70 evinrude and I had a very similar problem. Foxster- Check your vent !!!! My engine would run fine for a long while -unitl the vent got plugged up and cause the same problems.

 

[foxster]

Re: Evinrude 65hp ( 1973) Fuel problem

I also thought that my problem might be the tank or in it the motor is setting on a 14ft tri-haul and has a portable tank ( plactic ) I tired a metal tank I had and it was the same.I changed tha primer bulb and hose.when it starts to lose power at wot sometimes we can hurry to the back of the boat and pump the bulb and the motor will come back and run again for an undertimed amount of time ( maybe for a 1/4 of a mile orr shorter or longer just whenever it feels like it is time to screw up and if we don't get to the pr4imer bulb in time it will just die and then when we start it again and try to get going sometimes it will just die when we put it in gear.If it does go again without dieing it is slow to come out of the hole and takes time to build up to full speed,once up to wot it will run Great until it decides it just don't want,then it acts like it is loseing power( If it was a car I would expect a dirty fuel filter.I am going to check a few things once more with the fuel supply and then start checking some things that fireman 57 told tr-19 to check. As somewhat the same problem I seem to have .But I do really apperciate any help any of you can give.Thanks alot

 

[tr918]

Re: Evinrude 65hp ( 1973) Fuel problem

Foxster, Mine did act like this before it died but never responded to squeezing the primer bulb. My problem is purely electrical. Do as Fireman57 said. Check for spark at WOT. Pull the plug wires at WOT and see if the rpms change. If they change the spark is ok. If they do not change you are losing spark to that cylinder. This will will help to determine whether or not you have a fuel/air problem or a spark problem. In between visits to the water check all fuel lines, including the ones in between the carbs for hole/leaks. If it responds to the squeezing the primer bulb it may be a fuel/air leak. You need to find out for sure. Good luck.

 

[fireman57]

Re: Evinrude 65hp ( 1973) Fuel problem

If you can get it to respond to sqeezing the bulb two or three times then rebuild the carbs if it hasn't been done in a while. You can also check your fuel pump. Since you are a good distance from water do a search on how to check these things so you can do them all while you are there. You don't want to just start throwing dollar bills at the problem. Systematically check this stuff so we will have the results when you get back and can narrow it down.