Motor slowly loses power

[purplerain810485]

1963 Evinrude Fisherman 5.5HP<br /><br />What will happen is I start it right up..Then after running WOT power for a few minutes it'll start running slower and slower until I'm moving like I'm at half throttle. Is it overheating? It's peeing good (well actually this motor dosen't pee a stream..it kind of gives a strong sputter, always has). Any Ideas?

 

[fireman57]

Re: Motor slowly loses power

Sounds like a coil breaking down under a load. Check for spark. To check for overheating you should be able to hold your fingers on the head for a slow 3 count before you jerk them off and yell ow. You also could be picking up some crud in your high speed jet.

 

[purplerain810485]

Re: Motor slowly loses power

how would I check for spark? If it's in the factory manual just tell me..becuase mine will be here tomorrow. I just took it out again real quick and it ran like crap! after shifting into forward and giving it WOT..it took like 5 seconds for it to start moving good. This time it bever really started good. Ran like crap from the beginning. Then it went from crap to worse and just went slower and slower until it died. Started right back up and I brought it in.

 

[purplerain810485]

Re: Motor slowly loses power

I just went out to flush it becuase it was out in the salt earlier..and the idle was very erractic for the first minute and then it settled down and idled good..anyone know what all these problems mean?

 

[fireman57]

Re: Motor slowly loses power

Could have had crud in a jet that cleared. If you want to check the spark then pull a plug wire and see if it will jump a bright blue about 3/8 to 1/2 inch. Make sure you use insulated pliers or a brother in law.

 

[danny k]

Re: Motor slowly loses power

Sounds like electronic overheating or breakdown or carb(or fuel) problem. This post is interesting, please keep us posted.<br /><br />Danny K.

 

[purplerain810485]

Re: Motor slowly loses power

I will, my service manual (ken cook factory) comes today and I'm going to start troubleshooting with what I've been told here and with the manual.

 

[SuddenImpact]

Re: Motor slowly loses power

i had the same problem with a 1990 48hp...changed the plugs to ngk with an electrode..and ran some seafoam in the gas mixture..1oz. per gal and no more problems..however now i don,t no what fixed it...

 

[purplerain810485]

Re: Motor slowly loses power

there's spark..that hurt

 

[Solittle]

Re: Motor slowly loses power

I would replace the water pump and rebuild the carb. Both are preventative maintenance jobs and relatively easy to do.<br /><br />Have you determined if it is overheating or not?

 

[purplerain810485]

Re: Motor slowly loses power

well I took it out and ran it for awhile and then splashed water on the head..no sizzle at all. I don't think it is overheating.

 

[brehlers69]

Re: Motor slowly loses power

Its got to be the fuel pump. does it fix the problem if you pump the bulb. try that if it fixes it its your fuel pump for sure

 

[purplerain810485]

Re: Motor slowly loses power

fuel pump checks out..pumping primer didn't change anything..what's next? Rebuild the carb?

 

[Solittle]

Re: Motor slowly loses power

dan - Ahh the "sizzle test" - - I think OMC would recommend that you use temperatur sticks instead or put you fingers directly on the heads. If you can leave them there for several seconds you are probably OK.<br /><br />My earlier comments still stand.<br /><br />Your motor does not have a pisser - they came out much later.

 

[purplerain810485]

Re: Motor slowly loses power

I did the finger test too..I could keep my finger there for atleast 4 seconds. I have two questions too. You said to rebuild the carb and replace water pump. I know I need a carb kit..but would I want to get a Needle & Seat kit too? About the water pump, I've been looking but can't find a water pump for my motor. It looks like Sierra dosen't make one. Where would I get this, and other parts? I have heard NAPA has Sierra stuff, so I should be able to get the carb kit (and any other thing made by Sierra I need in the future) there right? I guess I'll need to find a local motor place for other things then. Thanks for any help.

 

[purplerain810485]

Re: Motor slowly loses power

^ bump ^

 

[purplerain810485]

Re: Motor slowly loses power

bump

 

[fireman57]

Re: Motor slowly loses power

Yes, NAPA is very good at getting OMC parts. Needle and seat should come with the kit. NAPA can tell you what all comes with it.

 

[angus63]

Re: Motor slowly loses power

Hey Dan<br />You are mixing this machine at 24:1, correct??<br />32 oz oil to 6 gallons of fuel<br />You do have the fuel tank vented, correct?? Is this a pressurized two line system setup or basic single line?<br />Have you tried another tank and line?<br />Just checking the basics before you dive in deep.<br />Good luck

 

[malagaoth]

Re: Motor slowly loses power

glad some mentioned cheching the air vent! look at the cheapest thing first