71 25hp evinrude idle problem

[woodducker]

Hey guys,

I just recently acquired a 1971 25 hp envirude. And have done all i could think of to solve the idle problem. Soaked and cleaned carb., compression at 125 for both, good spark on both, new plugs, replaced fuel lines and fuel pump working properly, new tank and bulb. I can get it to idle by pulling choke in and out when it starts it bogs down and loses all power. It has lean rich knob that is not hooked up and im adjusting manually, could this be my problem? or is there any suggestions on where to look next or characteristics with this year and motor that i might need to know of. Looking forward to you guys feedback. Thanks in advance.

 

[bgbass.1]

Re: 71 25hp evinrude idle problem

sounds like your running to lean when you pull choke out it makes a more rich mixture to keep it running.

 

[tashasdaddy]

Re: 71 25hp evinrude idle problem

welcome to iboats, read this http://forums.iboats.com/showthread.php?t=167352

 

[F_R]

Re: 71 25hp evinrude idle problem

There is a little funnel-shaped seal (called a bearing) around the idle needle, way deep in the hole and out of sight. If it is worn out, it will suck air and make the idle mixture hard or impossible to adjust.

 

[woodducker]

Re: 71 25hp evinrude idle problem

Thanks guys. i finally was able to get an idle after some fine tuning with the lean rich switch. And another problem has arrived. When i give it gas its wants to bog down and eventually give up totally but it will idle as long as it wants. Even in forward gear it bogs down right away. Possible points or firing problem? Or vac. problem?

 

[woodducker]

Re: 71 25hp evinrude idle problem

Also could it be a timing issue?

 

[HighTrim]

Re: 71 25hp evinrude idle problem

That or a link n sync.


Also check to see if the timer base (starboard side, under the edge of the flywheel, linked to the throttle lever) moves smoothly without sticking when you advance the throttle.

Take the airbox cover off & observe whether the throttle plates are parallel.

Also, the timer base should start it's travel before the throttle plates start to open, or else she'll fall flat when you give her the gas.

 

[woodducker]

Re: 71 25hp evinrude idle problem

Thanks ill try that next.

 

[F_R]

Re: 71 25hp evinrude idle problem

ducker, I don't think you got the carburetor clean. Did you remove and inspect the high speed orfice plug? If there is even a hint of any coating or crud in that tiny hole, you will get all the grief you are describing.

 

[woodducker]

Re: 71 25hp evinrude idle problem

Well i took the motor out today and it idled great and i ran it 3/4 throttle and ran good for about ten minutes and then began to what felt like a missfire or missing a tooth off the gears in the foot but the lower unit is in perfect shape. Is this still a possible fuel issue? Things were looking good for a moment.

 

[woodducker]

Re: 71 25hp evinrude idle problem

Also it seemed to only do this in gear and not in neutral. I guess the load on this has something to do with it.

 

[F_R]

Re: 71 25hp evinrude idle problem

Like you ran over a stump every so often? Classic clutch dog and forward gear worn out. Here in FL the customer says "It feels like I ran over a gator every 100 yards."

 

[woodducker]

Re: 71 25hp evinrude idle problem

Yes it does feel like running over a stump. I pulled the guts out of the lower unit and they look fine and the teeth on the shaft seem fine as well is my problem up top or at the bottom you think.