help please with old evinrude outboard 25 hp?>

jjl

Recruit
Joined
Jun 10, 2003
Messages
3
Comment/Question:<br />I have have an Evinrude outboard. THe model number is 25402M and the serial<br />number is E0003793. What year and horsepower? I am having problems and<br />wondered if I can still get parts? Should I purchase a manual/diagram<br />before working ?<br /><br />THe problem is a loud jerking bump at any RPM that makes you think you hit a<br />summerged log. If you put your hand on the top of the outboard it actually jerks and vibrates when you here this sound. I feel no slack in the prop or axile on the foot?<br /><br />Also motor starts choking after about 10 minutes after running fine.? dies and hard to start back then dies again when going in gear?<br /><br />This second problem may be related to the first<br />or so it seems.<br /><br />I would guess the first problem to be more on the drive train not the combustible engine. and the second to be an engine problem but perhaps under undue stress??<br /><br />My gmvksbg@vicksburg.com <br /><br />Help me in Vicksburg.<br /><br />Thanks,
 

Bear

Lieutenant Commander
Joined
Mar 1, 2001
Messages
1,627
Re: help please with old evinrude outboard 25 hp?>

25402 Evinrude 1974 25 HP
 

mercury1

Cadet
Joined
May 31, 2003
Messages
25
Re: help please with old evinrude outboard 25 hp?>

The jerking that feels like you are hitting something is your clutch dog slipping away from your forward gear. Normally there is a reason this is condition shows up, water in the gearcase or old burnt oil without proper viscosity. You will need to replace the forward gear, clutch dog, detent balls/spring, internal bearings and all the seals in the case to get it working properly. I service a handfull of outboards per year with this exact same problem<br /><br />The second problem with the "choking" sounds like a fuel tank vent possibly or some restriction in your fuel system. Starving it of fuel?<br /><br />First thing I would do before making any move on this old of a motor would be to run a compression check, if your engine is weak, there is no sence in fixing the gearcase.<br /><br />Best of luck
 

jjl

Recruit
Joined
Jun 10, 2003
Messages
3
Re: help please with old evinrude outboard 25 hp?>

How can I found out the compression that it should read on this motor?
 
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