35 HP Evinrude 1984

[G DANE]

Can anybody tell me what compression should be, on this 35 HP, cold motor ?<br /><br />Is is true 25 HP and 35 Hp have same powerhead, except from carbureator and intake plate?<br /><br />Is it same cylinderhead ?<br /><br />Thanks in advance

 

[G DANE]

Re: 35 HP Evinrude 1984

Replying to my own topic.<br />Can anybody help me with compression and the question of the 25 Hp powerhead.<br /><br />Greatings to you all here from denmark.

 

[Fouled Plug]

Re: 35 HP Evinrude 1984

Not sure about the 25/35 difference, but as far as compression readings, I take all of mine when the motor is warm. I've never trusted cold compression readings, unless its a basic step in a motor that won't start at all. I would hope for around 50-75# cold. I've seen a 60# reading jump to 90 or better when the piston rings expand and/or unstick. Just my humble opinion!

 

[G DANE]

Re: 35 HP Evinrude 1984

Thanks Fouled Plug. I just pulled the lower unit as a guy told me he experienced loss of power like me, and discovered a dead eel in the exhaust blocking it !! But my exhaust was clean and dry. I will assembly again and warm op the engine running in a barrel and let you know the readings.

 

[G DANE]

Re: 35 HP Evinrude 1984

Working om the engine i discovered that the stator plate was moving when i pulled the starter rope. I pulled the flywheel, and i can see the magnets have touched the white coil. Can this affect ignition timing ?? The motor acted exactly as the timing was late when it started loosing power at hte last trip og the season. The exhaust sound became very sharp. I was running low speed for about 1/2 hour, and at last it took almost 1/2 throttle to keep it running just beyond iddle rmp. ???

 

[G DANE]

Re: 35 HP Evinrude 1984

I mesured compression today. It was exactly 110 Psi, both on top and bottom cylinder, cold engine without adding oil. Guess it will increase when warm.<br /><br />What else can be wrong, and how can i find the error ??? Spark looks fine, carbureator is cleaned.<br /><br />

 

[Backlash]

Re: 35 HP Evinrude 1984

Hey G Dane,<br />Compression is good. What exactly were the symptoms you described as loss of power? Was the engine missing or did it sound OK but had no power? Any other history of the motor would be helpful. <br />Backlash

 

[G DANE]

Re: 35 HP Evinrude 1984

I rebuilt the engine last year as it was overheated due to impeller. It got a new block, one piston and rings on both. It has ran OK for 18 months. On last tour of the season we sailed slowly home at night. My little boy was steering, suddenly he told me the engine was acting weard. I took over and discovered it took almost half trottle to keep slow speed, just above iddle. It sounded a bit rough, but i think it was caused by ignition advanced and slow rpm.<br /><br />I cant see anything wrong.

 

[Backlash]

Re: 35 HP Evinrude 1984

Hey G Dane,<br />I believe you've dropped a cylinder. To check it out, get water to the motor, start it up and pull one plug wire at a time. If it runs worse, that cylinder is making power, if no difference, that would indicate a problem cylinder. Once you've identified the problem cylinder, you can determine if it is spark related (my guess) or fuel delivery related. If you need specifics on further trouble shooting procedures, let us know. Shouldn't be too big a problem. <br />Backlash

 

[G DANE]

Re: 35 HP Evinrude 1984

Thanks I will try that. This model has only one carbureator, does´nt it mean ignition is the only possibility.

 

[Backlash]

Re: 35 HP Evinrude 1984

Ignition is the most likely possibility. Check the spark.<br />Backlash

 

[Rex]

Re: 35 HP Evinrude 1984

THE EASY WAY TO GO IS TO CHANGE OUT<br />THE POINTS AND THE CONDENSER.<br />CHANGE PLUGS.<br />IF THAT DOE'S NOT DO IT THEN<br />CHANGE PLUG WIRES.<br />SET CARB AT 1.5 TURNS.<br />THEN LET SEE WHAT THE ENGINE DOE'S.<br />REXA1925

 

[Rex]

Re: 35 HP Evinrude 1984

SORRY.<br />PLEASE LET ME KNOW.<br />REXA1925@IWON.COM

 

[G DANE]

Re: 35 HP Evinrude 1984

This model has CDI, not breakers and condensators, but i will try to start is up and see.<br /><br />I took compression with trottle in iddle, does it affect the mesuring ?<br /><br />Thanks for advise