'75 85 HP Evinrude...couple of questions

Besegen

Seaman
Joined
Jan 28, 2013
Messages
57
I finally managed to find a few spring-like days in these weird Christmas-like spring months to get the fuel/starting issue solved I asked about a couple of weeks ago. Turned out to be a combination of a stuck needle valve and the fuel line sucking air from somewhere. Carb cleaning and replaced all the fuel lines fixed it.

I'm kind of lost now on getting my idle right since I replaced the control cables. My understanding was to set the linkage so that the idle stop screw was against the stop with the cable disconnected, shift in neutral, and warm-up lever all the way back away from start position, then adjust the trunion to meet the linkage. Is this the correct method?

This isn't working though, it doesn't seem to give me near enough throttle to start. The motor wants to start but immediately sputters out when I quit cranking. I adjusted the the linkage with the screw about 3/8" from the stop and the motor starts fine and continues to run as long as the warm-up lever is forward, but even after a ten minute warm-up it wants to sputter and die immediately if I push the lever back much at all. I managed to keep it going once long enough to shift to forward and it again died instantly. It seems to be idling way too slow. This is on muffs too so I know it will be worse in the water. Point is..something is way off. It doesn't help that I can't read my RPM's...the tach isn't working. Its always showing between 1,000 and 1,200 RPMs which I gather from other recent posts means my rectifier is likely bad. I plan to run the mentioned tests tomorrow after my battery gets a full charge tonight and deal with what I find there. In the meantime...I'd like to figure this idle speed thing out. I presume with the old cables never having been installed properly and slipping like they were, and as torn up as they were (fell apart when I took them out) the previous owner may have fiddled the stop screws and everything else out of whack getting it where it seemed right in that condition. Is there a proper method to get it set back right without a ton of trial and error? All I have at the moment is a Seloc manual, and though its helped me to this point with everything else it isn't with this issue.

Also...is there anywhere I can order the nylon trunion retainer caps for the cables? One of them vanished on me when I put the new cables on. I'm not sure it was there to begin with. At the moment I have the trunion wrapped in electrical tape to snug it into the receptacle but it still flexes around more than it probably should. I know its probably something most people would walk to a boat parts guy and get one laying around but I live in a boat parts desert here. Thanks for any help.
 

Bosunsmate

Admiral
Joined
Apr 7, 2012
Messages
6,135
Re: '75 85 HP Evinrude...couple of questions

Did it go ok before you replaced cables?
Could the carbs of gummed up in your off season?
Old cables often dont let the timing go back to the stop lever so by replacing the cables with new ones you may have to advance the idle stop a few turns to where it was actually stopping on the old cables.
Mine is about 8mm off the stop, but i cant adjust it as my cables are worn but if i got new cables it would sit back on the stop but be to far atdc to idle
 

Bosunsmate

Admiral
Joined
Apr 7, 2012
Messages
6,135
Re: '75 85 HP Evinrude...couple of questions

Check compression too.
The easiest way i do it is in a barrel, just advance the idle stop until you get to where it will idle fine when warm. Then adjust the throttle cam on the roller so it opens the carbs slightly when the start lever is fully forward, theres normally a mark there on the throttle cam but i havent being near an 85 hp for a while.
post a photo of the linkages if you want
Check the butterflys are flat at WOT position too
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: '75 85 HP Evinrude...couple of questions

Are you sure it's a fuel issue? Have you checked to see if the engine has spark on all 4 plugwires when the engine is running? The factory parts diagram is available at this website: epc.brp.com If you open up the parts list, but instead go to the tab headed "OB Parts and Accessories" for the 1975 model year. It has a section called "remote control" and inside that tab is a category called "control cable repair parts" You will probably find the retainer cap part number you are looking for. If the part is an engine-mounted part, tab back up to the Johnson or Evinrude tab, then to 1975 85 hp. The engine-mounted cable connections are found on the "intake manifold" parts list diagram.
 

Besegen

Seaman
Joined
Jan 28, 2013
Messages
57
Re: '75 85 HP Evinrude...couple of questions

Bosunsmate, the boat is new to me this winter but yes it ran great until the cables fell apart on me last trip out. I put the new ones on and next time I took it out to try to iron out the throttle adjustment I had a buddy pumping the ball for me and I caught him two hand mashing the crap out of it and the boat wouldn't start. First it was flooding like crazy right away, then after it set awhile I couldn't get it to stay primed. Found a stuck needle valve and also the line sucking air, replaced it all. Not sure if he caused those problems or not doing that, but I'm assuming so. Anyway, should be back to where it was before except getting this throttle/idle adjustment down. Thanks for the advice, I'll follow it. I wanted to check compression too anyway now that I can at least get it started and warmed.
 

Besegen

Seaman
Joined
Jan 28, 2013
Messages
57
Re: '75 85 HP Evinrude...couple of questions

Are you sure it's a fuel issue? Have you checked to see if the engine has spark on all 4 plugwires when the engine is running? The factory parts diagram is available at this website: epc.brp.com If you open up the parts list, but instead go to the tab headed "OB Parts and Accessories" for the 1975 model year. It has a section called "remote control" and inside that tab is a category called "control cable repair parts" You will probably find the retainer cap part number you are looking for. If the part is an engine-mounted part, tab back up to the Johnson or Evinrude tab, then to 1975 85 hp. The engine-mounted cable connections are found on the "intake manifold" parts list diagram.

Yes, last weekend trying to figure this out I was already sure it was all fuel issue, but put on new plugs and checked spark anyway.
Thanks for the parts reference. I'll go look it up.
 
Top