78 Evinrude 140 Won't idle

[gonegatorfishing]

Im running out of idea's on this.<br /><br />It will start and run reliably. It will not idle in neutral for more than about 15 seconds.<br />Idle rpm's are a little higher than the manual at about 900<br />It will start to miss and then dies. Anything over about 1200 rpms and it will run all day.<br /><br />It's a 78 140.<br /><br />I have rebuilt the carbs, replaced plugs, the ingnition modules are new. Compression is an even 125. The jets appear to be original.<br /><br />Is there any way to set the idle timing? The manual states it should have 0 -> 3 deg of adcance at idle but fails to mention how you set this.

 

[Solittle]

Re: 78 Evinrude 140 Won't idle

I am trying to resolve the same issue on my 1988 140's (I have two). I'm not there yet but I think I am close.<br /><br />First off some years ago a mechanic clipped (the thermostats preventing the engines from reaching proper temperature. Clipping is like removing them completely. In addition to other bad things, I am told that this is probably the central problem. Second I did not have the factory recommended plugs. Third my current mechanic also told me to trim out the engines a bit when neutral is needed as this will tilt the carbs just a bit allowing more fuel to bump the idle up a tad.<br /><br />I hope to do the thermostats this weekend and am praying for no frozen bolts. They are a bit of a bitc% to get to due to the exhaust cover. I am doing this myself as the mechanic said that the engines would have to be pulled and that would cost $250.00 in labor. One to the readers on this forum gave me a couple of tips to avoid that. Rayyyyyy - - I hope!

 

[gonegatorfishing]

Re: 78 Evinrude 140 Won't idle

Not sure on the thermostsat issue as it is better when it warms up. <br /><br />I found it was better if I lowered the float level. <br /><br />First time I tried it it was rare that it ran long enough to get it in gear. I lower the float level ( tipped the carb upside down and bent the float arm till it sat level.

 

[gonegatorfishing]

Re: 78 Evinrude 140 Won't idle

It is getting to atleast 100deg. When used for a while the temp does climb up a bit and water out the teltale is to hot to hold your hand under for very long.

 

[FreeBeeTony]

Re: 78 Evinrude 140 Won't idle

I believe normal temp is ~140 deg.....

 

[IndySpecialty]

Re: 78 Evinrude 140 Won't idle

Gonegatorfishing: I think I can help you but first I need you to do a few things, before we get into the carb thing alittle deeper. can you tell me if it acts the same or different with the motor cover on as it does with it off, if you have not tried this please do and let me know. then I will give you a few carb tips & how to set the timing even though thats not your problem.

 

[gonegatorfishing]

Re: 78 Evinrude 140 Won't idle

Will find out tomorrow. If removing the cover makes any difference.<br /><br />Model no is 140843c

 

[Flotsam&Jetsam]

Re: 78 Evinrude 140 Won't idle

I has an '80 Johnson that was doing this. The local marina rebuilt the carbs for the prior owner<br />but it didn't help. He "unloaded" it on me, explaining I'd have to live with this minor problem. The problem was annoying at first, but became quite a bother. I suspected a fuel system problem as did the marina mechanics. No one had ever bothered to tell me that fuel pressure wasn't much of an issue so I checked it anyway. I was surprise (the mnarina was shocked) at the low rpm pressure & reluctantly (begrudgingly?) got me a fule pump. I'm certainly no expert in these matters, but it worked for me once. Do you have a fuel pressure guage you can check it with?<br />Steve

 

[gonegatorfishing]

Re: 78 Evinrude 140 Won't idle

I had looked along those lines as well as a hole in the diaphram wis reputed to make them reluctant to idle. The first time I overhauled the carbs I did the fuel pump at the same time.<br /><br />I have no idea what the fuel pressure is unfortunatly I don't have a gauge. Will check that tomorrow as well. I have a funny memory that last time I tried giving the buld a squeze did help.

 

[gonegatorfishing]

Re: 78 Evinrude 140 Won't idle

Ok After a big tinker with it today it will idle when warm ~800 rpm in gear . It appears that the syncornisation was a bit out. <br /><br />It will even start in neutral with no gas on which is a new feature for it. I am not sure I am still getting wot though as it seems to be a fine art to get it to idle properly and still get the throtles to open all the way<br /><br />It made no difference as to weather the top was on or off.<br /><br />I will still occassionly cut when shifting. When it does it snezes and dies.