'76 55hp evinrude no idle but runs ok? Help, please.

[santuitman]

Hello All<br />I have finally got back in the water after a few years and some help here! I recently rebuilt the carbs on this motor as there was gunk in them. I went for a short test run a couple weeks ago and it ran well but the idle wasn't too smooth. Yesterday I put in new plugs and turned the idle up a bit( while not running) hoping that when I got to the lake with the family it would be ok. Once in the water the boat would not idle. I could not use reverse as the rpm's would drop too low to shift. I could get going in forward by quickly dropping the high idle lever then slamming into gear before it died. Once in gear the motor ran well at any rpm over ~1200. As I wanted to enjoy the day I just didn't try to idle. At the end of the day it still wouldn't idle .(fun getting to the trailer!) <br />Any ideas what I may have done wrong or what else to check. I thought I set the idle mix screws correctly when I put on the carbs and when I set them it did seem to idle ok then. (on muffs)<br />Thanks in Advance for any ideas!!<br /><br />Brian Kelley<br />BTW After this season I think I'm going to have a real mechanic go over the motor so I'm hoping to just get the rest of the season out of it!(anyone recommend a mechanic on Cape Cod? )<br /><br />Thanks again<br />Brian

 

[hooksetter62]

Re: '76 55hp evinrude no idle but runs ok? Help, please.

try decarboning the engine, use seafoam--use 1 gal gas 3oz oil and seafoam as directed on the can. use a hose to stick in the gal can or jug then to the engine, run it thru until it runs out,then let sit for approx 30 min. then hook up reg fuel line system and then restart then let it run to clear it out. may have to do again. remember the idle will change when you put in in the water as the back pressure from the exhaust will slow it down. hope this helps, helped mine for the same problem. good luck ps, rpms will have to be higher when on muffs then when in the water

 

[santuitman]

Re: '76 55hp evinrude no idle but runs ok? Help, please.

You run a whole gallon of gas through? that must take a while. I've seen some of the other posts about seafoam, it sounds like it smokes alot,it that true? I looked at their website and it's a bit confusing. Hopefully the can makes more sense.<br /><br /><br />Thanks<br />Brian

 

[CATransplant]

Re: '76 55hp evinrude no idle but runs ok? Help, please.

Hmm...was it idling properly before you rebuilt the carbs? Sounds to me like you need to go back through them again. The low-speed circuit could still be clogged.<br /><br />You said it runs fine at mid to high rpms, so it's very likely that there's a problem in the low-speed passages.<br /><br />A soak in carb cleaner and a complete blow-out of all passages with compressed air should clean things out.

 

[santuitman]

Re: '76 55hp evinrude no idle but runs ok? Help, please.

Before the rebuild it idled ok but a little rough. After rebuilt it still idled ok but a little rough. It idled ~5-700rpms on the muffs while I set the idle mix screws then on the trial run it wouldn't idle. I assumed that it was 'cause I set the idle out of the water and that's why I hoped just turning it up would be ok. I should have turned it up in the water but I was in a hurry. I also should have brought tools to the lake but was hoping that it would idle good enough in the water. Maybe I should decarbonize and then try to reset idle mix and idle speed.<br />As you guys know it's hard to spend those few hours you have on the weekend working on the boat when you should be useing the boat! I tried pretty hard to clean out the carbs but admit I didn't do a stellar job. It did idle well enough for me to set the carbs so that's why i'm a little mystified.

 

[Goodoleboy]

Re: '76 55hp evinrude no idle but runs ok? Help, please.

Your Idel is set much to low. On the muffs it should idel 900 to 1000. In the water it should come back to 650 to 750. The lower the better. Just so it keeps running while in gear and not restrained.<br /><br />Back pressure is why the rpm,s drop in the water.<br /><br />Good luck.

 

[santuitman]

Re: '76 55hp evinrude no idle but runs ok? Help, please.

I got a can of seafoam at lunch but now I am confused as to how to use. I'm guessing I got the additive by mistake and it looks like there is a spray that is described in the FAQ for Decarbing. What were you using Hooksetter... or can anyone else give me an idea about >I guess< mixing it with the fuel.

 

[hooksetter62]

Re: '76 55hp evinrude no idle but runs ok? Help, please.

use the can of seafoam fluid not the spray. use i gal of gas-3oz of oil and approx 3-4 oz of seafoam. run thru motor,yes it will smoke but this is how it cleans,it might idle for awhile or so but you cant rush the cleaning process. good luck, let us know how this worked for you.

 

[santuitman]

Re: '76 55hp evinrude no idle but runs ok? Help, please.

Ok I get it now... I think I've got ~ a gallon left in the tank now. I'll double check that and then add the 3-4oz of seafoam. Hopefully I'll be able to do it this weekend. It sounds like I can just set it up on the muffs and let it run for a bit.<br />Thanks everyone...

 

[hooksetter62]

Re: '76 55hp evinrude no idle but runs ok? Help, please.

your very welcome santuitman,hope this helps your problem,remember to reset your idle when on muffs,approx 900-1000 rpms on the muffs. let us guys know if we have helped. good boating. better idleing in the back yard than to be stranded out on the lake!

 

[santuitman]

Re: '76 55hp evinrude no idle but runs ok? Help, please.

Originally posted by hooksetter62:<br /> better idleing in the back yard than to be stranded out on the lake!

You got that right! One of the reasons I've been going to the lake is I know someone will help to tow if I get stuck. I hated dropping it in gear when it was revved up a bit. I know that's a horrible thing to do. <br />I have some things to do on Saturday but hopefully Sunday I'll have some time. I will definetly post results when I do the seafoam thing.<br />Thanks to everyone!!! I wouldn't have gotten it in the water at all this year without the help I've found here

 

[santuitman]

Re: '76 55hp evinrude no idle but runs ok? Help, please.

Hello All <br />Between rain and relatives it's been a while before I could run the boat. It is definately better and smoother after I readjusted the carbs and did the seafoam thing but it still won't hold low idle for long. Sometimes 2-3 minutes, sometimes 30 seconds. I think part of the problem is worn linkage as i can wobble some of the bits in directions they're not suppose to go. I'll try to use it some( hopefully this weekend) and just try to enjoy it for the rest of the year then take a hard look at a full rebuilt over the winter.<br />Thanks again to everyone!!!!!