Stumped with 18hp Evinrude

[zshuff]

Hey guys, I've got an (approx) 1957 18hp Evinrude I just picked up. It is a pull start and electric start. All the electrical has been newly replaced and motor has good compression. I have inspected the electrical and it's all working and I have good spark. However the carb was a mess when I picked it up and I new it would have to be rebuilt. I picked up a carb kit and installed new float and gaskets. Sprayed the carb out thoroughly and re-assembled. When I got it back together the motor would not stay running. It would fire up and run for a few minutes and then die. I have tried adjusting the low speed knob and its not doing much. The needle feels loose even though I've got the outside brass fixture tightened all the way down. The high speed needle seems firm so I'm pretty sure my problem lies with the low speed mixture. I tore down the carb again and will soak overnight in a mixture of sea foam and carb cleaner just to be certain my carbon deposits are gone. Does anyone have any other suggestions as to what I may be overlooking here? I also would like to know how I can firm up that low speed needle to keep it in place? Thanks for the help!

 

[nwcove]

Re: Stumped with 18hp Evinrude

did you pull the welch plug on top of the carb, run a small strand of wire through all the passages?? how many packing washers did you use on each needle? still running pressure tank or converted to pump?

 

[zshuff]

Re: Stumped with 18hp Evinrude

It runs off a single line tank and I assume to fuel pump is good because it was replaced with all the electrical which was about a year ago. Not exactly sure what the welch plug is but I pulled everything off the carb that I could to spray it out. I did not run wire through so I guess that's something I could try. Where would I find wire that small to run through it? Both carb needles have a brass nut that goes over the needle to screw in and keep it in place. The high speed one seems to keep the needle firm while the low speed needles feels very lose once its backed out from the carb at all.

 

[nwcove]

Re: Stumped with 18hp Evinrude

very important to remove ,clean under,and replace the welch plug. you can use a wire from a twist tie or similiar to clean the passages, and as mentioned, how many...if any packing washers from the kit did you use on each needle? and you did make sure that none of the old packing "s" were left behind? have you tried pumping the primer bulb when it start to die?

 

[zshuff]

Re: Stumped with 18hp Evinrude

Ok it seems that I did not remove the welch plug. Ill try that and see what else I can clean. Should a new welch plug have come with my carb kit?

 

[nwcove]

Re: Stumped with 18hp Evinrude

yes, new plug should have came in the kit. what about the packing washer question. ( loose low speed needle).

 

[zshuff]

Re: Stumped with 18hp Evinrude

I don't have any washers around the low speed needle or my high speed needle. I thought the brass bolts were to keep those needles in place? Ill check my kit and see if I have some washers.

 

[zshuff]

Re: Stumped with 18hp Evinrude

Ok I removed the welch plug. The jets didnt look clogged but who knows at least now I know they will get clean. I will continue to let everything soak in carb cleaner.

 

[lindy46]

Re: Stumped with 18hp Evinrude

You HAVE to install packing washers around the needles to keep gas from leaking out and to tighten the needle. The packing nut tightens up against the packing and seals the needle so it doesn't leak or turn too loosely.

 

[nwcove]

Re: Stumped with 18hp Evinrude

I don't have any washers around the low speed needle or my high speed needle. I thought the brass bolts were to keep those needles in place? Ill check my kit and see if I have some washers.

heres what the packing washers look like, i prefer to use three on each needle. make sure to carefully remove ALL the old packing ! be sure to snug down the packing nuts after a few runs as they tend to loosen up a bit.

 

[zshuff]

Re: Stumped with 18hp Evinrude

Ok thanks for the info. Ill make sure I do that. Do I screw in the needle then put the washers on or do I need to slide the washers over front of the needle and then screw in?

 

[twocyclemania]

Re: Stumped with 18hp Evinrude

It doesn't matter. Make sure to use two washers for both the high and low speed. I usually put them on the needle, thread it in part way and than tighten the nut down on the washers until turning the needle is a bit stiff but loose enough to feel when the needle seats. Adjust your needle setting and than tighten the nuts enough so you can still turn the needle but it's not loose. Without these packing/washers you're going nowhere. Make sure the coils are in good condition. You can have the motor run for a bit but under load it will crap out if you have bad coils. Check the coils and make sure they're not the originals. The originals are probably a semi clear pink-like plastic. If you have them they're definitely shot. Don't even think about them being any good. An 18 OMC is a fantastic motor.

 

[twocyclemania]

Re: Stumped with 18hp Evinrude

You may want to take the advice of nwcove and use 3 washers. The two I recommended was a minimum but 3 may be even better. You want a nice tight seal.

 

[zshuff]

Re: Stumped with 18hp Evinrude

Ok thanks guys. I've already checked the coils and they were replaced along with the entire electrical system so I think we're good there. I have the carb parts soaking overnight and will re-assemble and add the carb needle washers in the morning. Also, I had a thought that perhaps I may have some metal flecks in my gas. The gas tank that came with it was an old 3 gallon metal tank. I've got a plastic 6 gallon I may switch with so I can eliminate the possibility of that gas can effecting my situation.

 

[zshuff]

Re: Stumped with 18hp Evinrude

Ok so I re-assembled carb and my low speed needle still will not sit all the way. There is a silver threaded peice that is in the carb needle slot that will actually come out with the needle if I pull it. Is this supposed to happen? I placed the washers on the needle before the brass tightening nut but when I go to turn the needle all the way in it will firm up but never stop turning. I feel like the silver threaded peice is just turning with the needle allowing the needle to just spin but never tighten down. The bottom needle (high speed) sits just fine and then I back it out a turn and a half and tighten the brass nut and I'm good to go. I've still not got it to crank. I checked the electrical one more time and ill got real nice blue spark so it's got to be this carb.

 

[kfa4303]

Re: Stumped with 18hp Evinrude

HI z. Here are some great links that can walk you through a tune up and carb rebuild from top to bottom.

Maintaining Johnson E & FD Serie (great overall tune up link)
5.5 HP Evinrude Johnson 1954-1954 Carburetor Tune-Up Procedure (great carb rebuild link. It's for a slightly different model, but all of the steps are the same for your carb)
1957 Johnson FDE-11 18 hp Outboard Motor Parts (parts catalog for the Johnson model of the same year. All of the major part numbers should be the same for your motor.)

 

[zshuff]

Re: Stumped with 18hp Evinrude

Thanks but I have already rebuilt the carb. My problem is that my low speed needle won't seat so I can never find my optimum setting to get the motor to crank.

 

[twocyclemania]

Re: Stumped with 18hp Evinrude

You have two things threading themselves into the carburetor body. The needle and the (hollow where the needle slides through) nut that tightens against the fiber washers. I'm not sure I'm following you but from what I can gather is one or both of these threaded items or the carburetor body has stripped threads. These threads are fairly fine (especially the needle and the aluminum carburetor body) and in my experience I've a couple carburetor bodies / needles that the thread was worn (not crossed or messed up, just worn) and so they would just keep turning. I'm suspecting this is your problem.

 

[zshuff]

Re: Stumped with 18hp Evinrude

Well... I don't know. The threads don't look worn but I could be wrong. There's a hollow silver peice inside the carb that the needle threads into. There's also the brass hollow peice that screws into the front of the carb over the needle. That silver peice is what my problem is I think. It has become detached from the carb and will actually come out. Once the needle threads all the way into that peice it just spins along with the needle not allowing the needle to seat properly. I may just have to take it to my mechanic.

 

[nwcove]

Re: Stumped with 18hp Evinrude

http://forums.iboats.com/johnson-evinrude-outboards/1957-18hp-johnson-seahorse-468398.html