1958 evinrude 18hp fast-twin

[G-loomis]

HELLO
I bought this motor a 6 months ago, when I got it the guy ran it, started on 2nd pull ran fine, I bought it brang it home tryed it on a little aluminum boat ran good but not full out then stopped I had no gas left, I brang it home I mixed oil and gas to 50:1 it won't start anymore not even a puff (all it will do is just back fire when I try to start it) I was looking around the carb to see if I could see anything, I looked I seen gas dripping from the carb on the bottom, I pumped the tank (pressurized) and just started to pour out from a hole on the top and on the bottom, I took the carb apart and seen that the cork float was a dark brown and when I put the carb straight the float just sat on an angle, I hope it can be fixed Can you help..
BRAD

 

[wbeaton]

Re: 1958 evinrude 18hp fast-twin

Hi G-loomis,

I bought your 1968 Mercury 3.9 hp. Got it back together and it runs great.

First off, the fuel mix for that motor is 24:1 not 50:1.

Sounds like the float is saturated. Go to your local OMC/BRP dealer and buy a carb kit with a new float. Part number OMC 439071 or at NAPA (Sierra) 18-7222. Since you've got it apart thoroughly clean out all the passages in the carb. Clean and set your points to .020". Maybe get new plugs too (Champion J6C).

Also, the float should be level when turned upside down. Do you know the compression numbers on that motor?

 

[G-loomis]

Re: 1958 evinrude 18hp fast-twin

HI Wbeaton I hope you like that motor, I will go and get a carb kit with a new float, and where is the "points" located and how do I set them.
thanks
BRAD

 

[wbeaton]

Re: 1958 evinrude 18hp fast-twin

The points are located under the flywheel. To get to them you have to remove the cowl and the rope starter. On top of the flywheel there is an inspection plate. Remove the plate. The points are the two small round contacts that the arrow points to in the picture I've attached. Lightly rub the contacts with a small file or emery cloth and clean them with some carburetor cleaner. Then set them using a .020" feeler gauge and a standard slotted screw driver. When you turn the adjusting screw it will change the point setting. The feeler gauge should fit snuggly between the contacts, but a .022" gauge should not.

Also, check out the following website. Read up on the complete tune-up procedure for the 5.5 hp motor. It is a little different than your motor, but the basic info is the same. It would be a good primer for you. Once you get it running. Replace the water pump impeller. I know that motor needs it.

http://www.outboard-boat-motor-repair.com/

 

[wbeaton]

Re: 1958 evinrude 18hp fast-twin

I guess I should have asked this already, but was it pumping water before it died?

 

[G-loomis]

Re: 1958 evinrude 18hp fast-twin

I am pretty shure it was pumping water, when I had it running it had s good spray coming out from the exaust.

 

[G-loomis]

Re: 1958 evinrude 18hp fast-twin

Do I also have to buy a puller kit to get the flywheel off to get to the points.

 

[wbeaton]

Re: 1958 evinrude 18hp fast-twin

You don't need to pull the flywheel unless the coils are cracked and need replacement. I believe the coils were supposed to have been changed in that motor, but I never saw them so you'll have to check yourself. You can set the points through the hole under the inspection plate on the flywheel. In fact, that's what its for.

 

[G-loomis]

Re: 1958 evinrude 18hp fast-twin

I will try to work on it friday, and get the new carb kit.

 

[G-loomis]

Re: 1958 evinrude 18hp fast-twin

Wbeaton does Napa have these replacement carb kits.

 

[wbeaton]

Re: 1958 evinrude 18hp fast-twin

Yeah. They sell the Sierra brand aftermarket kit. The part number with float is 18-7222 or at least that's what the catalog shows. I normally buy the OMC/BRP carb kit because my dealer always has them in stock.

 

[pgdignan]

Re: 1958 evinrude 18hp fast-twin

check the reeds while you have the carb off. It only takes a few minutes and if it turns out to be a reed problem it's still a cheap and easy fix. Far better to check them with the carb off than to put it all back together only to find out it won't run. :redface:

 

[G-loomis]

Re: 1958 evinrude 18hp fast-twin

HI pgdignan where can the "reeds" be located on the carb

 

[G-loomis]

Re: 1958 evinrude 18hp fast-twin

HI Wbeaton I took off that plate and inspected the inside, I looked around hmmm thats weird, some one replaced only one of the coils one is black and one is green, both are good with no cracks that I can see, I took off the carb and looked at the float, it was saturated for sure and not very straight. will pick up a carb kit tomorrow

 

[wbeaton]

Re: 1958 evinrude 18hp fast-twin

Hi Brad,

The miss matched coils are pretty common. Sounds like they've been replaced (at different times), though. If you go to NAPA to get the carb kit, double check that the Sierra carb kit comes with the float and is for your year. I don't know if the newer style 18 hp carb kit will work in your motor.

The alcohol in todays fuel eats the shellac off the old floats and they get saturated and sink in the bowl, which causes the carb to flood. When the float is in place and the carb is held upright the float should hang at an angle. You set the float with the carb upside down. The float should be level (horizontal) with the line of the carb body.

The reed valves are what you see in the hole behind the carb under the air intake. They are little flaps that open and close do to the vacuum inside the motor. They need to be free from debris, wrinkles or other obvious damage and forming a good seal. If they are not working properly you won't get the motor started. Usually sounds like a backfire out the carb. I've never had a motor yet where they have failed, but I'm sure I will eventually.

 

[G-loomis]

Re: 1958 evinrude 18hp fast-twin

well I set the points and put the starter back on, I then checked the compression, on both cylinders it was about 90 on both, I went to Napa and had to order 3 different things I had to order 2 carb kits and a float (hopefully the right one) guy at napa said that it would be till 3:00 when I can pick it up.

 

[pgdignan]

Re: 1958 evinrude 18hp fast-twin

Sorry for the late response G. The reeds are located behind the intake manifold.. If you have the carb off, the plate that the carb attaches to covers the area where the reeds are. I actually had a reed break off on my motor, pretty frustrating, it sounds like it wants to start but just won't catch. One way I've heard that you can check the condition is by holding a business card in front of the carb and pulling the starter. If the card moves out, away from the carb mouth, you've got a reed problem. Luckily the gaskets and reeds are relatively cheap.

 

[G-loomis]

Re: 1958 evinrude 18hp fast-twin

well today I bought a carb kit from napa but did not come with a float so I got to pick one up tomorrow, I took it all apart, I was talking to the napa guy and he said I got to take a 1/8th drill bit and drill really slow to take off a piece on top where the "reeds" are, so I did took off the metal peace and seen that there was no flaps just 4-5 holes I cleaned it up with carb cleaner and put a new one one top of the "reed" valve. I also made a new gasket for the pressurized tank.

I also have another question.
I was talking to a guy at the grocery store and talking about outboards, he said he has one sitting in his basement for the last 15 or so years, and has very low hours on it and wants to get rid of it, he asked me if I wanted to buy it for 150.00 does this sound like a good deal, he said only used a few times and got the carb rebuilt. WHAT DO YOU THINK. HMMMM!!!

 

[wbeaton]

Re: 1958 evinrude 18hp fast-twin

LOL! I have a basement FULL of those "low hour" motors. $150 could be a good deal, though. What is the year, make and hp?

Are you sure you were looking at the reed valves and not the idle ports in the carb? If you had to remove a metal disc from the top of the carb to view them then you didn't look at the reeds. You were looking at the idle ports in the carb. I hope you also lightly taped that new disc (welsh plug) flat to seal it. I also use a little blue silicone along its edges to seal it, but its too late for that now.

I have attached a diagram of the carb intake from a 1957 18 hp. It should be pretty well the same as yours. The reeds are the star shaped piece #4, which sit tight against the leaf plate #5 behind the air intake manifold #16. Unless you removed the intake manifold you couldn't get a very good look at the reeds. However, if you looked in the hole in the intake manifold where the carb connects and saw only the holes in the leaf plate and no reed valves then you have problems. I doubt that is what you saw. I also wouldn't spend much time worrying about it either. If the carb is still off then shine a light in there and see if you the holes in the leaf plate are completely filled and looking ok. They should all look the same.

 

[G-loomis]

Re: 1958 evinrude 18hp fast-twin

the motor is a 1958 18hp evinrude, he bought it off a guy who passed away and been sitting in the basment for 15 years now.

the fuel mixture for the 58 evinrude 24:1 not 50:1