81 Sea-horse 2hp only has low rpm

[pman7]

Thought I'd start here and see if someone can give me some fresh ideas because I'm tapped out. I tried to fix this motor about 3 years ago and quit because it stumped me and a buddy of mine that's actually pretty good with fixing old outboards.

I got this motor from my brother, who is a damn good mechanic. I'm taking the motor back to him now because I'm stumped. I'd like to have a suggestion or two for him to try.

The motor starts fine, idles (not perfect but near it), and seems fine until I try to accelerate. When I try to accelerate, even in a test barrel, the motor bogs down and starts sputtering roughly and sometimes even dies. But it will easily start right back up and do it all over again.

I've done a compression check and it was fine. That was 3 years ago so I don't remember the compression number but it was fine. I've changed the gas line, filter, checked the gas tank, changed the plug (fire seems fine), checked the timing, cleaned the carb several times and put in a new carb kit.

When my brother had the motor it ran fine. He didn't use it a lot and it may have set for a year or so before I got it. But when I tried it, the motor acts like I've described. So one might assume it's something that occurred while the motor set idle. The tank was empty when I received it.

I've got the OMC parts and service manual

There is no fuel pump, I believe it's a gravity feed and like I said the line is now new. My machinist buddy here is speculating reed problems because he's as stumped as I am. But he's only guessing. I imagine my brother can fix it but I'd like to get some suggestions from somebody here that possibly has had an issue like this.

Any suggestions would be appreciated.

 

[Daviet]

Re: 81 Sea-horse 2hp only has low rpm

Will it pick up and run if you squirt some fuel mixture into the carb when it is acting up?. There should be a filter screen on top of the shutoff valve inside of the tank, maybe it is plugged.

 

[pman7]

Re: 81 Sea-horse 2hp only has low rpm

I removed the screen out of frustration. I don't recall squirting into the carb but will try that,

Thanks.

 

[Daviet]

Re: 81 Sea-horse 2hp only has low rpm

If it does pickup by squirting fuel into the carb at least you will know that you have a fuel problem.

 

[pman7]

Re: 81 Sea-horse 2hp only has low rpm

I went over and talked to my buddy here that helped me and he said we did squirt gas into the carb but still couldn't get it to run fast with power.

He said it runs like the high speed jet is clogged but we know for a fact it isn't clogged.

 

[Daviet]

Re: 81 Sea-horse 2hp only has low rpm

Well I would think it has to be electrical then. Compression is good, will not pick up with added fuel, the only thing left is an ign problem. Coil breaking down, points, condenser, or plug wire arking, just some thoughts.

 

[cajuncook1]

Re: 81 Sea-horse 2hp only has low rpm

If you are sure you have good compression and good spark, then fuel delivery is your issue(i know duh...but just follow along for a bit)

You stated that you cleaned your carburetor and put in a kit.(OK) You stated that you cleaned your tank and fuel line and the filter is cleaned as well.(OK).


****Please make sure your vent cap is open to allow good delivery and flow. Make sure the little valve in the cap is not clogged with dirt, oil or grease......Wouldn't be the first time that little bugger cause running problems!!***

Questions:

1. When you clean your carburetor did you pull out the core plug above the slow idle needle and clean that little chamber in there? See item #6 in the diagram supplied in the link below. (There are three tiny little hole in there that make it possible for adjusting the right air and fuel mixture) This primary for slow idle.

http://www.boats.net/parts/search/BRP/JOHNSON/1981/J2RCIB 1981/CARBURETOR/parts.html

2. When you put the carburetor kit in did you make sure the float was even and level with upper carburetor body when it is flipped upside down? Did you make sure the little hair pin clip was properly attached the float arm? See the link below. A float that is properly adjusted will prevent more fuel from being introduced when the fuel bowl is full, by pushing the needle valve up into the seat. (prevents over fueling/flooding of the carb)

http://forums.iboats.com/showthread.php?t=244013



3. Is your high speed carburetor needle in good shape. See in the parts diagram item #23. If it is damage or bent on the tip you may have to replace it. If your high speed needle is set to rich or too lean you will not be able to open up and speed up the motor. You will either have and too rich or lean situation. See the information supplied below to help you with the carburetor low and high speed adjustments.

http://www.boats.net/parts/search/BRP/JOHNSON/1981/J2RCIB 1981/CARBURETOR/parts.html


Here is the link to Joe Reeves carburetor adjustment. Your carburetor has a high speed adjustment(bottom) and a slow speed adjustment (top).

http://forums.iboats.com/showthread.php?t=167352

This one pertains to you and your motor, but I supplied the link above which is found at the top of the Johnson/Evinrude forum labeled as Secret Files.

Quote:
--------------------------------------------------
(Carburetor Adjustments - Two Adjustable N/Vs)
(J. Reeves)

Initial settings are: Bottom high speed = seat gently, then open 1 turn out. Top slow speed = seat gently, then open 1-1/2 turns.

Setting the high and low needle valves properly:

NOTE: For engines that DO NOT have a shift selection, obviously there is no NEUTRAL position. Simply lower the rpms to the lowest setting to obtain the low speed needle va /lve adjustment.

(High Speed) Start engine (it will run pretty rough), shift into forward gear, take up to full throttle. In segments of 1/8 turn, waiting for the engine to respond between turns, start turning in the bottom high speed needle valve. You'll reach a point whereas the engine will either start to die out or spit back (sounds like a mild backfire). At that point, back out the needle valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest setting.

(Low Speed) Slow the engine down to where it just stays running. Shift into neutral. Again in segments of 1/8 turns, start to turn the top needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running. Eventually you'll hit the point where the engine wants to die out or it will spit back. Again, at that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

When you have finished the above adjustments, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.

********************
If after you adjust the carb and your still having a problem then you will have to get a carburetor kit for your motor and clean it well. Hopefully, with Joe Reeves excellent instructions you will be in business!


Good luck sir and hope this helps you out. Had very similar situation with my 2hp Johnson 1972 model. Runs like a champ now.

 

[pman7]

Re: 81 Sea-horse 2hp only has low rpm

That ought to keep me busy for a while. A sincere thanks to both of you.

I think I'm going to try it myself instead of whining to my know it all brother.

 

[Daviet]

Re: 81 Sea-horse 2hp only has low rpm

For something so small and simple, these things can be a pain in the rear at times, can't they.

 

[cajuncook1]

Re: 81 Sea-horse 2hp only has low rpm

Well I would think it has to be electrical then. Compression is good, will not pick up with added fuel, the only thing left is an ign problem. Coil breaking down, points, condenser, or plug wire arking, just some thoughts.

If after you read the supplied information for the carburetor and made adjustment with no change in outcome, then Daviet is right, you need to start investigating the ignition issue. Just because it spark at the end of the spark plug, it does not mean your ignition system is in order.

You need to assess the quality of the spark. Your spark could be weak and the only way to assess the quality of the spark is to use a spark tester. Also assess the point condition and proper gapping!

Look at the supplied link (jbjennings did an awesome job!!)

Here is a link supplied by Iboats in the Johnson/Evinrude Repair section that we are in now. It is a sticky at the top of the page listed as Secret Files. (There is a bunch of really good stuff in there.)

http://forums.iboats.com/showthread.php?t=294072

Remember when you go to adjust and set the new points. Remove the spark plugs from the motor. This will make turning the crank shaft much easier and prevent accidental starting of the motor.

Also when go to gap the points, only one set of points can be set at one time. To set the other, the crank shaft has to turned clockwise (put the flywheel nut on and turn the crank with a wrench or shock wrench) until the point shoes riding along the cam open the opposite set of points (the other set of points are now closed).

(The same principle applied but you only have one set of points and one coil) Make sure you put a little oil on the wicker to prevent the point shoes from wearing out.....That is the only place any oil should be applied in the ignition case.

Good luck and I hope you get her running soon!!

 

[pman7]

Re: 81 Sea-horse 2hp only has low rpm

Just wanted to report back that I got my motor running. It was indeed one side of the reed valve stuck open like my buddy suspected. I have no clue how he suspected it. I didn't even know where to look to check without looking in the service manual.

I took the carb off to look it over again and clean up again and my friend looked down the throat where the carb came off and he could see one side of the reed valve open.

We took off that intake manifold portion and carefully removed the reed valves. There was a tiny (maybe half a millimeter or less), piece of cream colored particulate that was stuck between the open reed and the housing the reed was screwed to. It was wedged close enough to the screw that it was stuck tight while holding the reed maybe 3/16" open.

The reed wasn't bent so we put it back together with some locktite. We first sanded a bit on the manifold sealing surface to true it up flat as you could still see the original manufacturing machining marks on the manifold where the reed is supposed seal. After we were done it was sealing better than it probably was new.

To make a long story short, IT RUNS!!!

Thanks to both of you that helped with encouragement and advice.