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2 hp help again

T

Thinman

Member
Haven't got my "barn find" 2 hp engine running yet. It's a '74 Evinrude. Has spark, new pts, condensor, and plug. Overhauled carb, (carb bath X3, new float, needle and seat, new manifold gasket). Have used suggested carb initial settings of 3/4 turns open for high speed. 1 1/2 turns for slow speed. Does fire up, but will not run consistently. Goes for maybe 30 secs and dies. Will not rev up at all with one exception. When I give up. Turn off the fuel line. Run the gas in the carb dry, well then it will rev up all the way. Of course then it dies.

I'm suspecting a fuel problem. That's why I changed the float, needle and seat. Then thought the gas cap vent wasn't venting. Does same with the gas cap off.
Getting embarrassing. Any words of wisdom?
 
It is running out of fuel = running leaner therefor it speeds up.-----------This means that you must adjust the high speed needle on the motor running on a boat and once that is properly set you slow the motor down and adjust the low speed needle for best idle.-----------Initial " book " settings are just that , they allow the motor to start and keep running.-------These initial setting are NOT the final settings.
 
Thanks. I'm with you on the "running leaner, speeds up -------needs to be leaner. Don't get me wrong. I appreciate your input. But, I've tried leaning the high speed jet. No matter, I can't keep it running. Let alone adjusted properly. I realize the initial book settings are initial, but they don't allow it to keep running. Throttling it up does nothing.

I am doing it in a barrel without a prop and not on a boat. That should make a difference??
 
The one that is part of the petcock? Yes, I have checked that out. Initially it was totally obstructed. Had to destroy it to get fuel to flow. Have an in-line one on order now. Also replaced the fuel line, sandblasted the inside of tank, and removed all the sand. It's definitely getting clean fuel now.

I'm now wondering if the throttle spark advancement mechanism is somehow involved. ??
 
guyjg said:
NO....from the 3/4 initial setting.
Click to expand...

OK, tried again. Did the 1/8 turn steps open from 3/4. No difference. Will say it "ran" the whole time. I put ran in quotes because at full throttle it kept going at an uncertain idle pace. I kept doing the 1/8 open increments with no change at all. I quit at 5 full turns.

Wish I had a spare carb to slap on it. Almost certain the carb is some how the problem. Still does the exciting rev up when I turn off the fuel. I've removed the carb again. Will keep you posted. Thx for the help.
 
kimcrwbr1 said:
2hp motors have a real sensitive low adjustment set the high knob out 3/4 turn and the low out 1 1/2 turns pre adjust. in a barrel get it to idle nice and smooth and slow turn the slow knob lean real slow 1/16 turn at a time and wait 20 seconds. If you get a nice idle then take it out and adjust WOT high needle for the best performance and then go back and dial in the slow knob. Have you replaced the head gasket? It may be worth it to get a gasket set and check the cylinder walls for scoring and check the rings. With the side cover off take a screwdriver and press on the rings, they should still be springy if not you need new rings. It`s a 40 year old motor be careful removing bolts and they are real simple look at the reeds close and crankcase seals and the head gasket is probably shot it dont matter about fuel or spark if it has low compression. The high speed needle has very little to do with idle you only adjust it 3/4 pre and then in the water at full throttle adjust it for best performance.
Click to expand...

I've had the side cover off. Will do that again and check rings. Haven't had the head off. Seems to have good compression. It does do the nice full rev up once it's fuel starved. So I haven't ventured there yet. Would it fully rev with the fuel shut off, if there was a compression/ring/headgasket problem?

It's a small motor and easy to work on so I'll try anything.
 
When you rebuilt the carb did you replace/inspect the gasket ( it's more like a fat "O" ring about 3/16" thick) that seals the the bowl from the high speed jet, #21 as shown in the carb exploded view on this site. If that leaks, or is missing, constant flooding will be the result.
 
RGP said:
When you rebuilt the carb did you replace/inspect the gasket ( it's more like a fat "O" ring about 3/16" thick) that seals the the bowl from the high speed jet, #21 as shown in the carb exploded view on this site. If that leaks, or is missing, constant flooding will be the result.
Click to expand...

Yes, I did replace that seal.

I looked at the float level and it first appeared perfectly level. The more I looked it appeared slightly lower than level. I raised it just a tad. It did seem to try running better or maybe my imagination. About to remove again and bend it up more and see if we get better.
 
Thinman said:
Yes, I did replace that seal.

I looked at the float level and it first appeared perfectly level. The more I looked it appeared slightly lower than level. I raised it just a tad. It did seem to try running better or maybe my imagination. About to remove again and bend it up more and see if we get better.
Click to expand...

Correction. I DIDN'T replace that seal #21. I didn't look at the diagram. Presumed you were referring to the seal at the float needle seat. Wow. I think you may have nailed the problem. Will be on it in the morning, if not tonight.

The diagram points down into the bowl for that seal. Just where does it go? In the bottom of the bowl? Wow. That's got to be it.

Here we go again. I'm getting pretty adept at this disassembly reassembly exercise. Thx RGP.
 
Thinman said:
Yes, I did replace that seal.

I looked at the float level and it first appeared perfectly level. The more I looked it appeared slightly lower than level. I raised it just a tad. It did seem to try running better or maybe my imagination. About to remove again and bend it up more and see if we get better.
Click to expand...

Correction. I DIDN'T replace that seal #21. I didn't look at the diagram. Presumed you were referring to the seal at the float needle seat. Wow. I think you may have nailed the problem. Will be on it in the morning, if not tonight.

The diagram points down into the bowl for that seal. Just where does it go? In the bottom of the bowl? Wow. That's got to be it.

Here we go again. I'm getting pretty adept at this disassembly reassembly exercise. Thx RGP.

OH BOY, OH BOY. The Joy The Joy. It definitely helps to put all the pieces back as they were. I'd completely left ole #21 out of the carb. As soon as I listened to RGP and checked the diagram I knew he was on to it. I'd seen #21 sitting in the area of my disassembled parts after I put the carb back together. Didn't realize it was that part. Thought it was one of the #30s I'd replaced. I did think the highspeed jet looked a little ***** sitting there. That's why.

Do feel like an idiot. But a happy idiot. Thanks all for the help. She runs great now. Just did the barrel run and all the little jet adjustments mean something.

We'd just moved to another house. I'm building cabinets in the garage for all my stuff. It's all in boxes and a nightmare to find anything. This rebuild was a little diversion from the woodwork. Guess I made it much more difficult than necessary. My usual method.

Thanks again for all the contributors. You nailed it RGP.
 
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