Evinrude 1981 2 hp compression rate???

[favre04]

Hi! This is my first time on iboat.com! Hope it works
My problem is that my evinrude 2hp 1981 doesnt start anymore. I opened the carb, everything seemed to be ok, needle looks good and doesnt seem to stick so the float is doing its job. I put some gas in the cylinder it "runned" for 10 seconds dying slowly... Now, is the problem the 2 needles for rich/lean gas? Or is it time to check the compression rate? By the way what is a compression rate "acceptable" to get the engine working without changing the rings?

Thanks for all advices

 

[tashasdaddy]

Re: Evinrude 1981 2 hp compression rate???

welcome to iboats. around 100psi +- but what is more important is that they are within 10% of each other. here are the carb adjustments, about 1/2 way down. http://forums.iboats.com/showthread.php?t=167352

 

[JB]

Re: Evinrude 1981 2 hp compression rate???

On that little rope start single I would settle for a compression over about 80psi, favre.

Those engines occasionally get the tank outlet gummed up so they don't feed to the carb. Try taking the valve assembly out of the tank and cleaning it up. Check that it freely flows fuel when you open it up.

You might also have some gum in the carb itself. Squirt some fuel directly into the carb. If it starts your carb needs to be cleaned. Cleaning that little carb is much more than a cosmetic job. There are tiny orifices in the wall of the throat that fuel goes through to get into the mix. Those must be clear.

Good luck, and let us know what you find.

 

[BF]

Re: Evinrude 1981 2 hp compression rate???

Hi & Welcome...

Have you had this motor a while, or is it "new to you"? Do as JB says, check that fuel flows if you disconnect the fuel line from the carb. More than one owner of these has forgotten that they have a fuel shutoff value under the tank... if it's not opened... well no fuel will be flowing.

On my 2 hp, the tank vent will vibrate closed unless you open it all the way up (so until it won't turn anymore). Then it holds itself open ok. If the vent is closed it will cause a fuel supply problem too, but usually takes a bit of running to show itself.

If it's not a closed or clogged fuel valve, then sounds like a dirty / varnished up carb.

Good luck

 

[favre04]

Re: Evinrude 1981 2 hp compression rate???

On that little rope start single I would settle for a compression over about 80psi, favre.

Those engines occasionally get the tank outlet gummed up so they don't feed to the carb. Try taking the valve assembly out of the tank and cleaning it up. Check that it freely flows fuel when you open it up.

You might also have some gum in the carb itself. Squirt some fuel directly into the carb. If it starts your carb needs to be cleaned. Cleaning that little carb is much more than a cosmetic job. There are tiny orifices in the wall of the throat that fuel goes through to get into the mix. Those must be clear.

Good luck, and let us know what you find.

Thanks for the advice!
First my tank and gas hose are correct when I unplugged it from the carb, the gas was flowing. So I removed the carb from the crankcase and no or very little gas seems to flow there.However, when I turned it upside down, gas started to flow from 2 little holes on each side of the choke butterfly. What are these 2 little holes(not the 2 holes for the screws, but these just above)?
I'm not sure if gas is getting out of the carb to the engine. How can I check?

Last night I removed the float and put it in gas and it floats. The needle seems to work great , it gets in easily.
Could it be a good idea to blow in the tank to see if gas get to the engine?

 

[chimZuk]

Re: Evinrude 1981 2 hp compression rate???

Hi & Welcome...

Have you had this motor a while, or is it "new to you"? Do as JB says, check that fuel flows if you disconnect the fuel line from the carb. More than one owner of these has forgotten that they have a fuel shutoff value under the tank... if it's not opened... well no fuel will be flowing.

On my 2 hp, the tank vent will vibrate closed unless you open it all the way up (so until it won't turn anymore). Then it holds itself open ok. If the vent is closed it will cause a fuel supply problem too, but usually takes a bit of running to show itself.

If it's not a closed or clogged fuel valve, then sounds like a dirty / varnished up carb.

Good luck

"More than one owner of these..." - count me in! Cleaned the carb once, put everything together tried to start up - no luck, even though fuel was flowing. Cleaned the car second time (found out I forgot to clean one of the channels), put everything back - motor runs for 2 seconds with starting fluid and then stalls. After that...

Wenr to get some frozen yogurt, was reading forums while at it, bam - fuel shutoff valve! I exactly recalled that I forgot to open it second time! Came back home - engine started no problemo.

For the rest of the info - both quality screws 1 turn out, compression 99 PSI, spark is present. Going to play with fuel mixtures and run some tests on the lake.

 

[aspeck]

Glad you had success, and that is a sweet looking old Evinrude, but this is a 14 year old thread. Please read the rules and start your own thread.