18 hp evinrude COMPRESSION ????

[kaashlock]

Hey guys,
Got my compression tester today. What should the compression be on a 1968 evinrued 18 hp fastwin?
Kenny

 

[tashasdaddy]

Re: 18 hp evinrude COMPRESSION ????

depends on how you test it. what i do, is insert the guage, pull the rope. count the times you pull it, until the guage quits going up, then repeat on the other cylinder the same number of pulls, but watch the guage after each pull, to see if you get the same reading at the same time. you want them to be within 10 % of each other, the closer to 100 psi or more is better.

what are you getting for readings.

 

[kaashlock]

Re: 18 hp evinrude COMPRESSION ????

I think I understand. pull the rope like you are starting the engine until the guage stops going up. Whether it takes 2 pulls or 4 pulls, Is this right? Mine are between 100 and 110 on both cylinders.
Kenny

 

[kaashlock]

18 hp compression

18 hp compression

To start of I don't know how to keep using the same post, sorry.

Let me get this straight. I keep pulling th rope, like I am trying to start the engine, until the pressure stops going up. Doesn't matter if it is 2 pulls or 4 just keep going until it stops, correct?
I am getting right at 115 on both cylinders on the third pull. So I am good to go?
Kenny

 

[tashasdaddy]

Re: 18 hp compression

Re: 18 hp compression

you are fantastic. you clik on the little box below far right with the paper and pen.

 

[JB]

Re: 18 hp compression

Re: 18 hp compression

No. Not 2 pulls or 4 pulls. 5 pulls and on every cylinder.

 

[James R]

Re: 18 hp evinrude COMPRESSION ????

I have a "72 model with almost no hours on it. It is like new. Shows 125 each cylinder. I dont have a boat for it or I would use it. These Fastwins are beautiful.

 

[1946Zephyr]

Re: 18 hp evinrude COMPRESSION ????

Those 18's will last till the world ends. Great motors and very reliable. As long as you take care of it, it'll last you forever.

 

[kaashlock]

Re: 18 hp evinrude COMPRESSION ????

On 5 pulls I am getting about 122 or 123 on both cylinders. I guess I am good to go to order my fule pump kit and all the other goodies, huh?
Kenny

 

[tashasdaddy]

Re: 18 hp evinrude COMPRESSION ????

i would say so. then when it is running, decarb it.
enema for the motor. Decarb, take a can of seafoam put 3/4 of it in the gas tank, with only 1 gallon of premixed gas. put the rest in a spray bottle. start the engine, and let it come up to temperature. then remove plugs, and them some real good shot of seafoam into the cylinders, replace plugs, let sit 15 minutes. restart, and spray the rest of the seafoam into the carbs, so the the motor almost stalls, wait and repeat until the seafoam is gone.then take for a wide open spin. then put in new plugs, ad premixed gas to the tank, and take it for a wide open throttle spin. it is going to smoke like a house on fire, during this process.