40 hp evinrude lots of issuses

[akdiesel]

I have a 40hp 2 stroke 2 cylinder evinrude with some weird things going on. At idle it seems to be running on one cylinder but when the rpms go up it seems to smooth out like both are hitting. It will stall out if its in the water when put in gear but with muffs on its fine just a rough idle. The other problem is in gear or using the lever to raise rpms when it gets to 3,000 rpms the motor takes off out of control (runaway motor). Where do I start? I have 3 things that I think it is water in the one carb, carbs out of sync, and or the one carb is clogged up enough to keep fuel out till its calling for more than idle? Compression is 119 in both cylinders. This is my first boat but I am familiar with car and bike motors so shouldn't be much different? Any help would be great atleast to let me know if I am on the right track here with this thing. Oh not sure on the year but is around late 90's. Thanks

 

[fireman57]

Re: 40 hp evinrude lots of issuses

Usually a model number is a big help. It stalls in the water because you need to set your idle with it in the water because the back pressure is greater than on the muffs. Don't rev it in neutral like that because you will get thermal runaway and it will blow itself to pieces. I would start with cleaning the carbs. Soak them overnight and blow out ALL passages. Best is to just rebuild them. Kits are about 20.00 apiece and available right here. Do a search on here for a link n sync and don't skip any steps. Your compression numbers are fine. You would be money ahead buying an OEM manual for your specific engine. Don't get Seloc or Haynes. Go to kencook dot com and he has them.

 

[akdiesel]

Re: 40 hp evinrude lots of issuses

Ok model number is E40TLEUC cannot find it listed. Got the carbs off just waiting on the rebuild kits.

 

[Will Bark]

Re: 40 hp evinrude lots of issuses

It is a 1997 year model.

 

[akdiesel]

Re: 40 hp evinrude lots of issuses

It is a 1997 year model.

Thank You!

 

[akdiesel]

Re: 40 hp evinrude lots of issuses

Update- I rebuilt the bottom carb, the motor was running a lot better but hard to start. I decided to take it out on the water and try it out. Ran it about 45min out, then backed it down because I wanted to see what idle speed was and it died. Messed with the timing screw and got it to where it was starting but would not stay running unless I had the rpms up. Did a quick jockeying of the controls and got her moving again back to the landing. Coming up to the ramp it died on me again. When I got it home I went through all the wiring found a broken ground bolt, corroded terminals. Took care of that but still didn't seem to be responding just right. When I would make adjustments to the top carb nothing would happen. I could turn the screw all the way in nothing all the way out, nothing. Found the fuel prime valve was cracked and replaced that. Decided after I had gone through everything I could think of I would check the reeds. I wasn't getting the tell tale spitting of fuel or backfiring but it was the only thing I hadn't checked. On the top assembly I had found the bottom reed sticking open just enough to let light through when I would hold it up to the sun. All the other three reeds were shut tight with no light shinning through. I took that reed off and massaged it back and reassembled it and now no light coming through. Put it all back together and it runs like a dream, fires up first try, adjusted the carbs, and now idles smooth.

 

[fireman57]

Re: 40 hp evinrude lots of issuses

Great! It always feels good to solve the problem. thanks for posting your results.