Evinrude 150, coughing & hard start

[blue.monkey]

Hello,<br />I have an evinrude 150, year 1989, ser # E150TXCEM. I have a problem with intermittant very hard starting and coughing, bucking and power loss at the same time. I went to the dock today to look at it and replaced plug wires because they looked damaged. I also did a compression test, it was ok. It started great, I exersiced the throttle and it ramped up nicely. I let it run for about 15 minutes, and it instantly started to run poor, ( I periodically ran the throttle plates up to prevent it from loading up). when it is running poor, it bogs down and stalls. And when i left it moments ago it would not restart at all. Although the VRO system is installed, I run 50:1 in the tank because the VRO does not appear to work. When i was testing it today I crimped the oil injection hose to eliminate the possibility of loading up on to much oil. <br />Any advice would be greatly appreciated. <br />Thanks,<br />Kevin

 

[JB]

Re: Evinrude 150, coughing & hard start

Hi, Blue monkey.<br /><br />Seems that the engine may have to warm up before it misbehaves. My guess is that it is dropping one to three cylinders.<br /><br />Could be a fuel starvation problem or could be a hot failure in your ignition system.<br /><br />Let her run until she starts misbehaving. Disable each cylinder and observe the effect on rpm. If there is no change, that cylinder is dead.<br /><br />Side by side dead cylinders indicate a carb problem with the one that feeds those two. One side dead indicates a bad powerpack.<br /><br />If all six are running, but very poorly, try squirting a bit of fuel into the carb throats. If it picks up, go to your fuel/oil pump. Disconnect the oil input hose (if it is still there) and securely plug that inlet. It may be pumping air into the carbs.<br /><br />Let us know what you have found and we can proceed from there.

 

[blue.monkey]

Re: Evinrude 150, coughing & hard start

Thanks for the reply JB.<br />What I forgot to put in the previous post was that the problem first materialized while trying a dead cold start. Now It does it warm and cold. <br />Also, I forgot to put in the post that when I ramp up the throttle plates the idle never lands back in the same place, sometimes up to sometimes 300 rpm off. <br />I went down to study it again this afternoon. Brought with me a fresh mix of gas/oil for it to drink from a 5 gal can to rule out bad fuel or water. The fuel didn't make a difference. <br />I did notice when it coughs I see a puff of smoke or something coming out of the carbs base gasket area. And today when it would not restart I could start it easily by opening the throttle plates about 20%. Maybe by opening throttle plates its not going to leak by the base gaskets? <br />Could that be why even though It is very difficult starting it runs well on the high end?<br />One more thing, I noticed that when it coughs at idle, there is a noticable knocking noise from the VRO/Fuel pump, (like plastic on plastic), is this normal ?<br />Thanks for any help<br />Kevin

 

[blue.monkey]

Re: Evinrude 150, coughing & hard start

I replaced the carb base gaskets and it seemed to <br />do the trick.