I have a 1974 15hp Evinrude that has developed a starting issue. For the first startup of the day, it takes upwards of 20 mins of pulling to get it going. Generally I finally get it started with no choke, just pulling constantly until I get it to sputter and finally to turn over. After I get it going once, it’s back to its normal self and starts on the first pull every time for the rest of the day. No issues with power or anything, runs very smooth at high or low rpms. I thought it was a fuel line issue, and replaced my primer bulb to no effect. Wondering if it’s a choke issue, seems like fuel delivery is the problem until the motor starts sucking on its own. Any ideas? Hesitant to rip open a carb or fuel pump if I don’t have to.
Boats & Motors
Evinrude 15hp starting problem
So I got to the cabin and finally had a chance to work on it. I was a bit disappointed to see that the choke switch was installed correctly, meaning that wasn’t going to be my easy fix. I ended up taking the air box off to verify that the choke was operating properly in the carb, and everything looked good. When I put the air box back on, I noticed it had instructions to press the air box tight to the carb before torquing the screws down, so I did that. Also pulled the fuel pump off to check the screen and that all looked good. Put it back together and got it started in a water tank on the tenth pull. Took it to the lake the next day and it started on second pull, and ran great all day. Not sure what the actual fix was but it’s back to its old self for now! We’ll see how it goes when I’m back up in a few weeks.
Any update Edward - I'm interested!
I bet that is it Edward! Also, the choke knob fits into a stainless retaining clip - it shouldn’t fall out.
It’s super easy to put it in upside down, you have to pay really close attention to it.
Should also mention that you should try starting it with maximum throttle...
A couple of things...
I have a 15 HP Johnson on my duck skiff and had similar issues.
I found something really interesting when I took the choke assembly apart. Whoever owned it before me installed the choke knob upside down. Basically, all I had to do was rotate the choke knob 180 degrees. The choke knob has a slot in the middle of it, and it is position sensitive.
Take the air box off so that you can see the throat of the carb, and then engage the choke, if you don't see the throttle assy. move you've found your problem.
Believe it or not, I think this is likely the case with a motor that old - the carb has likely been apart a dozen times.
The reason that I think the choke is likely the issue, is that once you get it going, it starts fine for the rest of the day. If you had fouled plugs or a fuel delivery issue, the starting issue would be consistent whether the motor was warm or cold.
Given that it is a cold starting issue, the problem is likely with your choke.