1999 Evinrude 15 hp 4 stroke

[Koosma]

Hello everyone,
I am new to this form and have found some very helpful tips but nothing that gives any help with a problem I am currently experiencing.

I recently bought a 12 foot aluminum with a 1999 Evinrude 15 hp 4 stroke for fresh water exploration up here in Manitoba, Canada. I bought it from a roommate that used it here and there at his lake and thinks he only put about 40 hours on the motor from new. I trust his word and the motor also looks to tell the same story.

The motor when cold starts great with three pulls at full choke. It even stays idling right after (which is not as common with a cold start on a 2-stroke). If I desire to speed away with little warm up, I have to use partial choke to get past a dead spot in the throttle, and then she flys! To also note, it actually picks up speed at WOT if I use some of the choke. Then after about 7-10 min at max throttle (with or without the choke), the motor starts to sputter, misfire and pop like the sound of pop corn and then die. It now takes 5 or so pulls to start back up. Now that the engine is warm if I rev up the motor out of gear, it will do the same and die. Choke at this point does not help starting or keeping the motor running at WOT. It does however help with the dead spot (around 1/3 to 2/3 throttle) especially if I manually choke it by putting my hand over the air intake. I can troll for hours and the motor never misses a beat. Turns off like it should and on with one pull starts! I just can’t go faster than 1/3 throttle.

So far I have cleaned out the fuel tank and used fresh gas. I have also opened up the carb but found it very clean! As it was clean and I did not have any compressed air, I did not do anything to the jets. When driving, the primer bulb is always firm and squeezing it when the motor is acting up does not make a difference (it might hurt performance). From the word go, there is always a healthy stream of water flowing out of the motor.

Any advice or wisdom that can be offered would be greatly appreciated!
Thanks for your help
Darryl

[jeff_smith_0423]

I would start with a true carb cleaning to rule it out. If i were you I would obtain a factory service manual for your motor - it's a rebadged suzuki. Generally recognized as pretty good motors. You may get more responses in the Suzuki forum as this area tends to be pretty 2stroke oriented.