Hesitation

[Dusky Mike]

1994 150hp Evinrude OceanPro...I hit the throttle to wide open from idle (like you would if you were pulling up someone water skiing). It didn't respond for about 3 seconds, then brought itself up to plane. It sounded a little rough at first, but ran okay after that. Not the first time this happened. I just got finished running seafoam through it (that is, this was the first throttle up of the trip).

Also, in recent trips, the engine has been coughing, or hiccuping while up on plane. This didn't happen today (which is when I added seafoam, coincidence?). I am going to try to remove the anti-siphon valve as suggested, but need some instruction on where it is and how to get to it. Any thoughts on this.

Lastly, I am new to this forum. Thanks so much for all of the help!! I like the layout of the site, and I plan to stick around for a while! Thanks in advance...Mike

 

[tashasdaddy]

Re: Hesitation

mike i think you need to consider the carbs, possible fuel flow restriction, or the link and sinc. this is the syncronization of the spark advance and the carbs opening at the right time. even a possible weak fuel pump. if your are going to work on this yourself you need the oem manual, either from kencook.com or from ebay. get the number you need.
http://www.kencook.com/evinrudejohnsonmanuals/

 

[ezeke]

Re: Hesitation

Most anti-siphon valves used a spring-loaded stainless steel ball bearing with a collar to retain it.. It was usually located at the top of the built-in tanks and the fuel line connects to it. So, it is the last metal connection on the way out of the tank.

The anti-siphon valve was a Coast Guard requirement when the fuel line or engine was below the top of the tank, so that the fuel would not be siphoned out of the tank if there was a leak in the engine carburetors, fuel pump, or fuel lines.

The changes in fuels have made many of the valves worthless and problematic. Unlike inboard fuel pumps, the outboard fuel pumps are not designed to overcome the extra load. If the fuel lines and engines are above the tank, they are not required anyway. They are very easily clogged.

So, if the conditions are such that you are not required to have it, you can push the bearing out of the connector and eliminate the problem, or, replace it with the newer one that is designed for the fuel we are now using.