Hello All,
I have a 1990 Evinrude 150 on a 1990 21' Kenner Center Console.
This weekend I finished a moderate overhaul of the engine: rebuilt carbs, pulled heads, replaced head gaskets and head cover gaskets, cleaned the exhaust chamber and replaced the gaskets.
Then I found the real issue, the fuel line between the bulb and the engine had a small hole in it. So that got replaced.
I put it in the water Sunday morning to test out it.
Ran great up to 2400 RPMs. The boat would plane and run nice and cool and smooth all day long.
But, when I pushed it up to 2500 rpms the engine would go from a smooth pur to a rythmic vrum, vrum, vrum, vrum, vrum . . . with no speed gains. Almost sounded like it was missing.
I'm guessing its either a fuel restriction or ventilation.
I ask because I have no idea what ventilation actually sounds or performs like. I will also say that the motor is mounted quite high on the transom so that the anti-ventilation plate is above the bottom of the boat.
The one thing I didn't do at the time was trim the motor all the way down. I was thinking it was bad gas or some kind of engine related issue.
Also, the onboard 60 gal gas tank was about 3/4 full of old gas. I put some seafoam and sta-bil plus fresh gas to top it off. ( I know that they don't really help with already old gas, but what am I going to do with 50 gal of bad gas?)
As soon as I would tap the throttle back to 2400 the engine would settle down and pur. Also, at 2400 rpm it would turn fine, although I didn't try any tight turns.
One more thing, as I was reading some other posts looking for answers I came across a note that some evinrudes could melt part of the stator and you would see some goop dripping down. I have what appears to be some goo on the engine below the flywheel, above the carbs/intake. The battery leads show over 14v when running.
Any ideas? Does this sound at all like ventilation or should I focus back on fuel delivery and spark?
Thanks!
I have a 1990 Evinrude 150 on a 1990 21' Kenner Center Console.
This weekend I finished a moderate overhaul of the engine: rebuilt carbs, pulled heads, replaced head gaskets and head cover gaskets, cleaned the exhaust chamber and replaced the gaskets.
Then I found the real issue, the fuel line between the bulb and the engine had a small hole in it. So that got replaced.
I put it in the water Sunday morning to test out it.
Ran great up to 2400 RPMs. The boat would plane and run nice and cool and smooth all day long.
But, when I pushed it up to 2500 rpms the engine would go from a smooth pur to a rythmic vrum, vrum, vrum, vrum, vrum . . . with no speed gains. Almost sounded like it was missing.
I'm guessing its either a fuel restriction or ventilation.
I ask because I have no idea what ventilation actually sounds or performs like. I will also say that the motor is mounted quite high on the transom so that the anti-ventilation plate is above the bottom of the boat.
The one thing I didn't do at the time was trim the motor all the way down. I was thinking it was bad gas or some kind of engine related issue.
Also, the onboard 60 gal gas tank was about 3/4 full of old gas. I put some seafoam and sta-bil plus fresh gas to top it off. ( I know that they don't really help with already old gas, but what am I going to do with 50 gal of bad gas?)
As soon as I would tap the throttle back to 2400 the engine would settle down and pur. Also, at 2400 rpm it would turn fine, although I didn't try any tight turns.
One more thing, as I was reading some other posts looking for answers I came across a note that some evinrudes could melt part of the stator and you would see some goop dripping down. I have what appears to be some goo on the engine below the flywheel, above the carbs/intake. The battery leads show over 14v when running.
Any ideas? Does this sound at all like ventilation or should I focus back on fuel delivery and spark?
Thanks!