Motor Revs fine in neutral, bogs in gear

[srr5008]

I recently swapped a 98 Evinrude 50hp motor onto my boat. Went through all the usual maintenance for a new-to-me motor - new fuel lines, cleaned the carbs, etc. I've had the boat out 3-4 times with no issues. This last weekend I was running at WOT, and hit a boat wake prety hard and the motor cut out (coincidence??). Now I have no power when the motor is in gear. It revs fine while in neutral, and idles fine in gear. But as soon as I push forward on the throttle it bogs down pretty bad. It isn't running "rough" per say, but I can't get it to go above 3-4 mph.

The only tinkering I did with it this weekend was to pull the carburetor covers off the front of the motor to make sure the butterfly valves were synchronized. I noticed while doing this that the gasket around the carb cover (looked kind of like a shallow airbox, like you'd find on a car) was torn. But I was able to reinstall the carb cover with the gasket in place. Not sure if this would have any bearing on my problem.

Does anyone have any suggestions? I plan to check my spark and compression. I see a lot of online responses to similar questions saying to clean the carbs out. But in my mind, all of these issues shouldn't matter since it is running fine in neutral. I would think that this issues affect how the motor runs in general, and not make a difference as far as whether or not it was in gear. Any help would be much appreciated.

 

[Hooligan Diver]

Search the forum for threads on loss of power under load, or no power under load. Seems a common issue, typically spark related.

 

[F_R]

You should not be revving it in neutral. Other than that, it probably is running on one cylinder. That can be anything from compression to carburetor jet to no spark on one...............or simply a spark plug.

First things first: Troubleshoot. Pull the spark plugs & examine. Test the compression. Test the spark. Pull the drain plugs & see if there is fuel in both carbs. Don't just start tearing into things without an indication that is where the trouble lies.

No that gasket won't keep it from running right. Well it would if a piece of it is missing and got sucked into the reeds. For that reason, you might want to replace it.

 

[srr5008]

Well I've got good compression, good spark, and the carbs looked clean. Checked the linkage and didn't see anything (obvious) out of place. Today I'll pick up new spark plugs and a primer bulb (since mine has some small surface tears - wondering if air could be entering my lines through a small pinhole). Keeping my fingers crossed that the combination of all of these things will do the trick, as that just about covers everything I've been reading in other peoples' posts, on this forum and others.