I'm losing speed...

[blue92]

I've got a 15' ebbtide getting pushed by a merc 60. I used to be able to cruise around 26mph when I first launched it. I left it docked in the water for a few weeks and the barnacles just went wild. They covered the entire bottom of the boat and a good portion of the lower unit (the trim motor is broken). I took it out of the water recently and scraped about half of the barnacles off. I put it back in the water to see what it would do and I couldn't top 15 mph.
Now I know the barnacles are causing me to lose speed, but would they account for a 10+mph decrease? Or, is there something I should look at on the motor? Also i might add, the motor sounds strong and it has a good holeshot but the boat just won't top out like it used to.
I appreciate any input.

[irish jig]

Barnicles are killers. Is you lower unit submerged all the time? Maybe you have obstructed water flow.The barnicles get everywhere!

[blue92]

Yea...the lower unit was submerged for the few weeks that the boat was in the water. It's out of the water now. From what I can tell, the water seems to be flowing as it was when I first launched it.

[flycatcher]

Is the boat getting up on plane? If your trim is down too far you may be plowing and not getting onto plane which will kill your top end.

[blue92]

It planes, but not like it used to. I'm going to set the trim at a different level next time I'm out, but I really think there's something else holding it back. I also just scraped the rest of the barnacles off, so hopefully I gain some speed back.

[blue92]

Well... now it doesn't want to start. I just had the carbs rebuilt last week and it ran good the day I got it back. Now it doesn't want to start again, I'm thinking I may have overprimed it and possibly flooded the carb. What should I do? I read somewhere that I can spray WD40 straight into the carb to start it up. Any input?

[Grady23]

DON"T use WD-40 in the carb -- it won't help and will likely cause more problems. Pull the spark plugs and spin the engine over for a few seconds to clear out any gas left in the cylinders. Replace the plugs and try again. you shouldn't need any more than a few seconds of ckoke for the engine to start. Be sure you have the muffs on and a water supply to them or you'll destroy the water pump impeller.

[gary49]

When you flood an old two stroke carbed outboard, what you do is to open the throttle all the way and then crank it. When it fires, pull it back quick to keep from over-revving it. Like Grady 23 says, if you have flooded it really badly, you have to pull the plugs. Sometimes you even have to clean the plugs. It is easy to flood a carbed two stroke, I probably manage to flood at least one of my two motors at least slightly every other time I start them cold. The barnacles are absolutely deadly on boat performance, you have to either paint the bottom with anti-fouling paint or only leave the boat in a day or two at a time if you expect to keep them off the boat. You should be tilting your motor out of the water whenever you aren't using it, the lower unit is aluminum and can corrode, is subject to electrolysis, and gets covered with marine growth if you don't.