Bogs Down at WOT

[FJ_Russo]

I have a 1974 50hp Evinrude. When I run the engine at WOT it just completely bogs down. Starts nice, idles with a little chugging, then at about half throttle its just like I backed the throttle off instead of gave it more. If I run it with the choke on as soon as I let up she revs up. I did a carb rebuild and cleaning, new fuel lines, new fuel pump. So I'm stumped what do you guys think I should look at next? My beautiful girlfriend is tired of sunnin herself in the driveway.. and said she would really like to see how the sun is in the middle of the lake

 

[glassmaster68]

Re: Bogs Down at WOT

there is alot of things that can go wrong with those same symptoms.i would check and recheck that carb,esp high speed jet or oriface.make sure you have enough fuel going to the carb from fuel pump and make sure youre using a pretty new primer bulb hose,those ...as simple as they are can cause the same thing,,,,,you also could be running on one cyl,,,check that you have adequate compression then fire to both cyl first,then go from there.

 

[FJ_Russo]

Re: Bogs Down at WOT

Thank you for the tips! It is running on both cylinders, I have done so much to this engine I forget sometimes. I have pulled the plug wires on both the top and bottom cylinder and they both stay running. I checked the compression and I have 140, and 143. I have a brand new bulb and gas line all the way from the tank to the Carbs. I think I will try pumping the bulb next time I'm out when I'm at half throttle to make sure its pulling enough gas. I'm definitely not an expert at carb cleaning, I have only had apart one set of carbs and these are it. Just followed the directions on here. So I'm not saying they are definitely 100% clean

 

[outlaw241]

Re: Bogs Down at WOT

i had same problem before an it was the nozzle gasket was booger-ed up,a small flat o-ring with three tabs on the inside,it slides on the carb through the center of the float,if it is booger-ed up it will let it suck air above the float level instead of fuel below the float level at wot, it is a cheap fix for the lady to get some fun in the sun.

 

[FJ_Russo]

Re: Bogs Down at WOT

I'm definitely possibly missing the part your talking about. Is there a way you could look at the schematic I have hear of my carb and tell me what part your talking about?

http://www.boats.net/parts/search/BRP/EVINRUDE/1974/50473M 1974/CARBURETOR/parts.html

 

[FJ_Russo]

Re: Bogs Down at WOT

Yeap definitely missing this part. I have the gasket between the bowl and the carb. But I do not have a small ring gasket... I think. Where is this part supposed to go? I have found the parts on i boats #181241 just not sure does this just slide ontop of the jet?

 

[outlaw241]

Re: Bogs Down at WOT

part # 39 in your diagram, it seals the raised part in the center of your carb bowl to the carb an it slides on down through the center of the float.