75hp Johnson (1984) WOT issues...

[kryan2]

rebuilt carbs, new fuel lines, water/fuel seperator installed. Ran great for 1 month.

Now I cant get up to my usuall 5600rpms unless I push the key choke, then it surges to WOT for a moment. I get up to about 4500 only now.

I can push key choke over and over and over and it will stay at 5600....but that sucks!
I squeezed my primer bulbs at WOT and that didn't make any difference. I changed my fuel water seperator and that made no difference. Idle is perfect and when going from idle to WOT it's ok with an occasional "cough"

Any ideas? Wouldnt be electrical would it...key choke makes it run WOT.

 

[Daviet]

Re: 75hp Johnson (1984) WOT issues...

If it runs properly by using the choke, you have a carb problems. I would pull the high speed orifices and see if you have some restriction in them.

 

[JDusza]

Re: 75hp Johnson (1984) WOT issues...

Yup. Look into the carburetor.
To kill time, you could test the fuel pump. Remove the fuel line from the carburetor and wrap it in a rag and turn the engine over. Fuel should be pumped into the rag.
With gas lines removed from carburetors, blow carb cleaner into the main valve and seats. This may clear up any fuel supply restrictions in the main valves / seats.
Try again.
If there's no improvement, you probably have to go further into the carbs' high speed circuits.
Instead of using the choke to keep the engine running, spray premix directly into the front of the carburetors. You may find one carburetor responding more (engine rpms increase) than the other, indicating the bad player.
Good luck.
J