78 35 up johnson wont run past half trottle

[Duckfool87]

I have a 1978 35 hp johnson electric start that starts up and runs great till I got just over half throttle. At that point it starts bogging down till it eventually dies. If I go past full throttle and its doing that I can throttle back down to just inder half throttle and it goes back to running normal . I've put brand new plugs and wires in it. Carb has been pulled cleaned and rebuilt .Any ideas what migjt cause this.

 

[oldboat1]

fuel pump? Try using the primer bulb when it acts up.

 

[racerone]

Do you have spark on both leads ?---They run quite well on one cylinder.

 

[kbait]

If primer bulb test doesn’t help, and it’s running on both cylinders, main jet in carb is likely partially clogged. Choke it quickly when bogging to confirm (it will speed up briefly).

 

[Duckfool87]

I have tried squeezing the bulb with no effect. I will try the coke thing this evening. If that's the case i will go back thru the carb.

 

[oldboat1]

Before more carb work, though, at least pull off plug boots one at a time. If no change in rpm, that plug isn't firing. Using a tester, you really need to measure to see what you have.