Johnson 25 shudders above half throttle

[tom blanchard]

I have just aquired an older

I have just aquired an older 25 HP Johnson Seahorse electric start OB. It starts and idles great. It goes smooth up to about 1/2 throttle then about every 6-10 seconds it shudders (it shakes the boat) but only for an instant. There is a vertical lever (@8"long) on the stbd side of the engine that moves in and out when it goes in and out of gear. I think I saw that lever pull in for an instant when the engine shudders. I plead complete ignorance. Please help.

 

[john]

lower unit check fluid

lower unit check fluid

 

[larry]

check your shifter linkage so

check your shifter linkage sound like the 8" thingy on the stb side. may just need a small ajustment.