I have a bf40 that starts and idles well, however when shifted into gear and put under load it stalls out. The only way to get it to rev up to higher rpm is to trim the motor high, which reduces the load at the prop. This is not my boat (mother-in-laws), but was lent to me for the summer to enjoy. It has sat for the better part of 4 years and used less than a hand full of times, I was told the carbs had been cleaned last year, but likely sat for a year with no stabilizer. I have tried a liberal amount of seafoam with no success. I assume the carbs are completely gummed so i pulled them off lastnight (reaked of old gas) and am planning to soak in a carb bath for 2 days. Hopefully this works.
Thoughts?

Another issue i ran into, was when disconnecting the lower arm off the bottom carb there is an arm that connects to the same assembly and a cylinder with an arm on it as well that connects to a plastic holder that also connects to the main assembly. Sounds very confusing, but if you have had the carbs off this motor you should have an idea of what i am talking about. My question is, how does it connect properly when re-assembling? It popped off when removing lower carb and arm and I don’t have a manual. Pics would be great!