[mmf]

1968 Merc 500 (50HP) serial #2407450, my carbs on this motor have alot of wear. I have 3 Tillotson KC7A carbs in good shape from a 1969 Merc 115 engine. The 115 carbs have 0.066 jets while the Merc 500 carbs have 0.063 jets. The bore on the 115 carbs is a little larger than the 50HP carbs too.
Do you think I will run into any problems running the 115 carbs on the 50HP engine if I change the jets to the 50HP size??
Thanks!

[Yepblaze]

I've never really taken any of these old merc carbs out of service for wear.

But that being said, it sound like you have a plan.

Let us know how it works out.

[mmf]

sorry for the very late update but the carburetor change worked great!
Idles perfect, and good high speed operation. Thought I might run into a little air turbulance problem due to the larger venturi bore but that never happened.

[troubledboatdude]

i have a 70 500 50 hp...im wondering if you can help...just got it, it was running great at idle and wide open but seemed to lack fuel inbetween. now 1 week later runs great in neutral but when in gear seems to starve for fuel if i can feather it nicely a little tap on the choke button will keep it from starving, it will go smoothly in gear at idle...has great spark lots of compression (top 120 psi,2nd 120 psi 3rd 120 psi, 4th 122 psi)...and if it is carb i used to be an auto mechanic but never touched one of these,how do i get the carbs out of this? (im very sry to post this question on your post you just seem fairly knowledgable in this area)