Re: 9.9 Johnson Carb Question

[David Stanton]

quote fleetwin:

So, does the engine idle OK now? Is this midrange thing the only problem? If idle is still NG, I would look for a different carb to try. If the engine idles OK with a different carb, then we can dig deeper into this carb…

I haven’t worked on it for a week or so, but still have the bad slow idle. I was thinking about, as you also suggested, trying a different carb, but the only similar motors I have to rob a carb from are 15 HP models (have 5 of them from a failed resort) and these are 1989-1991, where the 9.9 is a 1977. My 15s have the larger diameter cam-follower rollers, and the carbs are a bit different, but look like they will bolt right up and can be made to physically fit. To temporarily swap carbs between these motors, will this give me a fair idle comparison? I know the only difference between 9.9s and 15s back then was the carb, but there were several carb changes over the years these were made.
Dave