1980 35HP johnson. Carb Rebuild?. Reeds?

Engine has 125 compression on both cylinders, Starts easy from cold. Idles perfect and runs wot perfect, But from about 1/3rd throttle to just past half it is very rough and only hits on one cylinder.

Whats it sound like to you. Carb, Reeds or maybe something else?

do you have a spark tester to see if it is firing in that range?

could it be that the system has a worn wire that is opening, or more likely shorting when in that range?

No I don't have a spark tester. Sounds pricy though.
Forgot to mention it has new plugs also. Champion ql77 something or other. Don't remember right now.
I suppose what you mention is possible but it is a outboard and anything can happen no matter how odd it seems.

you can get an inline or a gap tester at the local auto parts store. They usually run around 5 bucks.

OK so barrowed a tester and running in a barrel there is spark. So I'm thinking it is carb or reeds?.
I have a carb kit but if its reeds would like to do them at the same time. Thoughts?

I would try carb rebuild kit...reeds usually let fuel blow back out carb...if they are not sealing off.

Thanks. Had not even thought of that. Went and looked. I do not see anything that looks like fuel blowing back. I'll try the rebuild kit tomorrow night and report back for future reference!

Ok rebuilt carb today and found there are 4 little holes above the butterfly. 1 was plugged by what looked like green dried gas and the low speed needle was turned out about 10 turns!! Probably from the PO trying to compensate for the mid range miss.
Anyway Its all clean and ready for a test run tomorrow!

Well its better for sure but I just can't seem to find the sweet spot for the low speed needle.
Slight miss just off idle.
Tried 1 turn rich/lean seems to have no effect after getting it close as I could so I'm out of ideas

Final notes.
Finally got it dialed in. Did a link and sync per the manual and adjusted the low speed needle 1/8 turn at a time.
Engine now runs fantastic!
Its actually amazing how simple Johnson engines are. Had a 75hp merc years ago that never ran right no matter what I did and totally turned me off 2stroke outboards always had to be tinkering with it even if it started out the day running great

Now though with this Johnson its totally different how nice it runs and seems to sip fuel. Just launch the boat hit the start button and it does its job. ALL DAY LONG!

Good job and thanks for the update. Enjoy!

Thanks for the update the little 2 cylinder with one carb Johnson and Evinrude motors are some of the easiest to work on and the 35 hp is one of the best in weight to hp ratio. Glad you got it running right.