1997 200Hp Johnson Ocean runner carb jet question

[mike66]

Hello all. First post, just discovered this site. I'm not a racer, but having trouble with my new to me J200TXEAU. It was idling poorly, surging and misfiring at idle up to about 3500rpm, then would take off up to 5500 smoothly. I have gone over the systems using the shop manual, and found all 6 exterior check valves in the recirculation system open (no valve) and all six internal valves missing. Obviously someone had been inside this motor. Anyway, set all up by the book, link & sync, etc. Idle timing at 4 ATDC. runs much better, but still searching a bit at idle (1000 in neutral, 650 in gear), and the range from 1000 to 2000 is rough and surging. Stock low air jet is 27. I'll verify that today. Any suggestions on a jet to run richer through that range? Anyone willing to loan me some different sizes to try? Thanks for any help.

[racer]

Original 97 carbs have an adjustable idle needle. Start at 5 and a 1/2 turns out. Should be TXEUA not TXEAU

[mike66]

You're right. Typo, EUA. 51/2 is where I started with the mixture screws. I went +/- a half turn with each carb individually but couldn't really detect a difference. I'm going to go over it again looking for air leaks. How many turns should I go on the mixture screws before giving up?

[mn808gade]

seem's 7-71/2 in heat of summer is about what I end up setting them at ---(normal??)-th

[mike66]

Thanks. I just replaced the cam follower, the outer part was broken off. My setup must have been off though, because it ran worse afterwards. Stalled out a couple times trying to dock. Re-checked the idle and sure enough, the timing was retarded too much. Brought it back to 4ATDC and it idled fine, but still a misfire/sneeze. More work (playing around) to do today. Looks like the mixture screws have a wide range.. If I go from 5 1/2 turns to start out to 7 1/2 in 1/8 turn increments X 6 carbs, it's gonna take awhile.

[racer]

If you had set your timing before and now it was different make sure the ctr hub has not moved. Go 1/4 at a time till close.

[mike66]

Did a thorough link and sync today. 650 idle at 2° ATDC. Much better. Still a bit rough below 2000, but maybe I expect too much. Settled at 5 turns and gave up for now. Thanks for all your help, appreciate it.