S200HP Carb

[SeaOx1988]

At what RPM does the main jet com in? It seems at 3500RPM my motor runs rough but above that runs OK but wil only run at 4500RPM WOT.

[TownsendsFJR1300]

Main Jet

The main jet affects all of the throttle opening but specifically takes over from approx 1/4-1/3 throttle and up.. The idle jets, etc are nill at the higher RPM's..

If it won't pull over 4500RPM, your carbs are likely gummed up with varnish... You might be able to get by with running a heavy does of Seafoam (cleaner/stabilzer)and/or Cheveron techtron(more a cleaner).

At the very least, there should be a drain screw at the lower end of each float bowl. Drain each carb into a small container (I use a very clean tuna fish can). Look for debis, water and smell it to check if the fuel is stale.

Without additive, regular fuel will foul in a month...

If the additives don't help, I suspect you'll be pulling the carbs and cleaning at least the lower end of the carbs where the jets reside...

[edwardpaschall]

main jet

First off you should run Yamaha Ring Free in your fuel at all times also a good fuel stibilizer such as Star-tron. Because of the fuels that we all run today there are problems with algue grouth in the fuel systems and carbs. They don,t make a mechanic in the bottle where we just pour something in our fuel systems so we have to treat our fuel with special additives. Second the best way to fix your problems is to have your carbs. rebuilt and install a fuel/water seperating fuel system to help with this problem.It will cost $$ up front but in the long run it will pay off