I recently purchased a Rotax runs rough when on the throttle, I am assuming that perhaps its the jetting? Anything else that I should look at it? I have taken apart the carb to check the settings.
Also the radiator I have on it is in rough shape pictures it holds water, unfortunately I don’t have a leed for the head, I do however have water temp leed if that would be helpful in evaluating.
This almost sounds like the choke is stuck on. Looks like the lever is down, but it sounds way too rich. What jets installed? What float height? What needle position.
Good starting point is normally around 125 main jet. 3mm float height, and needle position 2.
Make sure the floats are free to move. There is a small screw just under the fuel line inlet. Sometimes there is a filter. If there is throw it away. Check you fuel lines and inline filter.
Also plug can just foul on the Rotax very easily if you idle for long on the stand.
It runs a lot better with an airbox installed.
And make sure the powervalve is clean and not sticking…
Rotax never runs good enough with out a proper rotax filter box .
Dont ask how i know it . Start from there
Can confirm, never run it without the the original airbox. Would slso suggest tu use the original filter
I’ve never had one run that rough on the stand without an air box. It should still rev out. Done it plenty of times warming it up on the stand without an air box.
But yes of course on track run the correct air box and filter.