Didn’t the previous cylinder heads use smaller jets on the carb? I was told that 125 was a good starting point on the previous cylinder head.
I have a few newer engine packages with the cylinder refresh and the jets that came with them are all 130. They seem to run perfectly. I thought I had read somewhere that the new cylinder heads require larger jets.
If there is a difference in jet size on the new cylinder head, how does that affect the Rotax Jetting app?
What range of jets would be a good idea to keep on hand?
Lastly, how would I test measured value of a jet to compare against the stamped value? Is it that much of a difference if I order my jets directly from Rotax?
Dont you mean cylinders and not cylinderheads?
Jetting is dependent on the thing being Micro,mini, junior or senior.
Regarding jets.
If you dont meassure the size of them, then use the original Dellorto jets, a 130 is In reallity 136 (or there about), what i do is i have a set that are meassured In size and i go from there.
The problem is i Foundation jets that differe In size, all from 4-7 sizes compared to whats stamped on them, and if you buy a different brand you start all over again.
I use a pin gauge set, if you just turning laps then go after whats stamped on the jets, are you looking for the last fine adjustment i would work with a meassured set.
On a Senior 125 do Sound small, but offcause depending on the weather.
If you can get the Rotax jetting app. It’s pretty close. I’m normally just one jet size up or down from what it recommends.
I jet the new cylinders the same as the old.