strange jetting rpm issue By millsc (Read 438 times)

[millsc]

i checked my plug with the 100 jet with my 24mm carb, and it looked a little lean. So i put in the jet that came with the carb in it out of curiousity. Took it for a ride and before it ran 7500 rpms at full throttle which i thought was perfect, after the jet change the rpms windout to almost 9k and its faster, not sure why and maybe i need to keep that jet in there and up the weights, or should i leave it be?

[Alleyoop]

If its a 4T put in heavier weights those are to high of rpms for a 4T, at those rpms it won't last very long the redline on 4ts starts at 8000k. You want to run like before around mid 7Ks or little lower at WOT. If its a 2T then it is a different story they make their power at high rpms.
Alleyoop

[millsc]

wonder why it changed after the jet switch?

[Alleyoop]

Do you know what size the one you switched is? If it was a 24mm carb they usually come with a main jet anywhere from 103-107 so your 100 was lean.
Alleyoop

[millsc]

I have no idea what jet it is, it was unmarked, was running a 100 main jet before.

[Alleyoop]

So like I said your 100 was Lean.
Alleyoop

[millsc]

ok i have some 10 gram weights, i'll put those in to stay under the redline

[millsc]

i settled in a 9.5 grams i was running 9.5 and 9 gram mixed and after jet change i went over 8k at wot put the 9.5 set in and it maxes around 7.6k rpms i'm comfortable with that, even though it was slightly faster at over 8k.

[Alleyoop]

That sounds good mills right on the powerband of the 4ts.
Alleyoop