[HWYSTR455]

The standard 4150s generally come with .097 needle & seats, and will cause lean conditions with more 'thirsty' combos. People throw jets at it and it turns into a pig.

I think the out of box double pumper come with .110 needle and seats, even that can be an issue.

IMO, go right to a .130 or .150, there's no downside really, and since there's more area to seal, it seals better, you can run more psi too.

A lot of people think they need 50cc pumps too, and that's not always the case. Everyone starts playing with cams, diff squirters, and it can quickly get out of hand.

Emulsion bleed tuning really is more useful in drag or circuit racing, when you have some gear more towards one side of the spectrum and specific demands. For 'general' street strip stuff, you can get by with the out of box bleeds.


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