How much do non-stock parts change jetting?

[winchcable]

I have a few questions about jetting.

If you were to take a stock 2-stroke and put on a Pro Series pipe, what kind of change should be made to the jetting? What if you have a stock 2-stroke and change the reeds? I know these are hard questions to answer without knowing what bike or what parts or what temperature or elevation etc... but I am looking at baseline type of stuff.

By putting on a different pipe does it make it generally richer or leaner?

By putting on different reeds does it make it generally richer or leaner?

You get the idea.

If I am supposed to be running a 168 main jet for a given temperature, elevation and humidity, but I only have a 170, can I raise the clip on the needle and be close?

I have my bike running good right now but I am looking into the fine tuning of it and trying to understand it all.

Thanks

 

[bikepilot]

Pipes and reeds don't generally change the fuel mixture much. What do you mean that you are supposed to run a 168? If a 168 is ideal, then a 170 will be very slighly rich. Moving the needle to compensate will make it too lean at part throttle, but it would still be too rich at full throttle.

You can not really go by any jetting chart. Every combination of bike, rider, conditions places a unique demand on the jetting. Don't worry about what the chart in the manual says, just jet it so that it runs well for whatever you are doing with whatever mods you have.

If I were installing another pipe, I would leave the jetting alone, go for a test ride and make changes as necessary depending on how it ran. There have been plenty of posts describing how to properly jet a bike, try a search for starters.


good luck:)