FMF Pipe Jetting?

Greetings Fellow Board Members!

I just had a question about some FMF pipes and thought this would be the perfect place to ask. So I have a 2003 CR125 with the stock header and an FMF Turbine-Core 2. My question is that I was thinking about getting an FMF Fatty to replace the stock header, but to my understanding you need to rejet the bike after getting a new header? It is currently jetted perfectly and I don't really feel like tearing down my carb since I've done it a lot to get my current jetting perfect. So would I need to rejet it if I got a Fatty pipe? And also I was considering going with the stock header and getting a FMF Shorty because I do a lot of trails and tight woods and want some more bottom end, would I need to rejet if I just got the shorty?

Thanks!

If your jetting is close now, you shouldn't have much to worry about. Over the years I have found that going from stock to aftermarket expansion chambers I usually did not have to make any jetting changes, when I did... it was only a leaner main jet that was needed. If your current pipe is bent / dented and was tuned that way, you might need to adjust a little more.

Shorty silencers dont add low rpm power in my experience. what they do seem to do is add a little bit of throttle response, but I get more low rpm lugging power from either my turbinecore2 or my q-stealth. Either way.... no you should not need to change jetting swapping silencers.

If your jetting is close now, you shouldn't have much to worry about. Over the years I have found that going from stock to aftermarket expansion chambers I usually did not have to make any jetting changes, when I did... it was only a leaner main jet that was needed. If your current pipe is bent / dented and was tuned that way, you might need to adjust a little more.

Shorty silencers dont add low rpm power in my experience. what they do seem to do is add a little bit of throttle response, but I get more low rpm lugging power from either my turbinecore2 or my q-stealth. Either way.... no you should not need to change jetting swapping silencers.

okay Thanks a Ton, I guess I'll keep My Turbine Core and get a Fatty when I have the money…Thanks!

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