Rejetting after new exhaust

[ImNewToThis]

Hey guys. I just got my first banshee and need some help. It’s currently running an Athena 400 complete big bore kit that was bored to 421   Its currently running a 380 main and a 27.5 with a plus 4 timing adjustment. I wanna switch up the exhaust to change the look of the bike but don’t have any idea of what I should start with for Rejetting   Any help is greatly appreciated 

[locogato11283]

The 27.5 pilot is right for almost any aftermarket exhaust. In some instances if it's really cold near sea level, you might need a 30.

That main jet is too big. Most setups like yours will take somewhere between 290-320.

How does the bike run? Does it fall flat on the top end?

Have you looked at the color of the plugs?

[ImNewToThis]

Yes. The bike runs amazing. She does run a little rich but not horrible. The previous owner ran it on 110 for the couple times he rode it and gave me the rest of the barrel with the trade I haven’t opened her up very much. I thought I would be chilling because I had the crotch rocket but this is just a completely different beast. This may sound stupid but what do you mean by fall flat? Like just start choking itself out like to much fuel? And plugs were fine but what colors do I need to watch for? I know to watch for black or dark brown for fouled plugs and what not I also live in WI and plan to ride her around a bit this winter. I also need to rejet for that too, right?


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[locogato11283]

Falling flat means that you'll get good pull through the mid-range and then it just kind of slows down up top.

I'd do a wide open throttle plug check and see what the plug straps looks like.

You want them cardboard color.

[ImNewToThis]

Ok ok. That makes more sense thank you. I’m gonna take her to my buddies land and trails this weekend and really just let her eat. I just did some research cause I was unfamiliar with the terms you used I got it now tho. From what I’m seeing I should go buy new plugs and then run about a 1/4 mile and then shut it off. I found a whole article breaking down what to look for on the plug A lot of this seems complicated at first but your breakdowns and all the others I’m finding on stuff explain it so well


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[SKEETER]

Install new plugs, run it up to 5th gear wot, and kill switch.   Pull plugs

[locogato11283]

3 minutes ago, ImNewToThis said:

Ok ok. That makes more sense thank you. I’m gonna take her to my buddies land and trails this weekend and really just let her eat. I just did some research cause I was unfamiliar with the terms you used I got it now tho. From what I’m seeing I should go buy new plugs and then run about a 1/4 mile and then shut it off. I found a whole article breaking down what to look for on the plug A lot of this seems complicated at first but your breakdowns and all the others I’m finding on stuff explain it so well


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Correct. Just be careful about pulling the clutch in too long and letting it coast. Run it WOT, kill the motor, then downshift to N as quick as you can. You don't want to weld the clutch ball to the rod.

[ImNewToThis]

Ok. Sweet. Good to know. Had no clue that can happen


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[Jereme6655]

On 12/31/2024 at 2:19 PM, ImNewToThis said:

Ok. Sweet. Good to know. Had no clue that can happen


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Yup it can. Then you’ll really know what a shitty situation is. They sell “pancake” bearings specifically to remedy that. 
 

also…..this site has so much more info on it than most understand. Most things you have questions about can be searched in google by adding in banshee hq after your word…..you’ll be amazed the info that is stored in here.