Should I rejet?

[Budget_Blaster]

This is on my banshee.

I have chariot performance billet reed cages with boysen pro series reeds,Toomey T5's,And now a K&N.My question it with uni 2 stage foam filter and a 280 main,27.5 pilot,1 3/4 turns on a/f,stock needles in the mid clips,it ran perfect but i then found out the coolant was wicking up the threads of one stud so i ripped it all back apart lapped the head,polished the chambers and put it all back together upon doing so i added the K&N filter i bought that still uses the stock air box with no lid should i go up a jet size or will the K&N flow enough to make a harmful difference on jetting?

I literally have no ride time on it now that it together i fired it up that night for 2-3 mins and it ran great but ive not rode it.Kind of dont want to until im sure im not going to do any damage.I also found out im 679ft above sea level (ALWAYS THOUGHT I WAS AT SEA LEVEL) if that matters.I only have one jet size up to go without visiting jets r us.com again.I also dont ride if its below 70 out.

What do you guys think?Need a rejet or should i leave well enough alone?As i said before the coolant issues it ran awesome all i changed was the filter to a k&n.

 

[Blaaster]

2 words, plug chop.

That will tell where your jetting is at.

 

[Larry's Shee]

If it were me I would throw the larger jets in then plug chop. K&N will flow slightly more air. 2 plugs are cheaper than 2 pistons.

 

[Budget_Blaster]

If it were me I would throw the larger jets in then plug chop. K&N will flow slightly more air. 2 plugs are cheaper than 2 pistons.

What size do you recommend?

Im going to grab some 300's and i already got 290's which do you feel would be better?

 

[Blaaster]

It is always a good idea to grab a few extra sizes, above and below, because as sure as eggs are eggs, the ones you don't get will be the ones you need.

 

[NOVIS]

that one thing i definitly DO NOT miss about my banshee. theres 2 of everything

 

[Budget_Blaster]

I picked up 300's a few mins ago so i think 270-300 should put me in the ball park.

I got 280's now and they feel pretty good as is but im willing to give up a few ponies for longevity.

 

[Budget_Blaster]

Oh yea forgot to mention the stealership gave them to me for free and theyre genuine mikuni jets!!!

Nothing crazy save since they charge 8$ a peice but hey 16 bucks is 16 bucks!

 

[Blaaster]

I picked up 300's a few mins ago so i think 270-300 should put me in the ball park.

I got 280's now and they feel pretty good as is but im willing to give up a few ponies for longevity.

Smart move, one size jet may save an early trip to the bank!

 

[Budget_Blaster]

Well i rode it for an hour or so and i dont know that i need to mess with it.

The plugs are a tan cardboard color and is running hard!!!

This things is a beast!

after an hour of ripping up and down foield acess roads with no bogging popping and the plugs looking so good i think i may just chop it and see.worst case scenario is i have to rejet.

Idk yet i may throw the 300's in and see how it runs.I prefer rich as a cushion of safety just in case something happens.

 

[Larry's Shee]

Didn't say if your rip was with 280s or if you upped it one size.

 

[Budget_Blaster]

280's bro aint changed jack yet and dk if i should?

 

[Blaaster]

Its only 10mins and $10 to put you on the safe side.

 

[Budget_Blaster]

Its only 10mins and $10 to put you on the safe side.

Yea i know 300's are going in tomorrow or tonight depending on if i can sleep or not.lol

They say things start to run really good just before they blow up and this things screaming!

So i spent the 30 min trip to town to get jets damn it i might as well throw them in!

 

[Blaaster]

Yea i know 300's are going in tomorrow or tonight depending on if i can sleep or not.lol

They say things start to run really good just before they blow up and this things screaming!

So i spent the 30 min trip to town to get jets damn it i might as well throw them in!

Hereyby lies a major problem, a motor running slightly on the lean side will perform beyond all expectations.

It runs like a cat with a firework up its clacker, then bang.

This is the reason one must do a plug chop to confirm that it is not on the lean side.

It is just about impossible to diagnose a slightly lean fuel/air mix by the issue of smoke, by listening, or by feeling for performance.