how and what parts would i need to get lots more top speed out of my bike, i know than its a combo of RPM's and gear ratio, its 4x4 so i can't change the gearing really.?. how would i make the motor rev higher, would a big bore like a 440 be a big difference in top speed, i plan on getting it ported sooner or later prob next year if the moneys around. BTW i just got the AAEN top end pipe and clutch kit and boyesson reeds and dam its a new freakin bike wow the wheelie power lol. thanks if u must knowi kinda want my scram to keep with a raptor 660 in top speed, bragging rights and polaris pride lol!

 

Porting,mill the head and go with either a PWK39 or Mikuni 38mm flat slide

 

thanks again Ftwflh, on the scrambler how do u build more RPMs ? would a big bore kit be a big help overall or just a big whole in my pocket, what are companies that sell whole kits like the ones from AAEN i know rick ritter has a website have been there, do u know any others? would doing more tuning to my top end hurt my bottom end power, i love the bottom end with this pipe and clutching

 

Exactly what ftwflh said , porting is huge on the 400 same with the carb 39 PWK. You can trail ride a race port if your a good enough rider. But not for the novice. IF you want more RPMs out of it now and to match that pipe you have. Get a AAEN RED or a HPD Red/Yellow primary spring. Get a HPD voilet secondary spring set at 1-1 or a AAEN Blue secondary spring set on 1-1 as well. The Primary springs will spin to 7500 rpms but you really need to flow that jug to spin it that high.

 

thank you so the pwk carb is better than the mikinu 38mm, and i'm a good rider i could probably take the guy on the trails its just being able to hang with em on the flat straights would be great, and back roads, does any one know about the AAEN 440 big bore kit, would they send you a new cylinder or do u send them yours and they bore it, and also has anyone from canada used rick ritter? i know hes great its just the mail and what not. And whats the difference between trail and race porting is it just the drasticness of it or what?

 

With the Aaen Topend pipe stay with the clutching they recomend because it gets you close to where you need the rpms to be to match the pipe.Trail porting will work best with the Aaen pipe that you have.The 440 kit will get you more low/mid range and cut cylinder life to 2 maybe 3 bores.
On the carbs the PWK is easier to get dialed in where the Mik 38 takes some time to get the mid right.
On trail vs race porting race porting changes the timing curve wher trail port stays closer to stock.Things get intense when tuning for race porting things have to be more persise than with trail porting.As you can see I am not into the race mods for a trail machine.
What you have add the trail port,a good carb,Boysen RAD valve,a TEAM roller clutch.And keep your rpms around the 6850 that the pipe is rated for not anymore and you MAY be able to get by without a girdle kit.The more rpms you turn the better chance of the cylinder letting go.

 

ok thanks, few questions after a weekend or riding, with the aaen pipe and boyesson reeds the mechanic threw in a 260 jet and thats it, about half way threw the weekend it wouldn't idle and was running rich. i changed the airfilter and fuel filter during the weekend and it didn't help, also what is the compression supposed to be on this bike?