Limit of my exhaust and carbs

[michaud321]

over the winter in a few month ill be rebuilding my motor

i was thinking an aggressive trail/mx port job

or maybe a 4mil crank with a 4mil port job,

if my cylinders need it i might resleeve them bigger or a get aftermarket cylinder

 

but i was wondering how far i can go before i will need to upgrade my exhaust and carbs?(fmf fatty's and 28mm PWK)

 

i know i will gain from upgrading to 34-35mm carbs with a good port job, but im worried about loosing too much bottom end,i dont mind loosing some bottom end but i DONT want that light switch power that i keeping hearing about from the cub cylinders,i dont really know much about the diff exhaust.

because i still ride some trails(3rd-4th gear trails) but i also like ripping down roads so im not real sure what to upgrade,

 

sorry im having a real hard time trying to explain myself, im not even sure if i asked a question

[jbooker82]

I would say your good to go as is.

 

Trail or MX port is going to be a low to mid range port job so you pipes will be fine, weather you do a 4 mill or not. Those carbs you have will aslo be good. I wouldn't go to a 33mm pwk unless you get a dune port job.

 

A 4 mill does gain you more mid range, so you could get a more agressive port job and still have more or just as good of a midrange as a stock stroke trail port. That way instead of being all low end it will rev out more, but still maintain a decent mid range.

[RagunCajun]

my ported 4 mill ran awesome on stock carbs. You are good to go. It's mostly a preference. Might get a little more top end from bigger carbs. Whoever is porting your jugs should be able to help you out on that.

[michaud321]

thanks guys

i thought that my top end will suffer

 

how much more noticiable power will I get out of a 4mil with a 4mil port job compared to a stock stroke with a good port job?

[jbooker82]

A ported 4mill will give you a stronger midrange than a ported stock stroke.

 

With at extra midrange you have 2 options. Keep it by getting a trail port and have a strong midrange motor. Or give up some midrange in exchange for top end by going with a dune port job.

 

I would say option #2 is what I would do since you ride mostly in 3rd or 4th gear.

[RagunCajun]

Correct me if im wrong:

 

4mil gives about 10% power all around. Also doesnt it move the power curve as well?

 

I personally noticed the powerband came on more smooth too. I cant comment on the power increase of the 4mil crank because i did other mods when i stroked my engine.