michaud321 Posted August 8, 2010 Report Share Posted August 8, 2010 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 Quote Link to comment Share on other sites More sharing options...
jbooker82 Posted August 8, 2010 Report Share Posted August 8, 2010 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. Quote Link to comment Share on other sites More sharing options...
RagunCajun Posted August 8, 2010 Report Share Posted August 8, 2010 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. Quote Link to comment Share on other sites More sharing options...
michaud321 Posted August 8, 2010 Author Report Share Posted August 8, 2010 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? Quote Link to comment Share on other sites More sharing options...
jbooker82 Posted August 9, 2010 Report Share Posted August 9, 2010 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. Quote Link to comment Share on other sites More sharing options...
RagunCajun Posted August 9, 2010 Report Share Posted August 9, 2010 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. Quote Link to comment Share on other sites More sharing options...
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