americanmusc1e Posted June 24, 2011 Report Share Posted June 24, 2011 stock stroke welded crank motor on 2nd oversize FMF Fattys HJR Dune Ported Cylinders 19cc swirl-cut domes...... Trinity Stage IV coolhead +4 timing stock reeds and cages stock carbs w/TORS delete cable...... 350 mains...... 27.5 pilot K&N filter with modded airbox I just lost to my friends YFZ450 with a slip-on exhaust (I can get him off the line but he chases me down)........ but I know the carbs are out of sync a little (I think my new cable stretched a little)..... I'm still wondering if something else isn't tuned right though...... I mostly just ride for fun (trails and open roads) and I drag race 250' every other weekend First......... which would do me more good....... chariot reed cages or bigger carbs??? Second....... what size carbs do I need..... I'm trying to be cheap. I have one 35mm Mikuni off of a 2-stroke enduro can I just get one more and run matching intakes or would that be too much carb???? Any other bikes I can steal stock carbs off of??? streetbikes??? Quote Link to comment Share on other sites More sharing options...
WINDYCITYJOHN400 Posted June 24, 2011 Report Share Posted June 24, 2011 We've made 66+ HP on stock carbs. If a 450 with a pipe is beating you....you have bigger problems than your carb size. Time to check if the carbs are even opening all the way. I'm sure with the dune porting your motor would like some 28's or something in the 30-34 sizes. But you should be rocking that 450 as you are. I'm sure I could get that motor in the mid 60's at least. Something else is causing your loss. Find it before you add more changes to your set-up. (AKA - Don't tune to a problem.) Quote Link to comment Share on other sites More sharing options...
americanmusc1e Posted June 24, 2011 Author Report Share Posted June 24, 2011 the carbs are overflowing out the overfills if you let it sit not running..... sometimes one..... sometimes both.... the floats are set to 21mm...... saturday I will put a new needle and seat in both carbs..... and see if that helps..... Quote Link to comment Share on other sites More sharing options...
06specialedition Posted June 24, 2011 Report Share Posted June 24, 2011 Don't waste your money on bigger carbs...you don't need them IMO. Like said above, stock carbs will easily run 65-70HP. My buddy runs a ported 4mil with stock carbs and his bike rips damn hard. I run stock carbs on my stock stroke ported banshee, and I eat 99% of the 450's out here no problem. So if a piped 450 is beating you, something is wrong. Just some suggestions: maybe invest in some chariot or vforce reeds. I'm no expert with fmf's and have never ran them on a banshee, but with your dune porting some CPI's or shearers would help alot IMO. Also, what do you mean by modded air box? If you dont ride in water puddles, I would ditch the whole box and run pods. Quote Link to comment Share on other sites More sharing options...
mopar1rules Posted June 24, 2011 Report Share Posted June 24, 2011 Like said above you should be eatin that 450. I have a '04 yfz450 w/ported head, HMF slip-on, uni filter w/no lid on air box and my banshee w/has nearly identical mods to yours will beat it. You have something wrong. For sure check carb sync. Quote Link to comment Share on other sites More sharing options...
Jereme6655 Posted June 24, 2011 Report Share Posted June 24, 2011 yea yoru having an issue.....either your bike isn't running right or your buddy is hiding what he really has.....there is no way a dune port with 19cc domes should be running you down.....ESPECIALLY if you get the hole shot. His bike should be struggling just to keep you in-sight.... Quote Link to comment Share on other sites More sharing options...
americanmusc1e Posted June 25, 2011 Author Report Share Posted June 25, 2011 I guess I have some issues...... I'm gonna sync the carbs .... check the float levels again..... fix my needle and seat problems..... then race him again today.... If it doesn't get any better I'm gonna start a new thread.... and try to figure out what's going on.... Quote Link to comment Share on other sites More sharing options...
americanmusc1e Posted June 26, 2011 Author Report Share Posted June 26, 2011 (edited) the carbs were still really close..... they didn't really need syncing fixed my leaky carbs with two new needle and seat assemblies........ my Yamaha dealer only had one carb kit in stock (Go figure ) but apparently the needle and seat is the same in a blaster carb so a blaster carb kit did the trick...... the bike runs a little better... but I'm not sure its 100% yet.... I did some racing tonight but it was all screwed up because one side of the track was WAY wetter than the other..... I won against a lightly modded Raptor 600 (he was in the slow lane) and lost against a stock Brute Force 750 (I was in the slow lane)....... now to wash my quad tomorrow I think we are set up to do some runs against the same YFZ on pavement thursday...... that will be the test.... Edited June 26, 2011 by americanmusc1e Quote Link to comment Share on other sites More sharing options...
fastbanshee8 Posted June 26, 2011 Report Share Posted June 26, 2011 (edited) Your gearing is keeping your top speed down, unless you have over sized rear tires. If you can't get good traction, then you are wasting time racing. With a port job, you should be able to pull 14/41 gearing very easy, which is stock. You've got to gear it right, and have traction, or it's over. Edited June 26, 2011 by fastbanshee8 Quote Link to comment Share on other sites More sharing options...
americanmusc1e Posted June 27, 2011 Author Report Share Posted June 27, 2011 I was racing on 22" tires (which return my gearing to stock) except for last night I was racing on my 20" paddles I did a compression check today just for the hell of it...... 170psi on both cylinders (on a cold motor... I didn't bother to warm it up)....... the plugs looked a little rich...but I'll do a more thorough test later.... what seemed funny to me is that even with the throttle wide open it took 8-10 kicks to hit 170psi (any kicks after that yielded no increase).... like there might be an intake/exhaust restriction Quote Link to comment Share on other sites More sharing options...
Pasi S. Posted June 27, 2011 Report Share Posted June 27, 2011 I´m not an expert or anything, but in my opinion you may be rich on your main jets. If your mains are too big your motor will not rev enough in top end. In my motor there was a huge difference between 2 size in mains. The difference was like running hard and then after ripping like hell and lifting the front end in 4.th gear. ...I don´t know but if I were you I would try smaller mains and see how it will run. If your motor gets too much fuel and can´t rev up top, you get the feeling to go upper gear too fast and that makes you slow. (just my feelings) -Pasi S. Quote Link to comment Share on other sites More sharing options...
americanmusc1e Posted June 28, 2011 Author Report Share Posted June 28, 2011 I´m not an expert or anything, but in my opinion you may be rich on your main jets. If your mains are too big your motor will not rev enough in top end. In my motor there was a huge difference between 2 size in mains. The difference was like running hard and then after ripping like hell and lifting the front end in 4.th gear. ...I don´t know but if I were you I would try smaller mains and see how it will run. If your motor gets too much fuel and can´t rev up top, you get the feeling to go upper gear too fast and that makes you slow. (just my feelings) -Pasi S. that makes good sense...... I'm going after jetting tomorrow..... I have a set of 340 mains I might try..... I guess I'll have to order some more jets.... because the next size down I have is 300 Quote Link to comment Share on other sites More sharing options...
06specialedition Posted June 28, 2011 Report Share Posted June 28, 2011 Are you running pump gas or race fuel? At 170 compression I would be running race fuel.......just my opinion tho. Quote Link to comment Share on other sites More sharing options...
americanmusc1e Posted June 29, 2011 Author Report Share Posted June 29, 2011 I usually run 100LL avgas.... but my current tank is from a 5 gal can containing: 20oz Yamalube 3gal VP racing C12 (10.60 a gallon ) 2gal Shell 93 Octane Now I'm not sure I need smaller jets..... I might want to go bigger..... I warmed the motor up..... put new plugs in..... made one full throttle pass..... pulled the clutch.... shut it down..... and here are the results Quote Link to comment Share on other sites More sharing options...
darederek Posted June 30, 2011 Report Share Posted June 30, 2011 you have to chop the threads off with a hack saw or use a flashlight and magnifying glass to read the smoke ring to do a proper plug chop Quote Link to comment Share on other sites More sharing options...
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