mopar1rules

RNBRAD-what petals did you change to? NYUK-what exactly did you trim back? Snopczynski-i cleaned up the intake ports a little. i put the "knife" edge to the center divider. could i still notch out a little chunk of the stopper, to keep it nice and open to the little port on top of the intakes? i'm trying to get the pics to post, but they won't. 1) go to www.totallyamaha.com 2) click on "technical pages" on left side of page 3) click on "snowmobile tech" 4) click on "engine" 5) click on "reed stopper notch"

you only have to rejet every 2000-3000 feet of elevation change, not every 300-400 feet.

ahhhh, i see. thanks.

ok, my shee had some boyessen dual stage petals on w/o reed stoppers and just a little flat plate of metal, that was bolted to the reed petals and cages (i think it would be a reed petal stiffener...not sure). the petals were pretty much junk, so i installed some new carbon techs. i also installed some reed stoppers on my stock shee cages, w/some fresh carbon tech petals and when i installed the cage assembly into the cylinder, i noticed that the top reed stopper blocks off almost half the flow to the little port on top of the 2 large intake ports. i know on the sx700 yamaha snowmobiles, they have this same issue, and guys will either use reed spacers or notch the top reed stopper, so it doesn't block off the flow like this. so here's what i'm wondering....what will be my best thing to do? should i just remove the reed stoppers period, should i just notch the top reed stopper, or should i get some reed spacers?

i was kinda worried about that.....oh well. i'll just order some new ones out of marshall or western power sports. hey snoop, how bout those carbs?

once you hit 150psi for compression, i like to have a 50/50 mix of race fuel to 93 octane, to be safe also.

did you try my jetting recommendations? if so, how did it work?

shaving the intakes to match? what do you mean? can you elaborate on this for me please? i never heard of this.

OK, THANKS

well, this is good to know. the wheels in my head were spinning this morning, and i just thought of posting this, to get all of your guys's thoughts:)

thanks guys. thats what i was thinking...2 per. one top, one bottom. just double checking.

is there an advantage to taper boring carbs versus straight boring? i was thinking with taper boring, you would increase the velocity of the air...right? just like the venturis on the stock carbs. they start big and then taper down to 26mm. shouldn't it speed up the air travel if i taper the bore 2 mm? start at 28mm on the intake side and taper it down to 26mm on the engine side? or should i just bore it to 27.5mm-28mm? looking for a cheap alternative to more power for now, until i can afford the 28mm flatslide tm's.

how many reed stoppers is the banshee suppose to have stock? is it 2 per reed valve assembly? mine doesn't have any. i'm assuming the kid i bought the shee from, took 'em off when he installed the boyessen dual stage reed petals. they are shot now, and i ordered carbon techs, but i think i need to order some reed stoppers too. just need to know how many. there is a set of stock reed valve assemblies on ebay right now, and its showing only 1 reed stopper per reed valve assembly. wtf?

yeah, just throw in pilots, that are 1 size larger than what you are currently using and you should be spot on.

what should the piston/cylinder clearance be on my bored .040" over cylinders? like .004" to .006"? i tore my top end down tonight, to check to see if my ports were chamfered after the .040" over bore, and sure enough they weren't. i also noticed some slight scratches in the cylinder wall, and on the intake side of the pistons. you can't catch your finger nails on them, so they are mainly cosmetic. it seemed to me like the piston was expanding and making contact with the cylinder wall. i measured the bore and it was only like .002"-.003" over the pistons 2.565" measured size. i don't know if the lubrication was wiped a little bit off the pistons skirt, from the ports not being chamfered. the only good thing i seen was that there was no blow by on the pistons. the rings really seated with the amsoil dominator that i use. oh yeah, these are pro x pistons if you guys want to know. i don't know how many hours are on this engine, but the reason i tore the top end down, was cause another fellow on this site had his engine go down, and his ports weren't chamfered, and that got me thinking about my top end. i didn't recall seeing any chamfering on the ports. good thing i tore the top end down.

more compression gives you more low end torque. to be safe on 93 pump gas, i wouldn't run a dome smaller than 20cc. one of my buddies has 19cc domes on his pro design, but he runs a 50/50 mix of race gas and 93 octane to be safe. i hear from more people that the noss machine head is better, but i think some of it boils down to personal preference. the smaller domes would be more ideal for high altitude situations, and the larger domes for low altitudes.

you say everything is stock. don't you have k&n pod filters? if you have them and everything else is stock, you will be needing to run like 240 mains and 27.5 pilots and needle stock.

if i was you i would put the needle clip in the middle slot. i would go to 50 pilots too and try that. if the low end is doggy, then go back to 45's or 47.5's. i would also try like 155's and see how it likes it.

the water pump impeller that your buddy is talking about is probably the vitos. it is suppose to pump coolant faster i believe.

yep, if you are trying to run stock jetting, you are too lean. you will need to have like 250-260 mains and might need to bump your pilots up to 27.5. i would think your 25 pilots are just fine. leave the stock needles in w/clip in stock position. snyc the carbs and report back. you may have to turn your idle screws in.

your jetting is too lean!! you will be needing to run like 240 mains and 27.5 pilots. leave the needle alone. what is your elevation and outdoor temp?

are your carbs clean/sync? what are all your mods, elevation, outdoor temp?

i would run the brand of silencer with the brand of pipe that i have. ex. fmf fatties into fmf power core 2 silencers NOT fmf fatties into pro circuit silencers just my .02

and what cc domes are you using now? so your main jets right now are 200? what is your current jetting....pilots, main, needles, needle clip postition, pilot screws turns?

i see in the last pic that you posted, that who ever ported your cylinders, didn't add the 2 boost ports. i would think that any reputable shop, that does great port work, would know enough to add those 2 ports. i talked to a guy that built numerous banshees and said that the 2 added boost ports are what really wake it up when porting. i would say to start looking elsewhere from now on in your engine repairs/mods.