4stroker

hey thanks for that man, i had a quick look on their website but couldnt find it, so ill try ringing them. thanks, mark

all good ideas, thanks guys! im not making my own domes to save money, im making them myself so i know that they are set up exaxtly how i want them for my motor. eg i have very specific ideas on squish height, angle and band width, as well as a specific blending radius, not to mention a true hemispherical combustion chamber, which has to be a certain volume to get the compression ratio im aiming for... ive designed a set before for a friends 500cc TREX, but i just needed some ideas on the raised dome of the 795 piston, as the trex has a relatively flat top piston. ( i know how to design the dome to accept the piston, just needed an accurae way of measuring it) sure i could get noss or any other engine builder to make my domes, but why would i get all my specs together, send em off to them and get them to make it, when i can do it all here right in my own home town? also, believe me, it is alot easier to spend half an hour drawing my domes in autocad and having them spat out of a cnc lathe, than it is to modify some generic pro design or noss domes! thanks, mark

which carbs should i get for my 4mm rz motor to run it on alcohol? are mikuni tmx the ones to get, do they have the power jets? which carbs do FTZ use for their alcohol carb package? i noticed that FTZ gas carbs are $440 a set, and FTZ alcohol carbs are like $660, why are they so much dearer, what do they do to them? i would have thought that you could just get the regular carbs, and change the dump tube, needle and jets to suit alcohol? oh yeah im also lookin at bigger bowls and a pulse pump. any info greatly appreciated! thanks, mark

pretty cool test you did, one day im gonna book the dyno here for the day and try a bunch of my stuff on it. if it were me though, i would keep the dual mikuni's on. the single carb makes 1 or 2 horsepower more before 6500, but takes away 4 hp after that. also, you are still getting that 9 hp jump from approx 6500 to 6900... 9hp in 400 rpm!!! thats what makes your wheels spin lol also, both setups produce the same flat torque curve from about 6900 onwards, but the mikunis do it with 2 ft lb more the whole way... and how do you jet a single carb twin cylinder, if both cylinders dont run exactly the same? i know on my quad and lots of my friends quads that one cylinder always runs leaner or richer than the other (especially when ported) for example i run a 187 main jet in the right carb and a 185 in the left because when doing plug chops the right sparkplug always came out with a bit less colour on it than the left... i would like the easy throttle pull of the single carb though!

thanks for the reply firehead, however i have no idea what your talking about lol... in what sort of workshop/lab would i find an optical comparator? and what exactly is a CMM machine? im gonna have to learn how to do this myself, or find someone to do it cheap, because i plan on keeping this motor for a long time so i will prob have to modify the domes every time i bore it... my grandfather used to work in the local foundry, maybe the pattern makers there could help me? or the guy with the cnc machinery, i hadnt thought of asking him for help measuring the piston... thanks again, mark

hey guys, ive got an rz motor that im dropping a 4mm stroker crank into. i dont wanna run a spacer under the barrels so im porting them to suit the stroker and gonna run a pro design head with my own design domes. (local machine shop has cnc lathes and milling machines, and ive got a hunk of 6061 aluminium ) what is the most accurate way to measure the raised dome of the piston, so that i can design the proper squish angle relative to the piston? are there any diagrams or anything floating around that show the radius and height of the dome? im using 66mm wiseco 795 pistons, so when maching the 2mm step into the domes, im going to make it exactly 66mm as well. am i going to have to increase that diameter when i go to the next oversize piston? (ill prolly have to make new domes anyway when that happens, as ill have to use blaster pistons for the next oversize) any help would be greatly appreciated! thanks, mark

i have seen 11000 rpm on a banshee with nothing more than DMC alien pipes and a K&N filter is my tacho wrong?

Hey there. I am trying to find out if a 66mm Wiseco blaster piston is the exact same piston as a 66mm Wiseco 795 series banshee long rod piston. reason i want to know is, im building a long rod motor and the jugs are on 66mm bore. im using 66mm 795 pistons but thats the biggest 795 piston wiseco make. So if i ever need to rebore it will i be able to use 66.25 and 66.5 blaster pistons? (assuming my cyls can be bored 100 thou over) thanks, mark

lol, i totally and utterly disagree with this statement....

like the title says looking for a good brand swingarm with carrier that is NOT BENT! carrier has to suit oem banshee axle and brakes/sprockets thanks, mark

still available? send pics to [email protected]

Boruts CDI comes with 5 curves as does his PPV controller. when you buy the stuff off him he gives you the graphs too of what they all are

went back through my calculations and realised id posted in here too early lol... i have managed to keep the corrected compression ratio the same (6.349:1) but when i checked my uncorrected ratios i had forgotten to take into account the squish volume for both scenarios.... so, in actual fact, the uncorrected compression before was 11.188:1, and now with the smaller domes it is approx. 11.8:1 (because even though the dome is smaller, i have opened the squish up 10 thou) so i am confident that this will work no worries, as UCCR hasnt even risen a whole point, and CCR is the same as before! thanks anyway guys!

thanks for the replies guys. im pretty sure i have the design of the new dome spot on. it has a 10.6mm wide squish band (72.42mm bore = 50% squish ratio) and a squish height of 45 thou. i gave it a 1mm blending radius and a true hemispherical combustion chamber. the squish angle is 3 degrees relative to the piston. the trex piston is "flat top" however it does have a slight 2 degree rise from the edge to the centre. the old dome had 21cc engraved on it. i measured it roughly with water but need to check it more acurately (got a burette ordered) before we machine anything. i used some special formulas such as "volume of a cone frustrum" and "spherical portion" to calculate the dimensions of the new dome. the new dome should measure out at approx 18.5cc. oh yeah its a 72mm bore, 7mm stroker trex!

ok im lookin for some of the really knowledgeable engine guys on here to help me out with this! ive read Graham Bells book and a whole bunch of stuff on the net, and have designed a dome for a buddy's trex motor. (im a cad technician) we put a spacer plate under the barrels to lift the port timings and have drawn a new dome to compensate for the extra deck height, coz we are unsure if he will like the new power delivery, we dont want to deck the barrels so we can put it back to how it was if need be. ANYWAY!! before the mods, uncorrected compression was approx 12.9:1. corrected compression was approx. 6.4:1. the old dome measured at 21cc. now with the spacer plate, we have less effective stroke, so to keep the corrected compression at 6.4:1, i have designed the dome to only be approx. 18.5cc. however with this dome, uncorrected compression is around 14.5:1. we dont wanna run anything higher than 100 octane, which is what we were running before. i am not sure which figures i should pay attention to, the corrected or uncorrected comp ratios? i guess what we will do is get a whole bunch of domes made up in different sizes and do some testing, but it would be really cool if we got it right the first time! thanks, mark

just going off the pictures i can see on ebay, it doesnt look like the aftermarket bearings (max load, wiseco..) have the little pips on them to stop them spinning in the case. is this right? if so, is it a problem? when people say they put tz250 bearings in, are they a genuine yamaha part? thanks again, mark

hey guys im chasin a hot rods +4mm stroke, long rod crank. dont care what condition it is in as long as it is rebuildable and the price is right... thanks, mark.

thanks for the replies guys where is the best place to get tz bearings from, i wanna put em all the way across... thanks, mark

hey guys a local crank guy is rebuilding my crank for me and i want to put the best bearings possible on it i know you can get a TZ bearing for the PTO side, what about the other side? also what about the centre bearings? and should i put wiseco hot rods on it or oem? or TZ250 rods? thanks, mark.

unlucky man, i had to split my cases two weekends in a row due to the clutch rod welding to the actuator its easy though i had never done it before but i tore it down on sunday night and had it running again monday night (had to go to work on monday!) get a clymers manual, a rubber mallet, some new crank seals and some 3 bond and youll be set!

i think you get that washer with your axle when you buy it and you use it if installing that axle into a blaster dont take my word for it though!!

even more reason to port em yourself!

dont send em out man have a go your self and learn something buy a few books and read everything you can on the internet and start cutting! take the port out wider and oval shape the roof of it with the centre of the port about 2mm higher than it is now. the shape of the port is important to get your rings to last but unless you go berko on it you should be right make sure you end up with a nice little chamfer on the port so it dont catch on the rings and polish the whole exhaust outlet in my opinion if you take your time and be smart about it you shouldnt go too wrong but even if you do stuff up who cares whats a stock set of cyls worth these days $200??

is that an axle nut he used??? a friend just bought a banshee with this exact "mod" lol. he went and bought a whole new shaft from yamaha for only $120. (aus) the same banshee also had the splines on the axle and sprocket hub stripped, and it had a dirty big grub screw through them both to "fix" it he knew all this when buying it though, it was a cheap banshee!

if you buy a zeeltronic cdi and pv controller you can use banshee stator and flywheel, otherwise the only thing banshee you can use with rz stuff is the coil. you could set the valves manually to where stock banshee ports are or even maybe a touch higher and it would work good (better than standard banshee, depending on what model rz barrels you have) you will have to loctite or silicon etc them in place though ( hard to explain unless you have torn the system apart before) scour ebay for the parts they come up failry often