kingsley

DDU sounds a bit dirty to me. Il have a chat with him, he is about 2500Miles from me but might have some usefull contacts. In the mean time i have been able to speak to a workshop in Melbourne who knows these bores and is confident to weld the damaged section, replate it and supply a piston for around the $500AU mark. Seems like a no brainer to me. One last question...... Can someone recomend a supplier who can supply one 22cc coolhead dome to suit the blaster piston? The other side is still fine. Thanks guys!

Hi everyone, I managed to bust a ring on my left piston and its put nice groove down the side of the Serval bore. The right side is still like new and the bores have done very little work. Can i just repair the bore and recoat back to standard (421cc) on that side or would i be better off boring out the damage on both sides and go over size. At this stage im up for atleast one piston and dome. I have a 7mm crank still in the box so am i better off just buying a new 7mm Serval with pistons and domes? P.s im in Australia so any repair would have to include shipping back to the states.

Is there enough meat in the water gallorys to drill and tap a temp sender or even case a spot there for future barrels? IS this a good place to put it apart from the top hose with a joiner fitting?

Hi Calvin. I believe the question i have asked here is directly related to the time that you spent on Friday for a 7mm crank in a 4mm serval. My reason for asking the question was to gain more of an understanding of the outcome of this combination. I am reasonably new to the performance workings of a 2 stroke. After looking at your PDF file. I notice the exhaust timing is practically exactly the same as the 4mm with 186.3 but the main transfer (inlet ports?) open fully at 3deg later. Again not knowing much on this subject. How different will the result be? My guess is that the torque will be slightly later in the RPM. Is the difference in torque delivery mostly noticed when the inlets are adjusted or when the exhaust is adjusted? Obviously this combination will be different to a 4mm set up as the torque and HP will change again because of the 7mm stroke and i may not even notice a difference or see more. At the end of the day, i came from a poor designed 66.5mm bore with a 4mm crank and running 22cc banshee domes with blaster pistons. The combination was all wrong but i was very happy with performance i had.

If you were to take a 4mm serval,run the 7mm crank, no base gasket and cut domes, Would that be what you would work with? If im right, does this efectivly raise the ports on the serval and increase the RPM level when the torque comes in or does it over come the issue with the extra 3mm on the stroke? Reason for asking is that i will be running that combination with 34mm carbys, +4timing and FMF fattys with 22cc domes. Just awaiting the cut domes.

Are the ones that M&M sell pretty good, i see they have a SS shaft? Are they a strait fit up?

Will the cooling system have to be upgraded when building this engine? e.g water pump and radiator?

Currently i have both air cleaner styles and im running the pods on a pair of 34m carbies. I dont like the idea of the pods sitting out in the open for fear of water, extra exposure to dirt and damage. What has the better air flow? Pods or the single K&N in the air box? I imagine the pods do but will i notice it verses single K&N? Dune/trail use.

Thanks for that. I bought it through Andy at M&M. I only have FMF fattys to start with.

Ive ordered a Serval engine package and it includes cool head domes. Ive also added an adjustable timing plate to it. This will be run with the 4mm crank. When making the order, i stated my fuel will be 93mon (98RON AUS) and run at close to sea level. Ive worked out that id should get 21cc domes thrown my way. Would my thoughts be fairly close or what would i expect to see? Kingsley

How well will the FMF Fattys work on this motor? Dirtydownunder.... How much tax did they slug you?

Its claimed that the top of the casings dont have to be machined to fit the big bores in. I was unaware that i would be building a drag engine. If i understand correctly, a drag ported motor will not be suited for dune or track work, since the power will be made mostly in the higher rev range and have less power/torgue down low in the parts where id need torque? As far as having the upgrade the pipes, im open to do that to get the performance from it. I like the idea of the big cubes to increase to lower torque... Would i achieve that buy having a 472cc with no port work done or light work? Or... Would the 421 be suited better, with or with out port work?

Im looking at fitting 472cc cub cylinders to my bike. Currently i have FMF Fattys. Do the pipes or "flange" go up in size when running the 472? or will my FMF pipes still fit? Theres only a couple hundred more dollars to buy the 472cc kit, compared to the 421cc kits. They are both a bolt on with my 4mm hotrod crank and rod and i can use my cool head still but with 69mm domes, that ive been told. I know il have noticeable more power with the 472cc but will i create a list of problems with the 472 compared to the 421, apart from a larger radiator and pump? I have 34mm carbs also.

Im looking for some banshee domes to suit 66.5mm bores with blaster pistons. Im running a 4mm crank so a 2mm recessed set would be nice but not important. 22cc would be nice to sute the 98octain fuel (93US) Cheers Kingsley

Over here in Australia im limited to what i can find for go fast bits for my Banshee. Currently im running a Hotrods 4mm crank and rod with blaster 66.5mm pistons, coolhead, 34mm carbs and FMF fattys. My water jackets are no longer big enough to handle the heat soak from the bigger bores and increased power. Im at the stage where i want to buy some bigger bores for it. Is there an off the shelf option that i can buy over the net? Id prefer something that i can simply bolt to my cases, still run my 34mm carbs, pipes and use the cool head. Il be using 98fuel (US93)and would like the domes to give the most for my fuel while at see level. Il still be running the 4mm crank. Currently i have 402cc and dont realy want to down size the bores as its not enough power at times already. A bore size starting at 68mm would be very nice if the rest of my motor can support that (carbs and pipes) Thanks in advance Kingsley

Hi. Just a quick one...whats the thickness of the factory 04 banshee radiator core? Im looking at a new one that is 40mm thick. Is this bigger or am i wasting my time? The bike gets a hard time on a salt lake and id like a bit of extra cooling capacity for the 402. Cheers

Running a K&N pod with a pre filter, lid on.

Im after a little help with jetting selection for my 04. Im running FMF fattys, stock carbs, K&N filter, 22cc coolhead, 66.5mm bore, 4mm stroker. 98octane 25:1 synthetic. Most of the running is on the dunes, close to sea level. Thanks in advance

Hello New to this forum Im having an issue with my gear box. The first sign was a broken bolt on the shfiter that locates the centering spring and acts as a limiting bolt to limit the travel of the shifter. I replaced the bolt with genuien yamaha replacment. That fixed the problem and the box worked very well for a few hours of riding. Until i could only select 2nd and 3rd. After pulling the side cover off again, i found no signs of breakage like before and was able to regain all gears with the use of the shifter while in the shed. I may of had the selector jump out of alingment. But The part im concerned about is the slop that i have only in first gear. With the side cover off, i can rotate the input shaft back and forth 1/4 of a turn before the slop is taken up but have minimal/aceptable back lash in the rest of the gears. Is this normal for 1st gear, it feels like way too much for my liking. Im getting the feeling that a tooth may have come off of the 1st gear and may have lodged it self in the seletor barrel, limiting the rotation of the barrel and being unable to select other gears. I also noticed a slight metalic flake present in the oil but looked to be aluminum. Many thanks for any help Kingsley