Forcefed

Yup, 352. Bore X Bore X Stroke X # of cyl`s X .7854 / 1000 = CC`s (in mm`s) 64.5 X 64.5 X 54 X 2 X .7854 / 1000 = 352 :biggrin:

... it wouldn't get above 60psi while kicking and lost all the comprssion as soon as I quit kicking.... quick question ... does your comp tester have a bleed off button ? .. and does it have an o-ring to seal at the threads ? Most comp testers have a schrader valve installed in them so that the gauge needle holds the highest reading - even after you quit kicking.... the only way to bleed it off would be to push the button. Could it be that you had a leak in the seal of the tester or a bad/stuck valve in the tester ? I`ve seen it happen many times...

Thats right, when running a 2-stroke engine will yield MUCH higher compression (dynamic) vs. that of which you get while only running the engine over at a couple hundred rpm`s with your foot (static). One of the major reasons, is the charging effect of the pipe.

Couldn`t agree more, & i was thinking about his porting along with the stroke. I just want to go on record that using static psi readings for judging octane requirements is NOT a good idea, but, if you want to try then I agree that for pump gas you are probably a little on the high side. I see in your signature that your cylinders have been ported - dune port right? ...the first thing most porters will do to a stock banshee cylinder is raise the exhaust port a bit. It may only be 1mm or so... Now with that in mind, trying to compare your compression readings with the "industry standard" of 150psi for a banshee with a stock heigth exhaust port - you will see how things can get a little fuzzy. 160 on a ported cylinder could very well be 175 on a stock one. You might drop the comp or run the C-12 like the previous owner did.

.... there might be a bit of a conflict of interest with that last idea, whitey. lol Anybody here around back in like `99 for the i-x banshee hq days ?

That is awefully nice of you sir.

Without my GRR pipes .... I couldn`t have set the National 350cc Record in `04 ! ... however, only to have the record then removed from me by, what else other than ........... than ......... another GRR engine using GRR exhaust ! Hell Yeah !

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Thanks....wonder what kind of #`s the bike was puttin down when it was being sprayed this summer ? ....not that #`s really matter at all anyways.....

It IS absolutely possible and has allready been done....many moons ago...... 89 RWHP and 49.6 ft/lbs Torque 350 - Stock cylinders - on Gas - 54mm crank - 4.1`s in 300ft with 180lb rider - stock chassis.

LOl...I thought someone was addressing the FAST bikes out there??? LOL LOL...You come off like youare a baller.....LOL Actually....you would be surprised what would happen if you put the chassis before the motor and the rider/tuner on top of both ! Nice bikes for real though.....

Right on...Ben is on the money. The reason it starts good cold and has a tendancy to foul a plug on the bottom end (pilot circuit) when warm is due to the fact that a motor has a tendancy to run a little richer once there is a certain amount of "heat soak" in the metal. Try turning your pilot adjustment screws in the "lean" direction about 1/2-1 full turn....all will then be well, and you should not have to worry about fouling another plug if you spend much time on the pilot circuit.

The preprogrammed curves that come in the Dyna, IF you buy it without some "Hotrod Shop" using their own curves is like this: Between 7K and 10K there is LESS than 1.25 degress seperating all off the curves. So, top-end on your bikes is nearly the same no-matter what curve the selector box is on. Now, between 3.6K and 6.5K is where all the change in the curves happens...primarily altering the midrange. For the question above--> @ 8K the Dyna curves go from 1.8 degrees advanced at the minimun to 2.4 advanced at the maximum....or roughly 2 degrees across the board. WEEEEELLLL......it is the sh*t , yes! But the relationship between timing advance and high RPM`s is not always so cut and dry. Our motors "prefer" to have the timing (heat) pulled AWY from it at the Upper RPM`s. This is when the engine starts to become efficient due to the port timing harmonizing with the exhaust...once you are "on the pipe" the need to start the flame front so soon (timing advance) is no longer needed. Be careful advancing timing soley in the higher R`s, there are gremlins there.

Results?!? How about the endless adjustability to allow EVERY different engine/porting/riding combination to be used at its full potential EVERYWHERE in the RPM range...something the "key and plate" could only dream of. I program my own curves as well as the curves for alot of my competitors/friends. Lets say your running a very high compression ratio...17.5:1 and it comes out of the hole and midrange VERY nicely...but...you want to spray 40hp worth of N20 at it. Conventional wisdom would tell you that you need to lower the compression ratio in order to use the nitrous without grenading your motor. Well, with the Dyna you could keep a moderate amouont of timing in the low-mid RPM`s and then pull the timing away in the upper spectrum. Just one of many different examples of how the Dyna is superior to ANY other ignition system on the market. In one word...FLEXIBILITY....throughout the RPM range in a NON-LINEAR fashion. Remember folks....timing....is EVERYTHING. p.s oh, and you can run the "key or plate" in conjunction with the Dyna (although not sure why you would want to) all you have to do is subtract the amount of timing from your curves programmed into the Dyna by the same amount you advance it elsewhere. All the preprogrammed curves in the Dyna end in the upper RPM`s (around 10K) the same...about 3 degrees advanced. If you say DID NOT own the programming software and needed more timing, you could adjust the plate incrementally to gain what you needed. Say you drag race on Alky and need like +7 degrees of timing. Well since the Dyna is near 3* advanced you could put the plate at +4 to achieve the results. Although please proceed with caution any time you advance the timing on your bike....you ARE creating HEAT within the combustion chamber. This can be beneficial if you need it and destructive if you don`t. It is up to you and your specific set-up to determine JUST how much timing you need.

If you are seeing "black/burnt" spots on the surface of the cylinders when you do a head gasket replacement....then you can pretty much bet the gasket didn`t seal. You had the head checked...what about the deck surface? What about jetting or minor detonation? You mentioned you had the head machined...how much was taken off? What was the comp diff before and after? Did the machinist rechamber the head after removing the material? What was/is the squish tolerance since the machine work? Many people think decking the Banshee head is a cheap and easy mod....well it is. But if you don`t take the above mentioned factors into consideration, you can end up with a real headache in the long run. The squish clearence, SAR (squish area ratio -->to bore size), MSV (maximum squish velocity) UCCR and CCR ALL need to be in check with each other to avoid potential issues. If the guy is just a machinist, and not a 2-stroke builder....he mat not know any better. All he knows is that the customer wants .030 off the head...bam...done. What about border line octane requirements.......jetting issues....too much timing for the increase in Comp, SAR, and MSV......take a good hard look at things man, and ask some questions in reference to the head work. My .02

What was that bolt used for? Tap it. Can you enlarge the hole and use the next size bigger hardware? It`ll be O.K. man....deep breaths!

Very nice reply J.J. Wish they all could be as informative as that one! Kiwibanshee....J.J. is right on the money...been there and done that a couple of times. Take your time with the bearing and the seal in the cases though...can be a little nerve racking sometimes.

ummm maybe...but if it was an ignition problem wouldn`t the "lean" plug actually be dripping wet and fouled from the ignition not lighting the fuel off? Honestly man...I think you are on the right track with the airleak scenario...although since you have eliminated many possibilities with the replacement parts for the intake tract, you may need to take a step further. DO a compression check (by the book) and then have a leak down test performed...you may have very well had a crank seal go out on you (typical) and is drawing air in......maybe something to do with the head as well. A coolant leak WILL show similiar signs of a lean condition due to the superheated steam cleaning the fuel/oil off of the plugs (as well as the cylinder walls/crank ) If you confident there is nothing in the intake tract....and the ignition is not your problem ....its them time to dig a little deeper.

Well....just got back from the ATV Bluegrass Nationals and................ Turned a 3.888 @ 84.17 Mph backed up with a 3.923 @ 83.15 mph on a Grand River Racing Cannon! My boys The Mauk Brothers ran a 3.876 and a 3.906 ALSO on a GRR machine. ROCK ON !

Yeah...we run alot of 200ft as well as 300ft. My times in 200ft are 3.0 - 3.1`s.

Well...sprayed a small shot at my ride for the past few weekends. Managed to turn quite a few mid 4.0`s! Going to turn the wick up a little higher and see how deep into the 3`s it`ll go...

4.27 on gas - 364cc - stock frame Going to spray the crap out of it this weekend and see what it`ll do.

AlcoholBanshee...KICK ASS! Josh A. It has some fresh spark plus, and oil change, and a new gas cap vent....other than that...its a GRAND RIVER RACING MACHINE!

Can`t wait to see the GRR Crew this weekend! I have run 4.2`s-4.3`s on studs this year and 4.3`s-4.4`s on Pro-Wedges (1`s or 2`s) Gas - 350 - Stock Frame