deckheight

Main problem is OEM flywheel bodies are stamped, not machined and factory balanced after attaching the hub. As soon as you put a tool bit to one it throws out the already marginal factory balance. That is pretty much what I do with them... Indicate on two axis in a 4-jaw chuck. Some are way off balance after machining, some not. I just use a set of balancing weys, if I did dynamic balancing I would expect even worse.

Get a decent caliper, establish an accurate exhaust port timing ATDC and bore diameter. Put the head back on, get a buret, dial indicator/spark plug fixture and establish an accurate trapped volume and proceed to the next level of tuning. If you are going to be modifying you own engines and want to do it correctly anyway...

Typical aftermarket dome bore diameter is 66mm. So you probably should be looking at big bore domes beyond that. Good cylinder porting will work with stock carbs, usually works even better with larger carbs as long as they are not too big. 30mm-33mm carbs seem to hold a tune real well. But some people like a little bigger or smaller... If you want low end response and easy tuning over a higher rpm motor, stick with smaller carb sizes. Nothing wrong with big bore cylinders, however, for the money, most people opt for a long rod +4mm crank instead of a big bore set-up. Don't discount stock stroke/small bore engines though, they can be made to run fairly strong also. A lot of high octane fuel can be bought for the price of either a stroker or big bore motor package. Lot of people running +4mm strokers/stock carbs and like it. See no reason why it wouldn't be a similar scenario with a big bore stock vs. bigger carbs.

I remove 249 grams and consider that the standard, fail safe recreation cut. 100 grams is not even worth bothering with IMHO. Tell the machinist to weigh it, should be something like 49.6oz. stock (1,389 grams). If so, turn the OD to 4.900", face .040", leaving a strong back in line with the trigger. That alone should get a little over 200 grams. Then I make a couple other cuts that are hard to explain here to get the other 49. AND MAKE SURE IT IS AT LEAST STATICALLY BALANCED! If it will not be rebalanced after cutting then you probably better stick with the 100 gram blue light special package deal or whatever...

The bust or "boost" port is the single one on the intake side. Or maybe I'm not understanding either...

Well... Sounds kinda like you got a pretty good feel for which way the wind blows over at Hotrods. Better to take the loss and move forward sometimes... Good luck

They do several things. Spacers set the reeds back farther from all the crank case turbulance which is mandatory in certain "case reed" applications. But not on Banshees which are "cylinder reeds". They also increase crankcase volume thus reducing crank case compression ratios which may or may not be helpfull depending... Pretty much useless on a Banshee IMHO.

It's all good... That's why :biggrin: My name is nobody around here too LOL! However, I do know more than enough about tuning 2-stroke engines to know when someone is blowing smoke up my ass in a post. Personally, I would consider using two of the three names you just mentioned in addition to the "Gentleman". Call around, there are a lot of good builders out there. Just be carefull! If something doesn't sound right ask some more questions here. Prime example of something not sounding right would be the subject at hand. "so minimal you wouldn't notice it"??? Personally I think 2mm each direction would be noticable

Doesn't hurt, doesn't help either...

That sucks! Not just the crank either, stator, coils... My guess would be a defective crank nose??? I'm sure things sometimes slip through quality control cracks... I would also think the flywheel would have to be so far out of balance for this to happen in such a short time frame that vibrations would have been very noticable. I have seen crank noses break off, but not on a Banshee, yet. And never that quick, yet. I would dought very seriously that anyone at Hotrods will admit responsability. Even so, someone over there should step up to the plate and make it right for you, IMPO anyway. If you want to send me the flywheel I'll check it FOC, assuming it's not destroyed also??? At least that way you can eliminate or confirm that possability. Good luck.

I am running 33mm PWK's, probably pushing 70hp at the crank in it's current tune. Stock petcock=no problemo... I think the problems begin with built alcohol motors

The gentleman just answered your question correctly... In adddition, from reading past posts, he obviously knows what he is doing... At least include him in the post as a possible... Jeeez! :biggrin:

Just to add to what has already been said... Maximum squish velocity or "MSV" is an indicator of combustion chamber turbulance and is measured in meters per second of travel.

Cool, thanks for the link. How do you like it compared to a motor driven tool? Does it have variable speed? And how is the torque at low speed if it does? edited for sphelling...

Lightened flywheel = Barely noticable, but it is noticable. Lost inertia is not even a concern. Cutting an OEM head for 92 or 93 Pump octane number fuel (PON) = Defenitely noticable. See if whoever cuts the flywheel will static balance it also and pay the x-tra $$$ to have the OEM head re-chambered while they are at it. You can't just face .030" off the head and call it good... You will end up with something like .028" squish clearance and your MSV will be through the roof, if the piston doesn't go through it first...

Snop, I am not familiar with that. Is it an air tool? Got a link to it maybe?

Not that I know of. I remember paying something like $225 for my first one a long time ago and around $350 for a reverse rotation handpiece 5 years ago maybe. I know I saw a bigger 90* handpiece in a catalog they sent. Pretty big bucks if memory serves, didn't pay much attention to it.

Speaking of kids... Did I ever mention that there will be 68lb. rider on mine?

Well... You been buying into the old "my bikes broke" song and dance pretty good so far :biggrin: I think i will stick with that one for a while longer before switching to something else??? Anyway, I just hate sitting there while someone else is signing autographs...

Looks like a good overall package. Good hard linear pull right to the top. Not too shabby of a max rpm for T-5's either... No really weird bumps or blips... What octane fuel is the top end set up for? Thanks for posting that :cool:

Looks like I have got everything. Thanks :biggrin:

Had to be Oregon didn't it LOL! Very interesting way of tuning a "hill shooter", IMHO anyway... There is really no reason to tune a motor that close to the edge for recreation type riding and I suspect there is probably more going on there than just jetting anyway. If it were just jetting or an air leak I would have expected to see the thing detonation seize before the piston vented. Besides all the usual stuff, might consider establishing an accurate CCR/fuel octane requirement, check crank phase as well as CDI function. Would defenitely consider backing off the ignition timing, possibly stagger main jetting and might even consider staggering the compression ratio, depending... Good luck

If your talking 92-93 octane type pump gas... 21cc easy. Might post over in the jetting forum, maybe someone with similar mods can help w/jetting?

Thanks for responding. Just bought a swinger yesterday... Still need the jarms though if your interested???

From what I have read, not a complete sham. The way I understand octane booster in a bottle is that a +2 to +3 octane increases are doable. Problem is that for about the same $$$ a person can buy a similar octane fuel to start with. At any rate, I personally would never use any of them as a substitute for a higher octane fuel, especially on a 2-stroke! But thats JMHO. There is no "ideal" "Banshee" ignition advance, too many variables. However, for a typical 350 running typical pump gas compression +4 is about what you want. Start changing parameters much beyond typical and it gets pretty interesting... I have never been to Glamis, so not much help there. Post you location and I am sure someone knows where to get good fuel. I always bring my own fuel from home. If I run out of gas I usually quit riding and start drinking I don't like buying gas from unfamiliar places and only very rarely will I use someones elses fuel. Again, JMHO for what it's worth...