dajogejr

I think you answered your own question... Lower the compression or buy C12. The 100octane AV gas is rated at is NOT the same octane regular fuel is rated at. I think 100AV gas on the same scale as car gas is only low to mid 90s. They don't use Research/motor octane numbers on average.

Beat me to it .... I run B9ES in my bike because I run a Nology Coil and wire setup. The wires have resistors built in and Nology recommends non-resistor plugs with their hot wire setup. I run a stock CDI and Stock Stator...too. Unless you're running something fancy, BR or B8ES will work just fine...gapped at .028 to .030

They cut 1-6 overrides now. They will never be dunable, and they will always be 100% tempermental. EVERY single one of them out now you MUST be 100% stopped before even thinking of downshifting. They will grenade if you are still moving and downshifting. Even .005 MPH. No BS. There simply is not enough room in the case or on the trans shaft to make a full 6 speed dunable override. Period. The cost it would take to have Mattoon make a set of cases and someone like Robinson to make the gears would be so exhorbant...it wouldn't be worth it, especially if you factor in most racing is done in 300ft or 660 feet. Any 300 foot rider only needs 2-5. However, if you ever go to the dunes, ride the ice or hit the pavement....especially on smaller motors you really need 1st gear. Launching in 2nd on a smaller motor with tall 1/8 or 1/4 mile gearing is very, VERY tough to do. That being said...I have a 1-5N down dunable that after 3 years of abuse still looks and shifts like new. By abuse I mean a LOT of passes down the track.

Only reason for a set of these is a Robinson billet trans. They eat shift forks like a fat kid on a cupcake. Otherwise... If you're bending/breaking forks on an override with a reasonable motor (not some 800 cc triple motor, etc.) you either have your override cut improperly or you are not using it properly (Backloading, etc.). okbeast is on to something, I'm with him. If you're bending forks because your override is cut for crap or you're not using it properly, what breaks next?

I would love to know how much money they lost with the "gift" processing....

Second... You shouldn't have to gap your plugs at .022 for gas. The only way you should have to gap them that small is if the ignition is failing, or if you have too much compression. Back to the domes. Check 'em out AND get a cranking compression reading...sounds like your problem lies there. If your domes check out and you still have to gap them at .022...try race fuel as said.

That is the funniest thing you've ever written...I had to laugh at that one. Plugs back out for two reasons. Deto or Fubar threads. And as said, they don't have to get hot to deto. What is your squish band and thickness at first off. I saw that was already asked but never answered. This could be as simple as the wrong domes. If that's the case, no amount of timing is going to help you. Since it's together, you can't measure the UCCR (Uncorrected compression ratio) but you can get the cranking compression. Measure that as well. If the squish is ok, then look to an air leak/and or fuel issue. I know you said you don't want to run race fuel...but I can promise finding 5 gallons of race fuel to test out vs. buying a new top end or more is cheaper in the long run. Try good race fuel and eliminate if AV Gas is the issue. I don't think AV Gas is hurting you....but when you have an issue like deto you cover all your bases, even the ones you're pretty positive aren't the problem.

He's either full of shit or not telling you the whole story. No stock port, stock stroke banshee motor with stock carbs that is running mid 4's on gas. Unless the bike weighs 100 lbs and so does the rider.... By no means am I saying that the Dynoport pipe is garbage, it's a good pipe...for the right application. If Kennedy is only worried about Peak HP on the dyno, he's wasting his time on a 2 into 1 pipe. A pair of Shearers will make more peak HP. I think he's looking for peak HP for any particular setup, which is what you shoot for in conjunction with a good, manageable torque curve. Shearer pipes make great peak power, there is no doubt there...but you don't see guys running around tight trails with them....

Interesting... Obviously this is going to fare better than a pair of his drag type pipes for overall riding and duning. I'm interested to see how it compares to other trail/dune oriented pipes that are duals (T5, Trinity, etc.) Interesting to know how it'll work against different pipes, port layouts, etc...as Snop Said. Since it's an inframe pipe...you probably won't have to worry about the welds cracking....

Here's my deal...yes, it has a TZ...and yes it has a TON of passes on it. But when it blew up, a buddy of mine was riding it (125lbs) and it was geared for me. He was probably tapped out with 40 to 50 feet to go at the track, and it's possible holding it to the wall that long caused it to fail...I'm honestly not sure. Either way, because I actually had a TZ fail I'm going to get straight cuts eventually...but not right now.

Port timings are a good place to start. The guys that make good power figure out the shape/angle and how to get the charge in/out more efficiently with the same numbers as others... That's the secret...and no one will tell you how/what they do. I certainly commend you for wanting to try this on your own...on the other side of the coin none of the best builders in the country ever picked up a set of cylinders and hit the nail on the head the first time. They got better, and better.... Good luck...let us know how it turns out.

I've been keeping my eye on that as well... I gotta get a new set of slugs for my motor this year, hopefully it's not the case. With the state of the economy, it wouldn't surprise me although I would be dissapointed.

That's how we roll in MI... Nice help out PapaSmurf!

Every cool head I've used and or had have leaked (including a stocker I had cut and Oringed for a cub motor) leaked out of one or more of the center 4 bolts. DLNOSS is dead on with new washers, acorn nuts and a dab of RTV on the acorn nut threads. Water seeps up the stud...and acorn nuts with RTV give it nowhere to go. They are metric, I know any Lowes, HomeDepot, Aco, Ace....they all carry them. If you're in the sticks, you might have to hit a metric supply store.

Yep...and it already shipped out TNT...as promised. Cody...backloading occasionally it'll be fine. But the failures I've seen are from guys that flat out told me they wound it out and just backloaded the hell out of it... You can tell by the wear what happened if there's a failure... Now I'm sure if you had a 120HP bike and backloaded the hell out of it it'd be failing a little earlier, but then again...someone once told me cubs aren't trail friendly either...LOL.

That's a pretty awesome deal Brandon... Let me know how it works out...fo sho.

Yep...as I can afford them. Nice thing is the whole thing doesn't have to come apart to put 'em on... After 4 years my Magnum basket from Jeff still looks great as well. A little discoloring where the plates rub on the ears...but that's to be expected. A year on my 4 mil cub and 3 years on my 10 mil...and my motor has a LOT of passes on it!

After destroying a TZ bearing on the PTO side of a crank (after 3 years) I'm going to pick up straight cuts when money can afford it. Do you need it? No...as others have said. It is good insurance....

Jeff...I want royalties for using Rich's cover for your advertisement....LOL Seriously, I tried...note, tried...to polish my cylinder. Without the right tools, know how and patience...it's pointless. However, done right it sure looks purdy. That, and it's just a dirty, dirty job period....

If they are factory A Arms (big, ugly, flat looking with a NON-replaceable ball joint), have someone make you aftermarket arms. As said, I wouldn't trust a 20 plus year old part. A properly built aftermarket J Arm is every bit as strong as an A Arm...and lighter.

Dinli, Kasea, Eton, Polaris...all the same.

J Arm are a favorite of the drag race crowd because they are in fact a few pounds (if that) lighter. J Arms from the yamaha factory are not as strong as the AArm bikes. However, several companies can make you aftermarket J arms that will do you just fine. The question is what do you plan on doing with your bike? Tim @ Stellar does some of the nicest AND most unique work I've ever seen... Keep in mind, if you are using factory J Arms they are at least 20 years old if not older...they were only made from 87-89.

I'm thinking if you're NOT kidding with that statement....credibility just went right out the window...

Depending on your skill...and how well the bike shifts as is...it could be only a tenth, it could be 3 tenths. But the key is you'll be able to shift it every time, not dip out of the power/torque curve...it will feel like 20 hp. 39s will work all day long on a healthy 4 mil.

Absolutely that's a good time. I had a 4 mil cub on gas with inframe Shearers, 35PWKs and a 6 over arm and 10 paddle haulers. Ran 4.7 to 4.9. No wheelie bar...stock style clutch (no lockup, Jeff's clutch kit) and no override. Problem was it wasn't consistent... Stock frame 100%... The problem was shifting, big time. And I'm also 250 lbs...