J-Madd

That's a good point that I would have to agree with. I've beaten a few 10 mil Cubs on extended chassis's with my stock lightened chassis 4 mil; and it has only a cleanup port job; and will occasionally run 4.0s. If money is no object, I always think you should go way bigger/better when you upgrade ANYTHING (house, boat, truck, etc.)...just kind of skip the next stepping stone. If you run at a particular track, I would build a motor at the top of the CC range for a class if possible. I'm always stuck running a 392 Cub and 421 Cub in 0-550; and the 593 cheetah with the 0-650. Not that they aren't competetive in those classes, just that they are definately disadvantaged.

Sorry, I don't have a clue

The difference in the power of the Twister or DM compared to a Cub is because the bore is huge (72-78mm) on those, yielding much more ccs. I wouldn't base my decision to go with those based on reed cage design, but on whether I want a 465 cc (or whatever) or a ~ 600 cc motor; and what my chassis could handle....and what classes it would fit in at the track. .........And of course price. But that would be the last determining factor in drag racing :biggrin:

I even saw a RS that had to have the pickup coil wires reversed to fire. It was wired backwards from the factory. But...that is not the problem here. Just wanted to pass that on.

YOu could always buy the bigger cover and run the slingshot. That's what I did on my 421; and ground the cover on the 392. I like the slingshot vs the DD. I've ran both. The slingshot seems to lock up instantly, which is what I like; though some want it to slip a little at first.

It's common for it to be difficult to find neutral, and it not wanting to roll with the clutch pulled in, etc, but not to the extent that you described. Tighten the clutch cable. When to clutch is fried, it slips, not grabs...as mentioned.

YOu won't like the 1-4. Like Dave said..you have to gear it to launch in 1st so you don't run out of gear, and that just doesn't work very well.

It replaces the pressure plate.

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Your jetting is probably lean or you have detonation in the first 2 scenarios. On the third scenario, you compensated for the lean jetting by backing the timing down. Less timing generally requires less fuel. Give it more fuel (high octane) and try the first 2 again. jmo.

The part of the coil wire that goes on the spark plug.

That's what I was thinking.

Alright...I worked out the formula for my stock stroke Cub with the timing advanced 2mm and get 16.4*. This is less than the stock timing of 17*, therefore I need to advance it 8 or so more degrees to put it where it was with the stock cdi and timing plate at +8, correct? Or does the PVL ignition advance the timing?? Pretty sure it has a built in retard curve, not sure about the advance....I guess I'll check Penton's web site. Either way, the damn thing took a crap, I think. I was in the staging lane for test and tune running fine, then got to the front of the line and the right side started detonating, almost blowing the pipe off. Never got to run it. Gonna test the coils and get a better ground (remove powdercoat) and see if that fixes it.

Thanks all. But why does he list the formula as Cos instead of Cos^-1 in the book?? EDIT: Note that the stupid CPU calculator has a box to check to get an inverse function. Just figured that out, and that fixes everything in the calculation.

Regardless of the ignition system employed, the spark plug must fire at the correct time if good power is to be made and engine damage avoided. Some two-strokes are timed to spark at 2mm before TDC, others at anywhere from 0.4mm to 4mm. Probably you are wondering why the difference? Well, first, the length of the engine's stroke will affect the amount of advance required. A short stroke engine with 2mm advance will have considerably more advance measured in degrees of crankshaft rotation than a long stroke engine with spark timing of 2mm before TDC. For example, a 125cc engine with a stroke of 60mm and 2mm ignition advance has 18.8

CHeck compression to be sure. If it is 160, you may be able to run +4 timing and pump gas. I had a stocker with 155 psi and +5 timing and it ran great on 93 octane.

YFZs have issues, especially older than the 2006, or whenever they added the oil mod. I'd stay away from older than 06 if you go with the YFZ. HOnda 450Rs seem to bullet proof, however. You'll spend too much time and money making the Banshee as fun on the most trails as even a bone stock 450, imo.

You gotta fax number and I can send you printouts of all the curves. I don't have a scanner, and it won't let you print to file or post the files.

Opinions (and theories) on break in methods and what oil to break in with area a dime a dozen. I've broken motors in on both oils and used different methods and don't know what difference it made on the track or longevity of the motor.

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Good question. As long as the gasket will seal, I don't see why it wouldn't "run", but I don't have a clue what effect it would have. I doubt you could use stock base gaskets.

Lose the stop on the tumb throttle assembly and tighten the cable as much as you can (without raising the slides) on the bars. It's sometimes a fight between being able to open the slides up, and having them open before you ever give it gas. Good luck.

YOu got a 72mm Cub? Super Cub??

Ok. Then next question...the machine shop says that it is an aluminum cylinder (not steel). Is that ok? I'm not familiar with this at all, and this is not my bike. I'm just asking for a friend.

I was wondering the same.