J-Madd

I've had problems with the acorn nuts many times...the threads will come out when tightening to torque spec. It seems that the studs are sometimes too short, or the head is milled too thick in the area around the studs.

That's half price of an average USED complete pvl....

You're either running some tall ass tires, or rapping the engine to an unobtainable rpm, according to the link above.

Is that the old air cooled engine? The 2 that I've seen didn't run as good as a decent twin cylinder at the track.

Those are damn good times without a bar!! :beer:

Also unplug TORS and check the pick up coil gap. Make sure you're kill switch is either working or bypassed properly.

What kind of 60 ft times did you get with 13 pdls????? Don't see how those would work at all at the track, at least on my 4 mil. A 611 DM will need some paddle for sure. 16 extreme staggereds on 25x10x10 or 25x11x10 would be a nice choice, imo.

Stock stroke? Definitely ok for a 4 mil......and may work just fine on a stock stroke good drag ported engine.

Yes, there is a puller.

Tire size? There's a gearing calculator somewhere that will speed vs. rpms. Find it, then determine what rpms you think that motor will pull in top gear, with your gearing and tire size.

Odd...Jim had domes for my (yet to make a remotely decent pass*) 10 mil cut to 18.5 cc and it has around 190 lbs psi and 0.520'' squish. *carb and ignition issues

265 lbs ridgid (stretched stock frame) 14 mil Cheetah. 245 lbs Suspended 16 mil Twister. TBA twister in new chassis.

Yep. Upgrade your clutch and run HD springs.That's your problem. Is your oil black? Can you smell burnt clutch in it? I'd guess yes.

No..it won't shift to 5th going down the track. I can beat the hell out of the shifter and it will shift sometimes. It first did this my very last pass last year....and continued to do it 3 out of 4 passes already this year. I'm gonna pull the forks out of an extra motor anyway and fix the burr on the gear.....surely that will fix it.

Yeah, it's talked about many times in that book...

I also disagree with that statement. Maybe some oxygenated, or exotic race fuels are close to alky, but a hell of a lot harder on the motor, run a lot hotter, and are $$$$$$.

Not likely electrical if the problem didn't follow the plug wires.

I've ordered new shift forks but not sure they will be here in time for the PS race..but the old forks look great. However, the dogs(?) ("ramps" or whatever they are called) on the 5th gear have small burrs on them. It seems to engage fine while turning the adjacent gear - bear with me as I explain. I hold the transmission shaft vertically and then turn 1st gear (adjacent to 5th gear) which in turn, engages/moves the 5th gear up as the dogs hit, as it should. I do get to a rough spot after a few turns, but it doesn't seem that bad. Could this be the shifting problem? All other gears shift fine, btw.

I have seen that happen as well. I have had to replace a stock carb to correct that problem. We never did find out what was wrong with the carb on that one.

Man I have heard the opposite!!! I don't think there is a cut and dry answer to BB vs SB other than ask your builder, as mentioned, or run SB on out of the box Cubs. I'm trying to run BB on my new 10 mil Cub (which is currently a turd for whatever reason-jetting, air leak..something) and SB on my other Cubs.

If it's unported, and using stock gaskets you should be fine with 93 octane, not sure about 90.. Not doubting that CR is disproportional to static compression, but too many run this same setup with zero issues on pump gas (93 oct).

K & N filter, re-jet the carbs, drill out your timing plate to move it to +4 or +5, mill the head 0.020''. You should be able to do all of that for well under $100.

I run 20 cc gas domes with alky on mine, and it runs pretty good. Not sure how much more benefit I'd get out of changing to alky domes.

Air leak and deto would be my guess. You'd have metal in there if some foreign material got on top of the piston. What's the plug look like?

So you had half of the spring get all the way into the transmission area of the case (where the drain plug is located), and there was not metal in the oil???????? Not even sure how it could get in there, much less not do any damage.