Tedder

I agree that a 421 Serval would be the best choice.

Tuned correctly a ported 10mil cub (465cc) is a great setup and will be a far cheaper build than a DM. I agree that it would be worth a call to Cam (Redline Racing). Ask him how the 465 would compare to https://cpindinc.com/parts/0101-7258-115SA?category=Yamaha_Banshee

Although I haven't run those exact setups I think I can contribute some solid info backed with my own real world experience. I'm one of the oldies here with well into the thousands of 1/4 mile passes on a 4mil 421cub, hundreds on a 465 10mil cub and I have a son that ran an almost identical setup with a 392 cub. As you'd expect there's a performance increase with each step. I'm currently in the process of building a 611DM. It uses the same 64mm crank as my 10mil but with a 78 bore but where the big gains come from with the DM over cubs is it's ability to breath much better because of the MUCH larger intake and reeds. Good luck with whatever you decide

With 2.68 straight cut primaries I used TZ's on both the clutch and stator side but with my sustained high rpm 1/4 mile runs light brown color always showed up on the inside races. In never saw any galling but the color obviously indicates skidding and heat buildup. With barrel rollers they have more drag also. I'd pretty much decided on going with Max loads even though they're prone to cracking races if subjected to detonation which I sometimes get with my alcohol motors and they don't have near the TZ's load carrying capacity but for better or worse I ended up going ceramics this time. We'll see if that was a wise decision or not! Personally if I was doing a gas trail type motor I would go either Koyo or Max loads.

Other than two OEM cranks (which are very good quality imo) I've only run Hot Rods in my drag motors under 10mil. Each got upgraded outer bearings from the original Taiwan's. Over the years I've had a few welds crack but never separate like the one in your pic and one large end rod pin that snapped clean through. Luckily it busted when I was doing my dry hop before a run. I've never had a connecting rod snap.

Good place to start would be here: https://www.bansheehq.com/forums/topic/99361-what-jets-are-you-using-fill-out-this-form/ Personally I've done nothing but asphalt drags and mostly alcohol but I'd start with 165 - 168 mains and 52 - 55 pilots.

Grabbed this off of youtube. What you want starts at the 2:00 mark.

I use this on my American Racers (rear) but had to change out the heavy springs to work with light ATV tires and the rim center hole that you have has to be within the balancers cone size. *Can be had on sale or elsewhere for around $65 https://www.harborfreight.com/portable-wheel-balancer-59140.html

On asphalt I've had tire shake caused by excessive toe in. Excessive toe out caused it to wander/dart.

Agree 100% 4mil ported Serval

I can only give accurate information on full drag ported 1/4 mile asphalt cub motors so take this for what it's worth. My son and I did a ton of reed valve comparisons and nothing ET'd quicker than V-Force 2's. V-Force 4's came in a close second and had a better low/mid range pull and would be my choice for anything but an all out drag motor.

Done properly, a plug chop only gives a read of the main circuit at wide open throttle. It's useful to me on my asphalt motors but that's all it covers.

Not sure I understand your question M18. There are a lot of motor and fuel variables but assuming a stock ignition with an adjustable stator plate most running gas are advanced +4 or 5* and those on methanol are 8 -10*

Have you looked into these? https://dragymotorsports.com/#home-hero

Yes Sir, Nice to still have a few good ones around.