J-Madd

X3. I just got in 4 jets today from them.

Better to just buy another crank.

Did you verify that it's not firing or just making that assumption?

My TM 38 Mikunis have 22.5 pilots!!?? And its still fat as hell on bottom and not close to lined out (16 Mil Cheetah).

I run a shaved head on my unported stocker that kicks 155 psi. I run +5 timing and 92 - 93 octane for years now. I couldn't tell you trapped volume or UCCR, but our motors should be very similar in that area.

I'm all for shortcuts, but no way in hell would I put a new seal in there without the cases apart. Yamabond won't fix the seal. It may be leaking around the inside of the seal, which is exposed to the moving crankshaft. Also, leaking around the key-way usually won't leak bad enough to do what you describe.

I like the bar to be about the same length as the wheelbase on a ridgid. On a strutted stock chassis I think I ran about a 6' bar, but with a +8 swingarm. On the stocker, I'd ride up towards the tank and it would pick up the front and carry it for over half track (if not over 200 ft).

On an unported 421 Cub, I think you can pick up some hp with Shearers (either OOF or IF) vs the CPIs.

What does the dyno graph look like at 7000 rpm?

You probably have this fixed by now, but it's not a good idea to change the mains and needles at the same time. Get the mains dialed in first, then the needles, then the pilots. It's easier that way.

I gave away a 4 mil 115 mm rod hot rod crank with trashed bearings on it. I had another one rebuilt, and it cost more than half of what a new one is.

There has been some confusion in recent years over Shearer's "new" and "old" design. The only "new" design is any stamped small bore pipe. The "old" design was the hand coned small bore pipes. He told me all the stamped ones are exactly the same and there is no newer stamped version. I called him about a year ago to order the "new" design and he told me the 3 yr old stamped pipes I already had were the same; so I didn't order any. I asked him several times why people (including myself) thought there was a new, better stamped version, and all he kept saying is that all the stamped ones have always been the same.

If it pushes coolant out when its not hot, it's leaking around the head gasket. If it waits until it gets hot, it could either be the head gasket or it's just running too hot.

Nice. Man, 1/4 mile seems scary to me. I'm even worried to try the 1/8 mile for slight fear of wrecking and/or breaking and wearing the drivetrain and engine.

Again, depends on exhaust port duration. I dynoed an (alleged) RDZ 10 mil Cub with RDZ pipes and with BB CPIs (the semi hand coned kind) and the CPIS made better power everywhere. The ex port was 200*. I have been told by builders that the CPIs favor the higher duration, and I confirmed that on the dyno.

I have both and was at the dyno last week, but didn't think about testing them. I did try them at the track and couldn't tell much difference. By looking at the VF3s with cascade stuffers, and the VF2s (with original stuffers); the VF3s are a hell of a lot bigger on the carb side. For those that say the 2s flow more and make more hp, did you port the cages, or modify the stuffer?

Sounds lean to me.

What kinda times do you run? I've never ran asphalt, so I don't really know what's considered a good time (for a 4 mil Cub). My friend's runs 6.1 - 6.3, and the 60 ft is not very good. He said he just has to roll out, then get on the throttle to keep from bogging or blowing the tires off. He's still working on getting the clutch right I'd bet.

Choke tube

Guys with Cubs that I know run 19/38 or 39 in the 8th, and they are out of gear at about 106-110 mph.

Definitely.

15/41 would be a start. If you don't have 6th gear topped out with that, go up a tooth at a time on the back until your maxxed out in 6th at the traps.

The cable is too long, there's nothing wrong with the perch. Is it a Motion Pro cable? They are notorious for that. Stick with oem Yamaha cable if you can.

Are you even getting into 6th gear? Sounds like your bike isn't pulling the gear.

Don't forget to specify wrist pin bearings when you order the pistons. Oddly enough,they don't automatically come with them. That's a bummer when you get ready to put it all together then notice they aren't there.