J-Madd

I have a friend with a 397 Cub that kicks 105 psi. His compression ratio is probably ridiculous, though. It's the fastest 0-400 cc Banshee that I have ever saw run in 300 ft. A tenth faster than the current "record." Anyway, as mentioned - check the thickness of that base gasket; should probably be 0.012". Get that squish down a little. You may need it a little looser than us drag racers; but not that loose. You can probably get by with lower compression and timing also. You'll create too much heat with high compression and timing racing that oval, imo.

Clean and sync your carbs. That's not excessive smoking, just that the left side is not smoking - that is the problem. If that doesn't work, let us know.

I would think that compression is low. 890 ft elevation is not enough to loose 20 psi over sea level. Imo, a milled head is just as good as a cool head for a stock cylinder, stock stroke motor. I have mine milled 0.020". Put the compression at about 150 psi at 300 ft elevation. Are you holding the throttle wide open and kicking until the gauge stops moving?

The loop on the clip goes toward and into the notch in the case.

Holy hell I'v had that clip come off several times and it puts some metal shavings in the oil and scratches the clutch basket a little, but no real damage. I think your problem is that a piece came loose from the starter assembly. #3 in this diagram can be the culprit. click Easy fix.

Well, I vote for air leak then. Just missed your post!

Way lean = deto and burn a hole in the piston. You're motor requires more fuel hillclimbing (especially at the top) due to the load on the engine. If you just randomly checked the plugs, you didn't get a reading of what was going on at the top of the climb regarding the jetting. You also could have had an air leak.

Thanks a lot man!! I've been looking everywhere. They had what I needed.

Tim at Titan Racing just fixed a crank with a bent rod for a friend of mine. $175 parts, labor, return shipping, and few intake gaskets.

The chain would most likely not work. You'll need to add a half link. 14/41 and 15/44 is the same ratio. You probably won't notice that much difference with your set up. The bigger back sprocket puts more "leverage" on the axle, providing more torque, I think.

Check your plugs for signs of detonation (plugs backing out, burned strap, metal flakes on plug). Make sure the jetting is not lean. If those aren't the problems, it may just be revving past the limits of the pipe. Those pipes will restrict the rpms at which that motor can make power. Try some CPIs, Shearer's, or Vito's Fat Bastard pipes.

Like this - but only left handed threads.

I think all ATF Type F is about the same as far as what it does for your tranny. I've ran generic brands that I'v never heard of.

Yeah, I'm leaning toward the oil also. Maybe try something different.

I always ran 15/42 on my Cubs with that size tire (assuming 72 r/o.) With 74 r/o I go to 15/43 - 15/44. What ever you do, gear it to leave in 2nd. If it constantly bogs in second, lower the gearing until it leaves hard.

There's your answer^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Just convert the PWKs yourself. Nothing to it. You may want to get some billet bowls also.

Could be reeds, air leak, or dirty carb, but Im still gonna say the carbs aren't sync'd. Check them again. I fought that for a long time and swore the carbs were in sync. Somehow the cable was in a bind given the appearance that they were sync'd, then later while riding it would free itself, then they would be way out of sync. If that doesn't work you could swap carbs left to right and see if the problem follows.

Most likely yes. Diameter, taper and length are all different with those.

I have a headache from reading that . j/k I always sync the carbs by looking into the carb body. Not sure how reliable that window is You may want to take a look.

Unplug the TORS and check that the wires to the ignition coil have not come off.

Oddly enough, I made some dyno pulls with the ignition coil zip tied to the frame. Not grounded whatsoever. I've also ran without the black wire coming from the stator grounded (that may be just for the lights ?)

I spray wd40 in the cylinders and kick it over few times. I may or may not drain the carbs.

WTF do you have? You could have between 30 and 150 hp

Yeah you can eliminate the plate if you have the cord and software to add more timing on the dyna. Any pre-programmed dyna setting could use a little timing on the plate on some motors, depending on octane of the fuel of course.