[thread pitch]

So 18mm 1.0 die to clean up threads

[thread pitch]

Does anyone know the thread pitch on the shaft the front sprocket goes on? Nut fell off and the chain hit threads a bit.

[dome cc for 300ft]

I had someone measure my cubs and they said the port timing were factory. So it runs pretty hard but is just cleaning them up going to help that much. Or should I have someone bump the exhaust transfers up for me?

[Pingle dual fuel petcock]

Still have this

[dome cc for 300ft]

Thank for giving me a honest answer. Im just local river racing we tape off 300ft

[dome cc for 300ft]

300 ft drags at sea level

[dome cc for 300ft]

What cc domes are people running on there 421 cubs on race gas

[421 needles]

Idk how to post pic I can text them to someone

[421 needles]

I have a 421 cub on 100LL the main and pilot are dailed. 160/48

The issue is if you rev it once its fine but if you rev it again it makes a bogging sound out of carbs. 39. Pwks DGH neddle in the middle. Do CEL wirk good on cubs. Shearer sb/oof

[18 cc domes]

Should be fine 100LL @7degree timing drag race only

[18 cc domes]

.015 base not sure about squish

[18 cc domes]

Sea level

[18 cc domes]

18 cc domes on a 421 cub I get 180 psi. Does this sound about right?

[421 cub small bore shearer vs big bore]

I need to be able to run this bike at least 10 passes back to back. We just grudge race but I cant just run 1 or 2 passes. Timing back to 4 and some bigger maisn where installed now I just need some test hits.

[421 cub small bore shearer vs big bore]

At 165 mains the plugs where black and wet going to start there.

[421 cub small bore shearer vs big bore]

95380 im going back where I know the jetting is right and backing timing down to 4 it felt good there. Still going to double check reeds.

[421 cub small bore shearer vs big bore]

Heat soak .

please explain I want to learn

[421 cub small bore shearer vs big bore]

Big bore pipes pulled 17-42 2nd gear launch with 160 main jets at 4 degree timing.

 

Now small bores with 15-42 2nd gear launch 158 mains at 7 degrees seems like it should be easy to pull.

 

It will pull hard first 2 passes then it does a weird bog when dumping the clutch

after that. Im going to check for a broken reed tomorrow

[421 cub small bore shearer vs big bore]

Pwk 39s 48 pilots 158 mains av100ll gas

[421 cub small bore shearer vs big bore]

Timing is at plus 7

[421 cub small bore shearer vs big bore]

I have a 421 cub that had big bore shearer pipes on it. It ran pretty tall gearing with these pipes but if you had to lift off the throttle it would just bog out. Now I have small bores but it seems like it dont have the power to pull long gearing any more but its more forgiving if you let off throttle. So what are your guys thoughts on this, plugs are very clean with the small bores idk if I may be too lean on mains now.

[spindle mount bearings size]

Just trying to see if my friends direct drive honda spindle mounts will work with just bearings being changed.

[spindle mount bearings size]

Does the spacer go in there too?

[spindle mount bearings size]

Direct drive spindle mounts on banshee taper spindle. What size bearings work in there or a link to who sells them. Thanks

[banshee o ring]

What size is the o ring for the water pipe outlet? Top side of clutch cover.