slacker1bob

I have a 421 cub with two 35mm pwk. Is the stock petcock, and float bowls enough to supply fuel under full load, or should I upgrade to larger bowls or a pingel Petcock, I have 168 jets in it now, and when I run Olds in Glamis, the plugs look lean, but duning at a casual pace, the plugs are rich. 168 jets seem big to me, so thats why Im wondering if its not getting enough full, and as far as I can tell, the floats are correct.

Get an adjustable plate, just as easy to install and more versatile. As far as head shaving, if you are currently stock and running 93octane, your wasting money, and if you just mildly shave your head, your still fine at 91 octane. You need to check your compression after your head is shaved. 130psi and lower is fine to run 91. I have ran 91 at 140, but some advise against it

Are you asking if the slides are the same between a cr and yz? Most likely. I did the same by buying 35mm pwk carbs from various 125 bikes. I needed to buy about 5(because people take crap pictures and give bad descriptions) to put together 2 matching carbs, but there seems to be more variations. the 28mm's have just a couple major variations, mainly the presences of a top vent hose.

I sent a pair of Self ported jugs to Kevingand he could still work with them. Mine barely had any port lift/enlargement, so it was easy to still do any kind of port. Looked like yours, but like I said, I didnt ift the exaust port. It was about a 2 week turn around, and did more work than I expected

Power increase is pretty minimal, if any at all, but its more about high rpm reliability. You can safely run higher rpms and for longer duration than a short rod do to the better angel and less stresses

I have a 421 cub motor with Boss one piece billet intake and 35mm keihin pwk carbs. Is there a trick or a very narrow air filter that keeps the mid pipe from hitting the filter

I had the same problem with a stock mikuni carb. The left side would be cold and have a ton of fuel. I cleaned the carb and sincronized them and everything and could not get it right, finally I put a different set of stock carbs on and it worked perfect.