Some Hawk upgrades - Page 3

Megadan · 04-17-2019, 06:22 PM

Quote:

Originally Posted by OneLeggedRider

Drilling the pilot is scary and it's something we were taught never to do in school. But considering we can't get a bigger pilot which I know it needs.. And old school racers did it on the regular. They even bored the venturi though so I wonder how much they understood about fluid dynamics lol.

I'm thinking drill the pilot to.45mm, and go to the 110 main jet. If that's not satisfactory remove the 2 washers from the needle and turn the mixture down to 1.25 turns out. If that doesn't work I'll simply replace it with a nicer carb. I'm not rich but parts for these things cost almost nothing. Ask me how much I got in my Scrambler or how much I paid for the UFO carb. Big difference.

I was taught the same thing concerning jets, because there is more to it than just the hole size, but I do know that you can often get away with it going 1 step up in size with little to no ill effects. It's when people try to drill from say a 40 to a 50 or larger that issues tend to arise.

Honestly, i want to install my flat slide, but I have yet to find an intake that will allow me to install the stupid thing.

NzBrakelathes · 04-17-2019, 07:37 PM

Quote:

Originally Posted by OneLeggedRider

This isn't my first rodeo and I'm sure it will be resolved soon. I actually made a generator run using a plastic citrus fertilizer sprinkler for 6 months. My worst carb was experience was replacing a motor in my '76 CJ 5 with a newer emissions motor. Seemed like no matter what I did it wasn't right, but I eventually figured that out too.

Drilling the pilot is scary and it's something we were taught never to do in school. But considering we can't get a bigger pilot which I know it needs.. And old school racers did it on the regular. They even bored the venturi though so I wonder how much they understood about fluid dynamics lol.

I'm thinking drill the pilot to.45mm, and go to the 110 main jet. If that's not satisfactory remove the 2 washers from the needle and turn the mixture down to 1.25 turns out. If that doesn't work I'll simply replace it with a nicer carb. I'm not rich but parts for these things cost almost nothing. Ask me how much I got in my Scrambler or how much I paid for the UFO carb. Big difference.

Back in NZ it was VERY common to up a jet via drill it out, VERY common but being far away we simply learnt to do things another way. I also bored out the venture on my KTM to match the spec to the 560SMR motor I fitted in the EXC frame.

Maybe in the USA you have or had the luxury of running to the shop to buy what you needed or you got BS to simply buy more parts.

My CQR I drilled to 0.45 and runs fine - air screw 1.75 turns, fail to see why in the USA or California it causes issues or cancer lol