Gonna try to run the stock Hawk carb

[OneLeggedRider]

Well with some encouragement from Jerry I decided to see what can be done with the PW30. I just ordered a 110 and 115 main using Dan's link to Jets R Us. $15 isn't bad but I'm surprised there was any shipping considering the 2 tiny jets can easily fit in an envelope.

Now on to the fun stuff. The bike didn't wanna run even when warmed up, and would only do so on half choke with the idle screw really turned up. I removed the plastic plug for the fuel mixture screw and IT WAS FULLY SEATED!! No wonder it didn't wanna run, it was having having pull off the needle valve to get anything. So I backed it out 1.5 turns and went on to the next step. It wasn't pretty but I used my dremel to slot the 3 bowl bolts and removed them. I didn't have a couple suitable washers for the needle and I think I'm gonna replace the 3 slotted screws with something better. I thought about slapping it back together but I'm just gonna wait for the jets to arrive in a couple days.

[OneLeggedRider]

A couple pics of the slotting

[JerryHawk250]

I would put it on and tune the idle mixture so you can run it through a few heat cycles.

[Megadan]

Yeah, the shipping costs on small items is ridiculous. It's not just JetsRus that ensd up with silly shipping prices either. Blame the shipping companies for their minimum size/weight standards.

[OneLeggedRider]

Just .89 cents covered the hardware I needed, and the local hardware is only 3 miles away lol. My question is if you gotta put spacers on the needle jet, maybe you need a bigger needle and jet, like alot bigger than a 120..

[JerryHawk250]

The stock needle doesn't have any grooves in it to raise or lower the needle for tuning partial trottle. You may not have to shim it but most have had to raise the needle even on the Mikuni carb. 120 main will probably be too rich.

[NzBrakelathes]

Seems for a budget end, a set of jets a needle would suit?
Most all cheap bikes here run the keinhi carbs and work at least fine
I’ve looked at things but guys seem hell bent on copying others link etc which kinda cuts me out of the picture
I’d say a kit for stock carb with rught bits or a mikuni carb with some extra jets might suit the market better

[Digger]

I bought a carb kit on ebay the pilot jet was wrong but the kit had the correct bowl gasket AND an adjustable needle. The pilot jet on a stock Hawk is on the lean side.my next mod is to drill out the pilot jet to .018.. stock is .016. The stock carb is just fine, just needs to be tuned

[OneLeggedRider]

Might of had one too many lastnight.. The one bowl screw has to be a little shorter and the shorter ones I picked up were too short so I'm gonna grab another long one today and cut it down. I'm hoping the washers aren't too big, but they were the smallest he had. I'm gonna throw it together today and see how it works. It's -4° out there so it probably won't be a long test run with the door open lol.

[JerryHawk250]

Originally Posted by OneLeggedRider

Might of had one too many lastnight.. The one bowl screw has to be a little shorter and the shorter ones I picked up were too short so I'm gonna grab another long one today and cut it down. I'm hoping the washers aren't too big, but they were the smallest he had. I'm gonna throw it together today and see how it works. It's -4° out there so it probably won't be a long test run with the door open lol.

It's hard to tell in the picture but if the washers look thick you can try using one first. You just want to shim it up about equal to one notch spacings of a normal needle.

[Megadan]

If the washers are about 1mm thick, then they would give the same needle adjustment as 1 notch down on a normal needle with 5 notches of adjustment. The taper of the needle is a different question, and I don't think anybody to date has measured it.

I always found it interesting that some people found the 40 pilot jet of the stock carb as too small, when I found it to be almost perfect once the idle mixture was dialed in (usually between 1 and 2 turns out). Never once giving the slightest hint of hesitation below 1/8th throttle that would indicate a lean condition. The needle on the other hand, going back to the taper, is either not aggressive enough or the fixed clip position is relatively high (equivalent of second notch) and causes a lean spot right around 1/8th throttle when the transition takes place. This is why shimming it works so well. Granted there are a lot of environmental factors that could affect this, so making any sort of comparison is somewhat moot. Stepping up to a .018 drill size = 45 keihin jet size.

[OneLeggedRider]

Omg.. used both washers and 1.5 turns on the fuel mixture screw. Fired right up, within 2 minutes I was able to turn the choke completely off, and within 5 minutes I was able to idle it way down. Good throttle response and purring like a kitten. Cant wait to put the 110 jet in now!

[JerryHawk250]

Awesomeness.

[Ariel Red Hunter]

Originally Posted by OneLeggedRider

A couple pics of the slotting

Nice custom job on the screw slots! Yeah, I know, shipping is high. But remember, in my day, parts like these were not available for EITHER blood, or money!..ARH

[Megadan]

Amazing how different they run when they arent so choked up on fuel lol.