|
05-29-2020, 11:36 PM | #1 |
Join Date: Mar 2020
Location: NorthEast
Posts: 71
|
2019 Hawk 250 jetting settings and question
2019 Hawk 250 -- stock other than changing to a PZ30 Keihin from eBay.
Main jet: 110 Pilot Jet: 45 Needle: 4th notch from top Idle Mixture Screw: 1.5 turns out Altitude: 1000 ft Starts up with little to no choke (finally!) and settles into a reasonable idle. No more stalling, sputtering, and warming up for 20 minutes. Feels much fatter throughout the rev range. Definitely more pick up from 50 to top speed. Only issue I have is that once the bike is warmed up -- which doesn't take long now -- and I am riding anywhere from 10 mph up, it stutters or surges (not really a stumble) at around 1/8 steady throttle. Feels almost like a fuel injection model that is hyper sensitive and hunts between throttle on and throttle off. Any ideas? |
|
05-30-2020, 01:08 AM | #2 |
Join Date: Apr 2017
Location: Omaha, NE
Posts: 8,100
|
That 1/8th light steady throttle point is exactly the point where pilot jet sizes show their strengths or weakensses.
That is also the point where the needle starts to add fuel, so if the pilot jet is not too big, then lowering the needle to the third slot should lean out that point just enough to stop that surge feeling that you are getting. Since the needle adjustment is a lot easier and faster to do, I would try that first. If it still does it, then try a 40 or 42 pilot jet. If I were a betting man, I would wager on the needle adjustment just going off of a 110 main AND a 45 pilot on a stock bike. That's definitely on the heavy side.
__________________
Hawk Information and Resource guide: http://www.chinariders.net/showthread.php?t=20331 2018 Hawk 250 - Full Mod list here. http://www.chinariders.net/showpost....62&postcount=1 2024 Royal Enfield Shotgun 650 https://chinariders.net/showthread.php?t=34124 |
|
05-30-2020, 09:37 AM | #3 | |
Join Date: Apr 2020
Location: Atlanta, GA
Posts: 58
|
Quote:
|
|
|
05-30-2020, 01:12 PM | #4 |
Join Date: Apr 2017
Location: Omaha, NE
Posts: 8,100
|
I only speak in official jet numbers. If you have a carb using Keihin jets, I use Keihin jet sizes. If you have a Mikuni, then it's mikuni sizes. Doesn't get more official than that. Chinese jet sizes don't count in my opinion for the reason you stated.
__________________
Hawk Information and Resource guide: http://www.chinariders.net/showthread.php?t=20331 2018 Hawk 250 - Full Mod list here. http://www.chinariders.net/showpost....62&postcount=1 2024 Royal Enfield Shotgun 650 https://chinariders.net/showthread.php?t=34124 |
|
06-11-2020, 12:23 AM | #5 |
Join Date: Mar 2020
Location: NorthEast
Posts: 71
|
Wanted to give an update on the setting change. Lowering the needle to the third slot (as Megadan suggested) fixed the issue. Thanks!
Feels much, much better now. I'm always amazed at how a properly tuned carb makes a bike feel so much better. It's nice to be able to do that on these bikes, compared to all the technological wizardry we have to deal with on modern bikes. Snatchy fuel injection gets real old. |
|
05-30-2020, 12:33 PM | #6 | |
Join Date: Mar 2020
Location: NorthEast
Posts: 71
|
Quote:
Thanks, that's where I'll start. |
|
|
05-30-2020, 11:00 AM | #7 |
Join Date: Jul 2018
Posts: 64
|
Stock carb? If so, do a internet search for pz30 carb tuning. Very detailed and will answer all your questions.
Good luck. |
|
|
|
|
|