Hawk 250 sputtering when hot

stang07 · 06-29-2020, 11:56 AM

my bike was running fine, but now it spits and sputters when it's hot. Until it warms up, it runs fine. I have a 110 jet installed and the fuel mixture screw out 1 and 1/2 turns. I'm about at the end of my rope here!

TheChairman · 06-29-2020, 12:44 PM

What does the spark plug look like?

You may still be lean. I'm having the same problem at higher speeds. I have a 115 main installed and it seems to miss and stutter above 50mph nearer WOT. Fairly sure I need to go up to a 120 main.

**JerryHawk250** · 06-29-2020, 01:34 PM

Adjust the valves, they are probably set to tight. Valves aren't sealing once it up to running temperature.

stang07 · 06-29-2020, 01:36 PM

I adjusted the valves, and it seemed to do the trick! I ran it hard for about seven or eight miles. It felt great. Thank you!

06-29-2020, 11:56 AM	#1
stang07 Join Date: Feb 2020 Posts: 35	Hawk 250 sputtering when hot my bike was running fine, but now it spits and sputters when it's hot. Until it warms up, it runs fine. I have a 110 jet installed and the fuel mixture screw out 1 and 1/2 turns. I'm about at the end of my rope here!
	0

06-29-2020, 01:34 PM	#3
JerryHawk250 Moderator Join Date: Oct 2016 Location: Houma, La. Posts: 11,707	Adjust the valves, they are probably set to tight. Valves aren't sealing once it up to running temperature. __________________ 2024 Linhai 300 ATV 4x4 2023 Lifan Lycan 250 Chopper 2023 Venom Evader 2022 Lifan KPX250 2020 Kawasaki Vulcan S (Sold) 2004 Honda ST 1300 2016 Black Hawk 250 (sold) Keihin PE30 carb,125 main,38 slow.Pod filter,ported & decked head 10:1 CR,Direct Ignition Coil,15/40Sprockets,NGK DPR8EIX-9,De-Cat,Dual Oil Cooler,Digital Cluster 2016 Cazador180 XL 2014 Coolster150 JerryHawk250.com My YouTube Channel
	1

06-29-2020, 12:44 PM	#2
TheChairman Join Date: May 2020 Location: Philadelphia Posts: 115	What does the spark plug look like? You may still be lean. I'm having the same problem at higher speeds. I have a 115 main installed and it seems to miss and stutter above 50mph nearer WOT. Fairly sure I need to go up to a 120 main.
	0

06-29-2020, 01:36 PM	#4
stang07 Join Date: Feb 2020 Posts: 35	I adjusted the valves, and it seemed to do the trick! I ran it hard for about seven or eight miles. It felt great. Thank you!
	1