Tuning and jetting hawk 250 - Page 3

Megadan · 05-14-2020, 01:16 AM

Quote:

Originally Posted by CaptainKP

So, a little update and additional question.. I got the pilot jets in today to replace and pulled out the stock one and to my surprise it was labeled 42...

I ordered a 25 and 27.5 and put the 27.5

How the hell would going from a 42 to 27.5 make sense? Now I'm questioning every sound I hear as it idles

Others have had this same question before. The jets that come in the carburetor are stamped with what seems to be a Keihin jet size, but if it is the VM mikuni style jet, just use the ones you have. It will make tuning a lot less confusing. Believe me, if that was an actual Mikuni 40 size pilot jet, your bike would flood out at idle.

CaptainKP · 05-14-2020, 10:19 AM

I dont think so. I have a Mikuni clone and ordered Mikuni jets from jets r us from a link provided here on the forum.

I switched out the main jet already and those numbers matched up to what you would expect. I can see the hole is clearly way bigger on the pilot jet that is labeled 42.

So confused.

Edit: Posted before I saw MD's reply. Will try out the 27.5 for a while and see how it goes. Its an official mikuni. The bike was noticeably more quiet when idling. My girlfriend even made a comment about it. But if I blipped the throttle it was stalling out. It got better as it warmed up

Megadan · 05-14-2020, 02:14 PM

Quote:

Originally Posted by CaptainKP

The bike was noticeably more quiet when idling. My girlfriend even made a comment about it. But if I blipped the throttle it was stalling out. It got better as it warmed up

You will need to dial in the idle mixture for the pilot jet you selected. I would personally say to try the 25 first. I only found it to be a teeny tiny bit lean on a bike with full bolt on upgrades at part throttle which is why I had to switch to the 27.5.

The 27.5 idle mixture for me ended up being between 1 and 1 1/4 turns out.

The 25 was a bit more than 1 1/2 turns out, close to 1 3/4

CiscosHawkLife · 09-07-2020, 01:45 PM

Im new to riding I got a hawk 250 as well. I live in florida and i got a mikuni carb with 110 jet on it and im still having troubles with the choke. It only stays on with the choke and as soon as i turn the choke off it turns off any help on this?

Deckard_Cain · 09-08-2020, 09:42 AM

Quote:

Originally Posted by CiscosHawkLife

Im new to riding I got a hawk 250 as well. I live in florida and i got a mikuni carb with 110 jet on it and im still having troubles with the choke. It only stays on with the choke and as soon as i turn the choke off it turns off any help on this?

Firstly, make sure you are solid on which way is choke OFF, that would be all the way DOWN. Sounds silly and simple but far too many people get it backwards.

Second, what size pilot jet are you using and how many turns out on the mix screw? Genuine Mikuni or the clone?

Your pilot circuit is not right..

treysive · 05-03-2021, 05:29 PM

i know this an old thread but i could really use some help.

i live in florida and have the mikuni carb with new exhaust and pod air filter.

screw is turned out 1 1/2
main is 115
pilot is 27.5

it idles a little rough at 15-1600 RPMs

it smokes a little at idle and when i rev it up the smoke seems to go away.
i've done the valve adjustments too

should i try to go to a 25 pilot?

JakeD · 05-03-2021, 10:16 PM

Is there a chart for altitude adjustments? I’m at 2300 in high desert... Mikuni clone.

jseals8725@gmail.c · 12-01-2021, 08:13 PM

How turns out should I start with the fuel adjustment screw the carb has a 110 main jet on 2 Noch needle jet

Kari · 08-12-2023, 01:26 PM

I have a 2022 hawk 250 with that bogs down at quarter throttle and idles rough after warming up. I have a stock carb with 40 pilot and 104 main with the air screw 1.5 turns out and the needle on the second clip. If i move the needle to the first clip the whole throttle runs lean and if i move it to the third clip the engine rpms instanly go way too high. If i turn the air screw out the rpms go to high again and if i tighten if the bogging at quater throttle gets worse.
My mods that affect the mixture:
Nibbi 48mm air cone filter
Full jfg racing exhaust system
Ac racing cdi box(not sure if that affects the air/fuel mixture)
If anybody has suggestions let me know please

09-07-2020, 01:45 PM	#34
CiscosHawkLife Join Date: Sep 2020 Posts: 1	Need Help Im new to riding I got a hawk 250 as well. I live in florida and i got a mikuni carb with 110 jet on it and im still having troubles with the choke. It only stays on with the choke and as soon as i turn the choke off it turns off any help on this?
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05-03-2021, 05:29 PM	#36
treysive Join Date: May 2021 Posts: 1	smoke out exhaust i know this an old thread but i could really use some help. i live in florida and have the mikuni carb with new exhaust and pod air filter. screw is turned out 1 1/2 main is 115 pilot is 27.5 it idles a little rough at 15-1600 RPMs it smokes a little at idle and when i rev it up the smoke seems to go away. i've done the valve adjustments too should i try to go to a 25 pilot?
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05-03-2021, 10:16 PM	#37
JakeD Join Date: Apr 2020 Posts: 31	Is there a chart for altitude adjustments? I’m at 2300 in high desert... Mikuni clone. Last edited by JakeD; 05-04-2021 at 12:27 PM. Reason: More info
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12-01-2021, 08:13 PM	#38
jseals8725@gmail.c Join Date: Aug 2021 Posts: 1	MYK VM26 30mm Carb Carburetor PZ30 200cc 250cc for Mikuni How turns out should I start with the fuel adjustment screw the carb has a 110 main jet on 2 Noch needle jet
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08-12-2023, 01:26 PM	#39
Kari Join Date: May 2023 Posts: 2	Hawk 250 pilot jet/needle problems I have a 2022 hawk 250 with that bogs down at quarter throttle and idles rough after warming up. I have a stock carb with 40 pilot and 104 main with the air screw 1.5 turns out and the needle on the second clip. If i move the needle to the first clip the whole throttle runs lean and if i move it to the third clip the engine rpms instanly go way too high. If i turn the air screw out the rpms go to high again and if i tighten if the bogging at quater throttle gets worse. My mods that affect the mixture: Nibbi 48mm air cone filter Full jfg racing exhaust system Ac racing cdi box(not sure if that affects the air/fuel mixture) If anybody has suggestions let me know please
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05-14-2020, 10:19 AM	#32
CaptainKP Join Date: Apr 2020 Location: Atlanta, GA Posts: 58	I dont think so. I have a Mikuni clone and ordered Mikuni jets from jets r us from a link provided here on the forum. I switched out the main jet already and those numbers matched up to what you would expect. I can see the hole is clearly way bigger on the pilot jet that is labeled 42. So confused. Edit: Posted before I saw MD's reply. Will try out the 27.5 for a while and see how it goes. Its an official mikuni. The bike was noticeably more quiet when idling. My girlfriend even made a comment about it. But if I blipped the throttle it was stalling out. It got better as it warmed up
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