my mod plans(hawk 250cc) - Page 4

w0ss · 06-03-2016, 11:14 PM

Right now I have a 20 that came with the mikuni or the 40 from the stock carb. I will try the stock pilot jet.

mq1991 · 06-04-2016, 01:13 AM

Quote:

Originally Posted by w0ss

Right now I have a 20 that came with the mikuni or the 40 from the stock carb. I will try the stock pilot jet.

This didnt occur to me when I was first working on my carb, but the lines arent as clear cut as some guides make it seem.

As in, when I changed my main jet, it DID affect how my bike idled. Vice versa, when I adjusted my pilot and air mixture screw, it seemed to also lightly affect my top end.

I think its because both jets are working at some capacity all the time, or so it seems. Like, at idle, it 90% your pilot jet and 10% main jet, and at WOT, its 90% your main jet, but there still a tiny bit added by the pilot jet. I could be completely wrong though.

Something like this chart...

http://www.jba.bc.ca/JBCycle/Resources/jet-chart.jpg

zingshoen · 06-04-2016, 03:50 AM

yup you are right, they all work together, if the pilot is too big you get unburnt fuel smell from the exhaust, and when the main jet is too big, the bike bogs at WOT.
having said that a largish pilot makes for a smooth cruise and the bike won t lean out when changing gears.
and of course it depends on altitude, air filter setup etc. but you ll get to sthe point where you max your performance and after that you can smooth it a little but you won t get much improvement.

Weldangrind · 06-04-2016, 01:40 PM

Quote:

Originally Posted by mq1991

This didnt occur to me when I was first working on my carb, but the lines arent as clear cut as some guides make it seem.

As in, when I changed my main jet, it DID affect how my bike idled. Vice versa, when I adjusted my pilot and air mixture screw, it seemed to also lightly affect my top end.

I think its because both jets are working at some capacity all the time, or so it seems. Like, at idle, it 90% your pilot jet and 10% main jet, and at WOT, its 90% your main jet, but there still a tiny bit added by the pilot jet. I could be completely wrong though.

Something like this chart...

http://www.jba.bc.ca/JBCycle/Resources/jet-chart.jpg

I first learned this concept from forum member Pete; he insists that a jet change will affect the entire operation of the carb, not just that specific circuit.

w0ss · 06-05-2016, 01:41 PM

I can't seem to find a pilot jet pack that has assorted jets. Does anyone have a link to one?

Azhule · 06-05-2016, 03:03 PM

I bought mine from an Aliexpress vendor... but I still don't know how to use those other China Buy sites

... you can list what all sizes you want to receive

http://www.aliexpress.com/item/Mikun...261503024.html

w0ss · 06-05-2016, 08:39 PM

Thanks I ordered a set.

I thought the fuel line was 1/4 id but it is to big. Any idea what the size is maybe 3/16?

Weldangrind · 06-06-2016, 12:36 AM

I think that's right. 5mm is pretty close.

w0ss · 06-06-2016, 06:04 PM

Here is a picture with the exhaust and uni filter on. Probably going to rattle can the header to be black as well.

zingshoen · 06-07-2016, 08:38 AM

unifilter should be fine with the jetting of 25 and 115. i think that s what i have installed.

w0ss · 06-07-2016, 09:24 AM

Quote:

Originally Posted by zingshoen

unifilter should be fine with the jetting of 25 and 115. i think that s what i have installed.

I have it running a 115 and 20 right now. It pops coming off the throttle. I think that means it is running lean? I have a set of pilot jets coming. I know once I have this dialed in it will be very nice. It wants to lift when I shift into second so I know I have more power. Sometimes I wish this thing had fuel injection.

Anyone know if there is an EFI kit for the hawk

newrider93 · 06-07-2016, 12:29 PM

How did the engine bolts fit with the header of the exhaust? Was it an exact fit or did you have to mod it?

w0ss · 06-07-2016, 12:33 PM

I spent some time with a Dremel widening the bolt holes on the exhaust. They don't need to widen much but they don't fit without modification. Also the Airbox touches the pipe. I went with a UNI filter so not a big deal to me. Others didn't mention that the airbox hit so not sure if I did something wrong.

Azhule · 06-07-2016, 01:41 PM

Quote:

Originally Posted by w0ss

Others didn't mention that the airbox hit so not sure if I did something wrong.

Most of those exhausts are made to "close enough" standards on the bends/mounts, I doubt you did anything wrong on the install

As for the EFI, look into "Ecotrons" they make 'small engine EFI kits', but they get spendy lol

w0ss · 06-07-2016, 01:51 PM

Quote:

Originally Posted by Azhule

As for the EFI, look into "Ecotrons" they make 'small engine EFI kits', but they get spendy lol

Ouch 600$ I expected to be able to buy some cheap chinese knockoff for 50$

06-04-2016, 03:50 AM	#48
zingshoen Join Date: Jun 2009 Location: Brisbane, Queensland, Australia Posts: 648	yup you are right, they all work together, if the pilot is too big you get unburnt fuel smell from the exhaust, and when the main jet is too big, the bike bogs at WOT. having said that a largish pilot makes for a smooth cruise and the bike won t lean out when changing gears. and of course it depends on altitude, air filter setup etc. but you ll get to sthe point where you max your performance and after that you can smooth it a little but you won t get much improvement. __________________ 1971 Garelli Gulp 50cc with open ports and 16 mm Bing Carbie + 1980 Honda XL 223 ZS + 2007 Zongshen LZX200G + DR400SM
	0

06-05-2016, 03:03 PM	#51
Azhule Join Date: Dec 2015 Location: CO Posts: 1,525	I bought mine from an Aliexpress vendor... but I still don't know how to use those other China Buy sites ... you can list what all sizes you want to receive http://www.aliexpress.com/item/Mikun...261503024.html __________________ "Think as you like... but this self proclaimed Professor is always right" - Buckshot "You never know what someone is hiding beneath their smile..." - NinjaTom - R.I.P.
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06-06-2016, 12:36 AM	#53
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	I think that's right. 5mm is pretty close. __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
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06-07-2016, 08:38 AM	#55
zingshoen Join Date: Jun 2009 Location: Brisbane, Queensland, Australia Posts: 648	unifilter should be fine with the jetting of 25 and 115. i think that s what i have installed. __________________ 1971 Garelli Gulp 50cc with open ports and 16 mm Bing Carbie + 1980 Honda XL 223 ZS + 2007 Zongshen LZX200G + DR400SM
	0

06-07-2016, 12:29 PM	#57
newrider93 Join Date: Jun 2015 Location: Missouri USA Posts: 164	How did the engine bolts fit with the header of the exhaust? Was it an exact fit or did you have to mod it? __________________ My YouTube channel where you can check out my hawk and other cool stuff: https://www.youtube.com/c/Andrew93 newrider93 AKA Andrew93
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06-03-2016, 11:14 PM	#46
w0ss Join Date: May 2016 Posts: 231	Right now I have a 20 that came with the mikuni or the 40 from the stock carb. I will try the stock pilot jet.
	0

06-05-2016, 01:41 PM	#50
w0ss Join Date: May 2016 Posts: 231	I can't seem to find a pilot jet pack that has assorted jets. Does anyone have a link to one?
	0

06-05-2016, 08:39 PM	#52
w0ss Join Date: May 2016 Posts: 231	Thanks I ordered a set. I thought the fuel line was 1/4 id but it is to big. Any idea what the size is maybe 3/16?
	0

06-06-2016, 06:04 PM	#54
w0ss Join Date: May 2016 Posts: 231	Here is a picture with the exhaust and uni filter on. Probably going to rattle can the header to be black as well.
	7

06-07-2016, 12:33 PM	#58
w0ss Join Date: May 2016 Posts: 231	I spent some time with a Dremel widening the bolt holes on the exhaust. They don't need to widen much but they don't fit without modification. Also the Airbox touches the pipe. I went with a UNI filter so not a big deal to me. Others didn't mention that the airbox hit so not sure if I did something wrong.
	1