250cc Hawk Modifications (The Necessities)

[Gunrunner Doc]

Hello all, first post for me under tech specs and performance. This is for my 2015 250cc Hawk dual-sport. I've posted in another thread detailing how to get it titled in Georgia, and I'll post one more under reviews to outline my experience with Killer Motor Sports.

Once I received the bike, I had to bolt in the rear suspension and put the front tire on. All in all, I finished putting it together and had the engine turning over in under an hour. And I've never owned or worked on any bikes.

Battery: I filled up the battery that came with it, but it only lasted me a few months before crapping out. I ended up replacing it with a "Battery Tender BTL14A240C Lithium Iron Phosphate Battery" that I found on Amazon. It fits perfectly in the existing battery box without modification. There's a few extra Battery Tender cables you can buy to make charging easier and to allow you to plug up D/C devices like your cell phone charger.

Carburetor: I haven't been able to put it on yet, but I decided to upgrade the carb to a Mikuni VM26 carb (30mm.) The stock one is incredibly difficult to get running at a pleasurable and consistent setting; I find myself having to adjust the idle screw constantly, especially due to weather and how warm the bike is. I'll post more when I've made the switch. Also bought some new jets as well.

Annoying beeping turn signal: As you may already be aware, the turn signal makes an incredibly annoying beeping noise when lit. The device for that is actually under the seat, and this video will show you how to inactivate it:

Sprockets: The bike is true to the manual and does definitely top out around 60MPH. But you don't want to stress your engine on the highways by ragging it out constantly just to get to a safe speed. But of course you don't want to give up too much torque, either. So I found the highest speed I was comfortable with pushing my bike at continuously, and I used the following chart to determine what gear ratio I should have if i wanted to attain a certain speed: http://www.motosport.com/blog/the-ul...-gearing-guide (I've also attached it below)
The stock gears were a 15t front/50t rear (gearing ratio 3.33). I ended up only changing the rear sprocket down to a 40 tooth JT sprocket from Amazon (JTR269.40) for a 2.67 gear ratio. Now I can comfortably cruise between 55 - 70, and the loss of torque isn't uncomfortable. I think the only thing I wouldn't do is ride on the interstate (I could, I just don't want to die.) For purchasing purposes, I've read elsewhere that this bike is heavily cloned from Honda pieces, and that any sprockets you may want to buy will be the same as what fits a 1985 Honda XR185. This held true at least for my purchase. *Note, you will need to remove a couple of link from the stock chain to use the sprocket combo I used. Be sure to measure it out for yourself, and if you don't want to cut the chain, think about changing out the front sprocket.

And that's it so far. I only made the modifications I needed to to make this thing safe as a highway vehicle. I'm not really concerned with having the fastest Hawk on the road. Questions, comments, and criticism are warmly welcomed. Again, for title issues or a review of Killer Motor Sports, see my other threads.

[JerryHawk250]

Welcome to the forum. I to have gone with the 15/40 tooth combo on the sprockets a think it is perfect. The stock carburetor is good. You just need to crack it open and change out the main jet to a 110 or 115 and uncap the idle mixture screw and turn it out to about 1 1/2 turns to start with. Shim the needle with 2 small washer. After I did those mods to the stock carburetor it will start with out chocking it and will idle. Motocheez has a youtube video on how to do it. FWI: you may still have to change the main jet on the Mikuni carb too

[Gunrunner Doc]

Just here to update. I finally installed the Mikuni carb, 125 main jet, and also performed the exhaust and airbox mods that Motocheez shows on YouTube.

My biggest mistake initially was grossly underestimating how much more airflow I was getting. I initially started out with a 115 main jet, which was great for the new carb without any exhaust mods or airbox mods. After performing the mods, the bike was just running so lean, even when I switched out the main jet for a 120. Ultimately settled on a 125, but I would have experimented with a 130 if I had one. Cold starts are definitely MUCH easier now, and I feel like I'm getting better mpg. Throttle response is much better, and I'm getting substantially better torque going up hills and getting up to speed. The new exhaust also sounds much deeper, and it's just enough more volume without being obnoxious. I don't think Motocheez explains this in his video, but the new exhaust is pretty much just the pipe. There's no packing or anything throughout, so pretty much the only thing standing between the exhaust at the headers and the open air is a 2" wide mesh screen in the muffler.

After going through this ordeal and having to remove/replace the carb so many times, I've grown fond of the idea of using a K&N universal cone filter instead of the stock airbox. Has anybody else thought of doing this/done it? My only fear is that I'm already running a 125 main jet with the needle as high as it goes (clip on the bottom rung), and getting a K&N filter is just going to cause me to run too lean again.

[Ariel Red Hunter]

Originally Posted by Gunrunner Doc

Just here to update. I finally installed the Mikuni carb, 125 main jet, and also performed the exhaust and airbox mods that Motocheez shows on YouTube.

My biggest mistake initially was grossly underestimating how much more airflow I was getting. I initially started out with a 115 main jet, which was great for the new carb without any exhaust mods or airbox mods. After performing the mods, the bike was just running so lean, even when I switched out the main jet for a 120. Ultimately settled on a 125, but I would have experimented with a 130 if I had one. Cold starts are definitely MUCH easier now, and I feel like I'm getting better mpg. Throttle response is much better, and I'm getting substantially better torque going up hills and getting up to speed. The new exhaust also sounds much deeper, and it's just enough more volume without being obnoxious. I don't think Motocheez explains this in his video, but the new exhaust is pretty much just the pipe. There's no packing or anything throughout, so pretty much the only thing standing between the exhaust at the headers and the open air is a 2" wide mesh screen in the muffler.

After going through this ordeal and having to remove/replace the carb so many times, I've grown fond of the idea of using a K&N universal cone filter instead of the stock airbox. Has anybody else thought of doing this/done it? My only fear is that I'm already running a 125 main jet with the needle as high as it goes (clip on the bottom rung), and getting a K&N filter is just going to cause me to run too lean again.

I wonder if your float level is correct. Did directions come on the carb box on how to check the float level? 125 main sounds about right, but normally with the needle in the middle slot. How is it picking up off idle to 1/4 throttle?...ARH

[Emerikol]

GR, I have the pod filter on my Hawk and it's just super. I didn't have to do any rejetting or other mods to the carb after I installed it. I think that the stock airbox has enough air volumetrically speaking that there isn't that much of a difference going to the pod, just easier to work on the carb is all. You will need to modify/delete the airbox to install the pod filter. Just a heads up so you know what you're getting into.

[ben2go]

Pods are ok if you're not in a lot of dusty areas or don't cross very deep water. One drop in water, and the engine will suck it up before it dies from fuel starvation.

[Gunrunner Doc]

Ariel, idle to 1/4 is pretty responsive when starting from a stop, but it hesitates a bit if I'm already rolling down the road. Carb didn't come with directions or anything, just a box and some bubble wrap.

Emerikol, have any specific recommendations for pods? A link to Amazon would be ideal.

Anybody with pods filters consider turning the airbox into extra storage?

[Ariel Red Hunter]

Originally Posted by Gunrunner Doc

Ariel, idle to 1/4 is pretty responsive when starting from a stop, but it hesitates a bit if I'm already rolling down the road. Carb didn't come with directions or anything, just a box and some bubble wrap.

Emerikol, have any specific recommendations for pods? A link to Amazon would be ideal.

Anybody with pods filters consider turning the airbox into extra storage?

OK, what model, exactly, carb do you have. Maybe I can find the float level instructions in my Mikuni book..ARH

[JustAdam]

I've got a Uni Pod filter and was wondering the same about the airbox and what to do with it. No answers yet..

[chuck]

Originally Posted by JustAdam

I've got a Uni Pod filter and was wondering the same about the airbox and what to do with it. No answers yet..

Which iridium spark plug for Hawk,the denso 5372 ix24b?
thanks

[JustAdam]

#5376 is what I used.

[chuck]

Thanks

[JustAdam]

I'm looking for a link to a set of decent LED turning signals for my Hawk. Thanks in advance.

[Merlin]

Originally Posted by JustAdam

I'm looking for a link to a set of decent LED turning signals for my Hawk. Thanks in advance.

http://www.ebay.com/itm/271929381985...%3AMEBIDX%3AIT

[JustAdam]

So does the blue light operate when the turning signal is engaged or is it on constantly as a running light?