250cc Hawk Modifications (The Necessities)

Gunrunner Doc · 01-27-2017, 02:14 PM

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.