250 hawk enduro performance

[k4fireblade]

With the 17 tooth it still topped out at 60 but it was straining to do it if I went up hill a lil bit it would loose speed. But it still took off from a dead stop easily. The engine seems to make good low end torque but lacks high rpm hp. With the 16 tooth it cruises 50 very easily but still only tops out at 60-62 mph. The engine isn't red line in fifth gear. Just lacks the hp to go any faster. And it's getting 75-80 mpg I weigh 170 lbs. Its a very nice bike for the price. But a speed demon it is not. Lol. Befor changing carb and sprocket my bike would only top out at 55 mph. And sounded like it revving very high. Now it's very comfortable at 55

[CorryWanSprocket]

Hi guys (and grrls, if you're reading this).

I too have a Hawk. I bought it at the end of October through APSCUSA and have about 300 miles on it (I have a 2013 Wee Strom that I tend to ride more).

Like many others who own Hawks, I've replaced the stock carb with a Mikuni 30mm clone. I'm about 400 feet above sea level and running size 112.5 main and 35 idle jets.

Although I get a lot more punch with tihe better jetting, one thing I miss about the stock carb is that it has a knurled idle screw. The eBay "clone of a clone) has a different diameter idle screw that has a phillips head. Because the bike takes a long time to warm up I have to carry a screwdriver to adjust the idle between "cold" and "warm". I *should* be able to use the top adjuster on the throttle cable to increase the idle speed. The cable itself is a bit too long for the housing for this application, though, so even at maximun extension I don't get enough increase in idle speed. I asked the eBay seller that I bought the carb from (motor99motor) if they sell knurled screws, or if they know which Japanese carb make and model has the same idle screw diameter/thread as the one they sell. All I got was meaningless replies like "We don't sell knurled screws (end of message). Or "The carb is a Mikuni" (end of message).

So I'm going to buy a couple of throttle cables (e.g. XR100, XR185, XR200) to take up the slack (and adjust idle from the there) and return whichever cables don't fit.

Another common mod that I made was to swap out the front sprocket for the JR 17 tooth. I weigh 225 lbs and consider it reasonable that it loses a bit of speed up hill. I'll take k4fireblade's advice, though, and try out the 16 tooth sprocket. Before I do that, though, I'm going to re-install the stock 15 tooth sprocket. I recently noticed that the outermost knobs of the very aggressive rear tire are hitting the drive chain. When I go around corners I can clearly hear (and feel, at low speeds) the chain slapping as it gets whacked by the tire's knobs. This is also stretching the chain; it's getting bent sideways each time the tire's knob "pushes it out of the way". As at least one person on ChinaRiders has pointed out, a 428 chain isn't necessarily the best choice for a bike this size...

So I sat the bike on a paddock stand and saw that there's almost zero clearance between the chain and those outermost tire knobs. I can probably slip a piece card stock in between them, but nothing else.
If I get the same interference between chain and tire with the "stock" front sprocket I'll look into placing some spacers behind both sprockets and move the chain line further away from the rear tire. The trouble with that idea is that I might start grinding through the front sprocket cover )-:

Most likely I'll use a bread knife (which works wonders on rubber and foam), or my Tread Doctor (which needs constant sharpening to make it cut rubber like warm butter). Either way, I'll cut off enough of those outer knobs to prevent them from hitting the chain.

Other mods that I've made to the bike are:
1) Generic Stomper footpegs made for XR100
2) RAM mount "Double Take" Enduro mirrors. These are fantastic but I choose to remove them whenever I'm away from the bike for any period of time (lest someone else do the same).
3) Battery Tender / Deltran BTL14A240C battery (the stock battery would not hold a charge).
4) Pro-Grip silicone handlebar grips. These are cheap ad do a great job of soaking up handlebar vibration.
5) Garmin Etrex 30 with RAM mount. Among other things, this has shown me that the faster I go on the bike, the more inaccurate the stock speedo is. It's pretty dead-on when it says 25 MPH. But when it says 65 MPH (down hill with a tail wind :-), in reality I'm only doing about 53 .
6) Closed the gap between the forks that hold the side stand in place. The was so much slop that the bike would tip over unless I put a piece of 2x4 underneath the kickstand foot. Closing the gap helps a bit, but the bike still leans over way too much for comfort.
7) Disabled the extremely annoying beeper inside the turn signal relay.
8) Removed all throw from the rear master cylinder. This allows me to cover the brake pedal with my right foot rather than rest my foot along side the pedal.
9) Replaced the stock shift lever with one (from eBay) that fits a CB350.
10) Cut the headlight ajustment spring in half so I could raise the beam to a decent height.
Anyone who is excited about the fuel gauge on the dashboard should know that the fuel gauge is about as accurate as the speedo. It reads 1/2 tank when the tank is actually 3/4 full. Because of this, when I install the Trail Tech I'll probably pull the entire cluster off the bike.

Planned mods:
1) Rear shock. It feels a lot like a hard tail, even under my 225 lbs.
2) Train Tech Vapor speedo/tach. More accurate than the stock speedo, and I can get rid of the stock sppedo cable that for some reason keeps jumping out of it's wire fork guide.
3) Make the stand adjustable by cutting it about 2/3 of the way down, brazing some threaded anchors inside, then using threaded rod and locking nuts to adjust the length. That is, unless someone knows of a longer stand that will bolt on.
4) Swap out stock levers for shorties.
5) Bark busters and hand guards.
6) Install a louder horn (Wolo).
7) Combination smoke screen/oil slick so I can teach tail-gators a lesson. Actually, I'm told that dropping a 1/2" ball bearing will do the trick. Make a loud racket when it bounces up and down underneath somene's oil pan :-0

Yes, this is a long post. Hopefully it helps someone either figure out a problem or decide whether or not the Hawk is for them.

Peace.

[Zorge]

You can do some shortening and soldering of a cable end, instead of finding one that fits or fabricate new, longer adjuster on a carb cap.

Did you try to fit different idle jet?

I believe that this collisions of chain and tires can be avoided if you fit some spring loaded chain tensioner. Of course, new, decent quality chain would be nice.

I would prefer knob trimming over sprocket spacers - IMO it is simpler way to solve the problem.

You don't need to kill this beeper of yours. I think that piece of duct tape will hush lil' bastard.

Is it possible jut to alter angle of kickstand, to bend him closer to the bike and avoid tipping?

[CorryWanSprocket]

Thanks for the reply, Zorge!

I've never had luck soldering ends on cables, but the idea of adding a spacer to the carb-end of the cable sounds like a great idea.

That's a brilliant idea to increase the size of the pilot/idle jet. Thinking through the effects of jet sizes, needle position, etc. is not one of my strong points )-:

Thanks for leaning me more in the direction of trimming the tire. That can be one of my winter projects.

Installing an automatic cancelling device for the turn signals would be a better idea than any beeper, IMO. I really liked the one on my 1979 Yamaha XS650 Special. As I recall, the device automatically cancelled the turn signal after 50 meters. I've though about how to replicate that functionality (Raspberry Pi, Trail Tech speedometer, custom relay). Too much effort for me. When I install the Vapor I'll upgrade to the Trail Tech dashboard and make sure that the telltale light for the indicators is REALLY BRIGHT (enough to get my attention even on the worst of foggy brain days).

Regarding the side stand, I have thought about bending the side stand mount (where it is welded to the frame), but that would stress the frame. I suppose that I could heat the weld, but I'm concerned that I would either:
Cause the joint to be too ductile. If that were the case the mount would eventually bend at an even worse angle. I'm 5'6"/168cm tall and need to stand on the foot pegs to kick start the bike. Adding a longer stand (say, from a DR-Z400) might work, but having an adjustable stand (like the "Soupy's" on my Wee-Strom) would allow me to change the rear shock preload (once I buy and install such a shock - the stock rear shock has no adjustments).

Thanks again for your reply. Didactic processes help engineer better solutions.

[Zorge]

Don't thank me. I'm, like most of guys here, some sort of (keen) weekend mechanic who can afford to deal with simple machines like those Chinese motorcycles, plus, I'm trying to improve my awful English.

Soldering gun is mystery to me too. I believe that he and I have some bad karma between us.

Carb tuning is no-one's strong point! Luckily, someone determined what you must to get as a result and basic rules on how to do that, so.... let "didactic process" to go wild.

Idle is (on theory, at least) job for the idle jet. Needle takes control later. I saw that you can buy on, for example, "Aliexpress", for not than more 15-20 bucks a handful of different size (and type) jets. And again, as I written recently, by my experience, spring/summer/autumn and winter carb settings are two different things. I'm not even trying to find all-season setup.

About sprocket spacers vs. tire trimming: I just make a choice what is more feasible. OK, spacer on rear sprockets is thing you can fit easily, but what to do with the front sprocket? I have some idea how this thing can be done, but is too much machining for my taste. Some tire trimming or even fitting a new, narrower one is even cheaper and less time consuming. Plus, stock tire wouldn't last more than three years. Tops!

I mentioned chain tensioners. Those tensioners are somewhat cumbersome, but they seems to do the job. I believe that, even with current chain and tires, you would feel improvement.

When I mentioned bending, it was not anything about the frame, but about the kickstand. At least, this piece of pipe is not high-tech, so you can modify damn thing as much as you want or, if anything else doesn't help, even make new one. Regarding adjustable length kickstand, what you have in mind? To make telescopic kickstand with half dozen holes/lengths or something else, like using threaded rod and coupler for this contraption?

[CorryWanSprocket]

Your English is very good, Zorge. Better than many U.S. citizens IMO.

Bending the kickstand at an angle closer to the bike would cause it to strike the swingarm when retracted. There are at lesdt one post on either ChinaRiders or ADVRider (maybe both) that show the mod that I had in mind (see my earlier post above). Using a design similar to telescopic walking cane is a brilliant idea, though. I'll post photos of whichever method I get to work.

Thanks again.