Hawk - engine break-in

[ChrisWNY]

How did you go about breaking in your Hawk 250 engine, and how long did it take before you noticed an increase in power/top end speed? So far I top out at about 50mph in 5th gear, with the 17T/45T sprockets...I have about 3 miles on the engine so far, mostly off-road, just riding around the yard with some cruising on the streets. I had no problems registering the Hawk in NY so it's 100% street legal.

I've replaced the sprockets with JT 17T/45T, swapped the carb with a Mikuni (still running the stock jet), NGK Iridium spark plug, installed the Hawk Digital cluster, drained the stock engine oil and added SAE 10W-40 for break-in (I will be running Mobil 1 syn 4T 10W-40 racing oil after I change the oil).

I have not yet swapped out the main jet (which I believe is a #98, stock in the Mikuni) for a #110 as many have done, nor have I modified the air box. I'm running the stock muffler and don't plan on changing that out any time soon. I didn't think it made sense to change out the main jet until I've put some miles on the bike...wanted to gauge how it runs and whether or not it leans out too much at higher throttle. I love the way it runs right now - it fires up in a split second (with the heat we've had in July, no choke needed!) and idles quietly with practically NO vibration except for the muffler (then again I'm used to a Harley 96 cu. in.). I'll check the valves but think I may have lucked out in that they may not need much of an adjustment...will see how things are after I put some more miles on the Hawk.

So far my experience with the Hawk has been positive...wouldn't have bought it if it weren't for all the DIY info here and on youtube.

[Hawk 229cc]

after changing from the china oil to 10 w 40 motorcycle oil before i ran it ,i just did 2 short rides around the hood let it cool down ,then went an took about 15 mile ride ,it will take about 200 miles or 5 hours then change the oil again,slow is good then a littel harder with time

Along with the mods you will notice it getting more top speed an power as the miles go by

i would not put 100% synthetic oil until after say 500 miles ,some say its too slick for the parts in these Haosen engines,but i plan to at 500 miles myself some say is the full break in opinions vary

on an off the throttle as much as possible shifting gears alot,i have 16th for the front an 45 for the rear ,also you can take the exhaust off an bore it out the cat that is ,or put an aftermarket one for about $99.00 crf 230f works fine,the bikes are starving for air ,i have not got mine done yet ,but modded the air box an got the mikuni,time has not been on my side ,true the wheels an tighten the spokes ,greace the swing arm wheel bearings & steering post an change the fork oil at some point ,,

one guy talks about the exhaust cat being like so full of crap ,how do the bikes breath,at all ,so i plan to do it to ,i may also do an air box delete ,an put an air filter on it ,i see some guys are making these bikes pretty mean ,one guy took an replaced the shocks from another bike an swing arm ,an does so pretty serious off road rideing,has compares his kawhawk to a yamaha ttr 250 r or pretty close,

[Megadan]

Change out the main jet. At least put a 105 main in it. These engines are too leanly tuned and you could potentially overheat the engine at sustained higher throttle positions. Also, you will want to also change out the pilot jet. A 25 works well for stock bikes.

As far as when they really wake up... about 500ish miles is where most of the break in is finished, but it can take up to 1000 for everything to really loosen up.

[ChrisWNY]

I ended up putting a 110 main jet into the Mikuni carb this afternoon. The VM26 carb came stock with a #100 main jet installed...it definitely seemed to run a little lean beyond 50% throttle. Hopefully the larger main jet will bring some noticeable improvement. Does the pilot jet need to be swapped out on a Mikuni VM26 or just the stock China carbs?


4-stroke engines run noticeably cooler on synthetic compared to dino oil. I used dino oil for now because there's no sense running a more expensive oil through it if it's going to be dumped after a few hours of riding.

[Sochin]

People like Megadan and myself might be excessive. But by 500 miles I think we both had done 7+ oil changes.

[Megadan]

Originally Posted by Sochin

People like Megadan and myself might be excessive. But by 500 miles I think we both had done 7+ oil changes.

I did quite a few, but I was also not very gentle with my Hawk lol. I think I did 5 or 6, with a valve check after each one. In my opinion, there should be at least 3 oil changes by 500 miles. 1. Draining the factory oil. At 200 miles, and again at 500.

[ChrisWNY]

The biggest issue I saw with the factory oil was not so much the type of oil that was in the engine (it looked like new 10W-30/40 to me), it was the amount - there was probably less than 1/2 quart of China factory oil in the engine. It would be nice if someone gave the Owner's Manual a complete re-write...it calls for 1.6 quarts of oil, from what I found (and read) that's way too much. 1 quart seems to be enough. That's another reason for frequent oil changes - the less oil a motorcycle engine holds, the more often the oil should be changed.

[JerryHawk250]

Adding an oil cooler or coolers as I've done will double the life span of the oil. The engine runs cooler and the oil stays cooler so it doesn't break down as fast. I put 1100+ miles on my last oil change and still looked good when I changed it VS the oil being black at 500 miles. One of the best mods I've installed on my hawk.

[ChrisWNY]

Do you find that shifting (especially upshifting) is a bit tricky when the engine is new/in the break-in phase? It may be the location of the shift lever in my case, not sure, but the upshift is a little stubborn at times (so is getting into neutral after a longer ride). However, I expect that this issue will subside especially after I change the oil and put the Mobil 1 syn 4T 10W-40 motorcycle oil in there (wet clutch compliant). I only have about 30 miles on the Hawk and am definitely jones'ing to do an oil change on it asap.

[JerryHawk250]

Originally Posted by ChrisWNY

Do you find that shifting (especially upshifting) is a bit tricky when the engine is new/in the break-in phase? It may be the location of the shift lever in my case, not sure, but the upshift is a little stubborn at times (so is getting into neutral after a longer ride). However, I expect that this issue will subside especially after I change the oil and put the Mobil 1 syn 4T 10W-40 motorcycle oil in there (wet clutch compliant). I only have about 30 miles on the Hawk and am definitely jones'ing to do an oil change on it asap.

Shifting gets much better after about 500 miles. I only had the neutral issue after the engine got hot but that went away after I installed the oil cooler.

[ChrisWNY]

It's easier to get the Hawk into neutral in its present state by downshifting from 2nd into neutral. Some ATV/motorcycle manual tranny's are like that though regardless of engine temp. I think it'll just take some time for the gears to mate and break-in a little. It's too bad the transmission isn't separated out from the engine, I always like using a thicker/heavier weight oil for the transmission in my Harley. Makes a big difference.

[Megadan]

Most bikes have the transmission integrated with the engine. It makes for a much more compact design. The transmission is designed around the idea of using lighter motor oils.

In the case of these engines, it is just the nature of the design, and the cheap nature of manufacture. Every Honda I have owned has had a smooth and easy transmission. My last Hawk was actually very easy to shift and find neutral after putting miles on it.

As Jerry hinted at with his oil cooler comment, a big part of the way these shift has to do with the clutch - either the oil condition or temperature. As they get hot, the clutch engagement changes, and I often found I needed to adjust the clutch a little bit once the bike was up to temp. Really easy to do at the lever adjuster by just giving it a turn or two out.