2007 Kangchao "Monster" 250

[ripcuda]

My latest "project"...

2007 Kangchao "250cc" ATV
- 230cc watercooled 167MM engine
- manual clutch 4-speed w/ reverse [R-N-1-2-3-4]
- shaft-drive 2x4
- looks like a close copy of a ~99-ish Yamaha Bear Tracker

Story was a friend who borrowed attempted to jump start it off a car and smoked something electrical. The previous owner then attempted to do some homemade rewiring to get it going and left a hacked up harness. I was given a bag with the $20 electrical set (coil, volt reg, starter solenoid, missing cdi) he'd bought in his repair attempt. But I quickly realized that the volt-regulator was the wrong type and I'm betting the CDI that came with the set was an AC CDI... and this ATV uses a DC CDI. That would explain why he didn't give me the new CDI... probably smoked it too during his rewiring. Oh well... probably why he sold it so cheap!

So I have a fun rewire project ahead. I've purchased a new ATV wiring harness and a new DC CDI. I'm hoping my 12-pole, 3-phase, 5-wire stator and 6-wire regulator are okay... but even if not... they are available for not too much $$.

Mechanically, it appears to be in decent condition. No rust, clean and straight frame... just rough in the plastics department. I'll clean those and repaint them... but they're never going to be beautiful. Still... I'm pretty excited to find this utility-style ATV. Will make a fine jet ski trailer mover around the yard!

















Cheers!

[ripcuda]

My Google-foo hasn't turned up much for the Kangchao. But I have found a few older sites showing this "Monster" back when it was for sale. ~$2600 sale price

http://www.lowestpriceatv.com/monste.../atv-250cc.htm

http://www.txpowersports.com/roketa_.../atv-250cc.htm





This is what mine must of looked like originally... not too shabby.

Stats from the web: (converted some of the metric #)

• Engine:
  
  
  • Cooling: water cooled
  • Max horsepower: *13.4hp / 7,500rpm
  • Max torque: *11ft-lbs/5,500rpm
  • Bore*stroke: *63.5 x 62.2mm (8.7:1 compression)
  • Max speed: *≥34mph
  • Climbing ability: *≥25°
  • Ignition: C.D.I
  • Starting system: Electric
  • Battery: *12V, 14Ah
  • Engine oil: *1.3L (10w-40)
  • Gear oil: *0.25L
  CHASSIS ETC.:
  
  • Transmission: manual
  • Driveline: Shaft
  • Driving wheel: 2wd
  • Suspension,front/rear: *single arm-swing/integral
  • Brakes,front/rear: * drum/drum
  • Tires,front/rear: *23 x 7-10/22 x 10-10
  • Fuel capacity/type: *2.35 gal
  • Weight,G.W./N.W.: *661lbs/507lbs
  • Max load: *365lbs
  DIMENSIONS:
  
  • Wheelbase: *1,160mm
  • OA L*W*H: *1,850 x 1,030 x 1,130mm
  • Height to seat: *820mm
  • Min ground clearance: *155mm
  • Carton size: *1,970 x 1,110 x 880mm

Pretty cool

[ripcuda]

I checked all the fluids... clean and full... nice for a "beater".

I set the valve clearances, .002" intake, .003" exhaust... intake was a tad loose, exhaust was spot on.

Removed the EGR valve and components. Crimped and soldered the exhaust outlet pipe off the engine (in lieu of a nicer block-off plate).

I've tested the stock DC CDI... and could not get any spark... got a new one coming.

Ordered a new ATV wiring harness... hope it has all the correct plugs and wires needed... and that the colors maybe match one of the wiring diagrams I found.

It's got the same '07-ish (no tamper-proof screws) Keihin-clone PZ30 carb on it that my Runmaster does. Which is sweet, since I still have jets left over from dialing that one in. Carb is in nice shape. I did have to buy a new intake manifold elbow... the rubber was torn on the original. I've decided to ditch the crappy airbox setup and go with a pod filter. (I won't be fording any water crossings or anything). I'll jet the carb accordingly.

Being a no-title, no-paperwork project... can someone direct me to where I could find the VIN on this? I've looked all over the frame and can't seem to find any stamped numbers (besides on the engine).

Cheers!

[Adjuster]

Very cool. Hope you get it going.




/

[ripcuda]

Got my new DC CDI in tonight. I hooked it up to my scabbed together test wiring to see if it would spark. And it did!

So I color traced all the wires I used on my wiring diagram to show the minimum wires needed to test spark at the plug.

-red is power line... direct to cdi (no kill switches)... and also to starter for cranking engine
-greens are ground... they all lead or connect back to battery negative.
-blue is trigger signal out of magneto... it goes direct to CDI
-black is coil trigger line out of cdi... it goes direct to coil

I pulled the spark plug out of the engine and had it in the spark plug cap... just laying on the engine to ground so I could see the spark when I cranked the engine over

To get the engine to crank (w/o a button)... I just shorted my starter ground wire (also grounds the whole engine) to the battery and it cranks until I remove the wire off the battery terminal.

With this minimal wiring on my DC cdi... I was getting nice, fat, blue spark as the engine turned over.

Now... just waiting on the new wiring harness and the fun of making it fit and work.

Cheers!

[humanbeing]

Originally Posted by ripcuda

-red is power line... direct to cdi (no kill switches)...

For temp test is OK... Normal practice is bonded to black wire (ie. can be s/w OFF!!!)

[ripcuda]

Agreed. This was only for a temporary test to crank the engine via the starter to see if it had spark.

I would not attempt to run the engine without a kill switch and a starter relay (w/ switch). On my setup with a DC cdi... the power to the cdi goes from the battery through the start-stop (kill) switch and then to the cdi (different color wire). So removing power to the cdi stops ignition (spark) and the engine.

Cheers!

[Weldangrind]

I have a very similar motor sitting on the floor, except mine is chain drive. Your pics are guiding me on how to plumb it.

[ripcuda]

Well... got to work on the wiring harness this weekend. The new one I ordered... sadly... was too different from my original. Half the connectors were different... many wire colors were different (not that I couldn't handle that... just lots more to trace and figure)... and it seemed as though it was designed for a machine with the CDI and regulator more towards the front of the craft... not in the rear like on my ATV. Maybe I had it backwards!

Either way... I decided to go back to the original and fix it. I removed all the etape and wrappings. Inspected all the wires. Soldered all the crimped junctions. Fixed the previous hacking. Replaced a few broken connectors (used good ones off new harness... since I'm not going to be mailing it back to China). Next, I laid it out on the ATV and double checked all connections, lengths, etc.. Then wrapped it all up once again and put the protective plastic conduit on it. Back on the ATV... into place... all connected up.



Happy to report everything is working (that I can test... no lights currently). Key switch, kill switch, starter button, brake switch... all working as expected. Engine turns over and makes great spark!

I also thoroughly went through the PZ30 carb. Looks like the stock jets were a #98 main... and #38 pilot. Based on my PZ30 tweaking on my Kinroad... I decided to open the pilot up to a #40... since they always seem too lean down low from the factory. Then I used a spare main jet ~#102+ as a starting point.

Got the carb all installed... and was excited to hear this engine finally sputter to life. But that was not meant to be. Turns out I have zero compression. D'oh!

So... next up will be to pull the valve cover... make sure I didn't botch something in there when I adjusted the valves earlier. Would be nice if that were the case... but I'm not holding my breath.

If not valves... guess I'll be pulling the head off to inspect. Easy enough to get to... won't even have to pull the engine out of the frame on this ATV. Hope the head is okay... and it's nothing more than just rings. Guess we'll see.

Cheers!

[ripcuda]

Well... got the valve cover pulled and checked my clearances. Still fine... so I loosened them both up to be "tappy"... but that still made no difference. I can hold my thumb over the spark plug hole while cranking and there is not enough compression to push it off. Darn.

So started pulling the head... and another darn! The head sits on studs/guides... and as such can't clear the rear head engine mount. So gonna have to try to undo front engine mounts and tip it forward an inch to get the head off. If that doesn't work... guess I'll have to try and disconnect the shaft-drive part bolted to the engine to be able to remove the engine.

Still not sure of the issue... as I lifted the head and inch... I saw what looked like a big dimple in the middle of the piston... but couldn't see it clearly. Leaned out a hole in it?? We'll see soon enough.

Cheers!

[Weldangrind]

If it does have a hole, you could use this opportunity to build a larger displacement motor. You can find cylinders and pistons that feed 250 and beyond on Taobao. You might have to open up the case mouth to accept a larger cylinder.

[humanbeing]

Loncin had 70mm version
Anyway WYSiWYG https://mydlm.taobao.com/category-1246973655.htm Lifan, Zongshen ...had minor difference (different direction...)

[ripcuda]

Wow... a 300cc kit. That would be pretty cool. But I'm going the more affordable route on this project for now. Just keeping it as is.

So, thankfully, I was able to unbolt the forward engine cradle and rock it forward and inch or so. This let me pull the head and cylinder off. Well, I'll be. There be a hole in my piston!



So I pulled the cylinder off and removed the piston. Cylinder looks fine with no scaring or issues. So I measured up the piston and cylinder triplely and bought a new piston/rings and gaskets. 67mm diameter.



Thankfully the piston hole was tiny... so doesn't appear to be much debris blown into the lower case. Rod feels good and proper... and crank feels smooth and all. So, hopefully all will be fine. As soon as I get it running... I'll be changing the oil.

So I'm used to hole'ing a piston in all the 2-stroke engines I play with (jet skis)... but seems odd for a 4-stroke. It did have a torn rubber carb intake manifold. Could have been a bad enough air leak to run VERY lean. Well... I fixed that too.

Now to await for parts. Cheers!

[BlackBike]

Man, perfect timing!

[ripcuda]

Got the parts. 67mm piston/rings kit + gasket set + exhaust crush gasket. Happy to report the 67mm piston fits perfectly and the included piston rings come gapped perfectly too. And the gasket set has all the ones I need. Score!

So I got all the mating surfaces cleaned, degreased and ready to go. Then indexed all my piston rings and put the piston on the rod. Next I lowered the cylinder (honed and cleaned) over the piston and into position. Had to lift cylinder back off to get one of the cam followers into proper position... but easy enough. Then came the head and torqued it all down. Put in the push rods and valve assembly next. Set valve clearances once again (.002" in, .003" ex) and buttoned up the valve cover. Rocked the engine back into position and reattached all the mounts. I replaced the stator side cover gasket (was torn)... and greased up all the starter gears... and buttoned that side cover back on. Carb/intake were next. Exhaust header w/ new crush gasket was after that. Lastly I re-attached all the cooling system hoses and topped off the radiator with new coolant. Then it was time.

I hooked up the battery and primed the carb with my spray bottle of premix. And it fired to life! That was the first time I ever heard it run! Now it was time to put the gas tank back on. Cleaned out the tank... tested the petcock and reinstalled with a new fuel line. One more carb priming and it started and ran! Sa-weet!

Played with the carb idle air mix screw and got it set. Feels like the pilot jet and screw are set pretty well on the bottom end so far. Next up was to see if the clutch worked and any of the gears worked. Happy to report clutch is fine and reverse plus 4 forward gears are all working properly!

Rode the "Monster" around the yard without a seat... haha. Fun little rig. I gave the engine 3 good heat/cool-down cycles... and kept the RPMs varied. Feels good... very good engine braking going down a hill. Does feel like I'm too lean up higher in the RPMs. Will have to dial that in once I get it all back together.

Next up is pulling the wheels off and servicing the brakes. Then time for bodywork and reassembly.

Cheers!