HuaSheng 142F vs Honda GXH50 vs Dax XC50s

[MotorBicycleRacing]

Well I ripped down my old 142-F and have the piston out of it.

I am planning to do a post mortem on the Super Titan soon (for parts), when I have the piston I can do a side by side pic.

The 142-F died when racing a bicyclist. Didn't totally die - i.e. wasn't siezed up. Piston still moved fine in the cylinder, but the crank clamp was loose, the screws were loose. Probably damaged somehow, but is it possible the screws come loose on these things, could this be one cause of death and so possibly be avoided ?

I am looking forward to seeing the pics.

My rather biased guess is that there is no difference and the
super titan doesn't make 3 hp or any more hp than a huasheng.

 

[Quenton Guenther]

Hi Chrisnbush,

The Q-Matic has been installed on a wide variety of motors, including a B & S Vanguard 28 HP motors. As long as the side of the motor has a flat surface and a crankshaft sticking out the side at least 2" the Q-Matic should work. The Q-Matic offers both "free-wheel" action and motor braking. As long as the 6 clutch shoes are enguaged the throttle can aid in slowing down the motorbike and is much easier on the bicycle brakes in the process. When the bicycle slows to approx. 15 MPH the clutch will dis-enguage and allow it to freewheel. The special Max-Torque clutch offers a different method of clutch action as it has 3 stages of operation. Stage one is idle and the clutch isn't enguaged. Stage two is the "ticking" stage where the clutch start to enguage and gradually slides into lock, and the third stage is total lock. The majority of clutches currently used by most companies on the 4 stroke motor is either dis-enguaged or enguaged with very little "ticking", which means the clutch slams into lock and doesn't allow the smooth transistion to lock. If the clutch quickly goes to lock, it requires a more radical ratio to overcome the harsh enguagement. The Max-Torque clutch allows us to make the ratio better for cruising, approx 6,000 RPMs at 30 MPH, not 9000 RPMs at 28 MPH as do many other drive system. Running the HS or Honda 49 CC 4-stoke at 9000 RPMs for an extended time will cause the rod to pull loose from the crankshaft.

We will gladly help anyone fit our drive to alternate motors, as we have a small machine shop and can fabricate many parts if needed.

Have fun,

 

[Scootmeister]

Quenton, how do you deal with tapered shafts like the Honda or stepped shafts that are prevalent on B&S motors designed for electric generators? Does Max Torque offer mounting collars that fit these applications or do you have to machine an adapter?

 

[MotorBicycleRacing]

Quenton, how do you deal with tapered shafts like the Honda or stepped shafts that are prevalent on B&S motors designed for electric generators? Does Max Torque offer mounting collars that fit these applications or do you have to machine an adapter?

The Max Torque clutch does not install on the motor shaft on a Q Matic.

If you can install a ~ 2" V pulley on the motor shaft and have a flat area
to bolt the Q Matic on it will work.

 

[Quenton Guenther]

We fabricate the adapters for various 4 stroke motors. We also configure the clutch to work with different 4-stroke motors as often the primary ratio is different. As an example the 79 and 99 CC Harbor Freight require a larger primary pulley to take advantage of the lower RPM range and more torque. We can set up the primary to offer final ranges from 16 X 1 [approx.] to as low as 7.5 X 1 [approx.] with different primary, secondary, and belt options. We just contracted one of our vendors to make a special 3 piece optional internal bearing carrier to make changing ratios and belts much easier and faster.

Have fun,

 

[chrisnbush]

Hi Chris. Looking forward to the side-by-side of the two pistons. Then we will know for sure if the Titan piston is domed. On your HS, when you refer to the crank clamp do you mean the bolts on the lower end of the connecting rod. If so, that's what Quenton and others were saying about these things coming unglued at high rpms. If you had the engine wound out tight when she blew that's probably what happened. Otherwise, it could be another example of a quality control mishap where your particular engine got through the production process without the rod bolts properly torqued. On a lot of engines, the connecting rod bolts have washers with tabs on them that are bent against the bolt head once they are torqued to prevent them from backing out. Maybe you can post pictures of the damage for a better post mortem.

Well I broke down my Super titan that blew with 7440 miles on it, quite instructive. I have attached some photos.

Of particular interest are the plastic cam gear photos. I have the Super Titan cam on the left, with my original 142F Hua sheng cam which blew at around 3500 miles on the right (I think this on this one the bolts clamping the rod to the crank came loose, note that there is NO locking washer on the bolts, they are just torqued). The super titan cam is worn almost circular, compared to the 142F. Both have some gouging in the plastic, where the rocker contacts the cam surface, but the super titan wear is extreme.

This makes some sense, as I was losing power, and getting better gas mileage, a weird phenomenom I thought. If the cam becomes worn almost circular, regardless of how well you adjust the top rockers, the carb valve isn't going to lift very much in a cycle, probably preventing a full charge of vapor getting in. Might partly explain my loss of compression, if I am not getting a full volume of vapor in to compress. Certainly would explain a loss of power.

Thinking Hua Sheng should put metal cam gears in these, maybe should put them in a new motor if you can find one the same - are the GXH50 cam gears plastic ? Maybe get the Honda part, and replace the Hua Sheng right out of the box.

Anyway, the other photo I have is of the super titan piston (left), and 142F piston (right). It is simply the fact that the rods are different. The one in the Super Titan is marked "2", the one in the 142F is marked "3". You really can't tell in the photo, but when I carefully line up the rods, the super titan rod looks to be just about 5mm longer, enough to cause the increase in compression. End of story, I think.

It looks like the cause of the catastrophic engine failure (why it blew) was actually a broken valve (exhaust). I can see where it hit the piston and caused it to stop. I THINK if I were to replace the valve and the cam gear, this thing would run again. Kind of tempted to try it, to see how much power the thing still has.

I will do another post of the dissassembly sequence of the cam gear, valve lifters. Anyone ever put these back together ? If so, how in the HECK do you get the timing spot on the cam gear to match that on the crank gear will pushing the clutch side part of the crankcase back on to the main crank case piece ? Seems like it would be impossible... Any ideas ?

Wow what a lot of fun that was...

 

[chrisnbush]

By the way, the wrist pin bearings and the shaft clamp seemed fine on the blown Super
Titan. My feeling now is that there is not any increased wear due to the higher compression of the Super Titan, at least nothing that contributed to the failure. The exhaust valve, being slammed closed by the spring, and probably getting heated and cooled the quickest of most everything in the motor, seems to be what failed.

What I would do if I sold these things would be to replace the plastic cam gear and valvies with GHX Honda parts, I am assuming they are sourced better ;-)

 

[chrisnbush]

Here is dissasembly sequence for cam gear and valve rockers. To keep things from scattering when you crack the case, best to crack the clutch side case first with clutch side up, but then dissassemble with clutch side down. Sequence showing the clutch side casing first, and then the other "half" (where the valve rockers stayed on dissassembly).

OOPS valve rocker sequence is first...

enjoy

 

[chrisnbush]

One more thing, found this really good diagram on Honda GXH50 disassembly (and reassembly !) which is pretty much the same as the Hua Sheng 142-F. Has torque values, etc. Some interesting differences, the little collar piece was on the plastic cam gear, not on the valve rockers in the 142-F when I took it apart. Also, obviously, Hua Sheng doesn't have low oil alert. Thought I would post it here.

 

[BigBlue]

chrisnbush,

thanks for the assembly diagram! Where did you get it from?

Chris
AKA: BigBlue