I wrote up a valve adjustment procedure a few years ago, maybe it'll help you.
link:
http://www.motoredbikes.com/showthread.php?38514-How-to-adjust-your-GXH50-Huasheng-Titan-valves
I'll try answering your questions the best I can. You put a lot of them in your post!
Thanks a bunch! Much appreciated! Is the valve adjustment needed because of poor manufacturing processes? Are they that far out of whack 'out of the box'? I'll make the adjustment.
I appreciate hearing 'how it is' with regard to the various components out there, regardless of whether I own one or not. I'd like to find what works best, not the cheapest... but what's worth the investment, and what's not.
The Huasheng is made in China by usually underpaid folks who may or may not take pride in their work, and that attitude may or may not change depending on what day of the week it is. Sounds like anywhere else, no? Anyway, valves being out of adjustment significantly alters the performance of an engine, especially one this small. Doesn't matter where it's made, best to make sure things are set right if you know the specs. Call it an enthusiastic doublecheck.
The one thing I found a little disappointing about the 7G transfer case was the excessive drag when pedaling. I expected some, but not that much. I did add an upgraded spring tensioner (415# Chain) and have a 10t idler gear ordered. The spring that came with the tensioner was extremely weak for the job so I added a 30lb spring. Now tension is perfect as I go from throttle-on to engine-coasting to throttle-on. The idler gear should help too. I also just received some 1/2" vibration isolators sized to M6 1.0 for the engine mounts. We'll see how that works. This is all in an effort to minimize vibration and noise.
This is to be expected when there is no freewheel mechanism on the transmission output. Pedaling with the engine off will turn the whole belt assembly and thus the freewheeling action is at the clutch drum. I don't know of a freewheel for the 7G's output shaft, but a lack of a freewheel gives you engine braking ability. Most Grubee 4G have freewheeling action and thus lack any engine braking.
If you want to minimize vibration, use a quality mount and make sure it's tight. Rubber mounts will often exacerbate any vibration.
A single cylinder engine is by nature unbalanced harmonically, so there will always be some NVH somewhere.
I pretty much trashed everything that came with the kit opting for the best stuff I could find. I bought the Harmony Adapter Kit with 48T sprocket, which bolt directly to the hub via the 6 disc-rotor bolts (vs. clamping to the spokes). It works great. Love it! Should I change to a 41# chain?
If your chain run is perfectly straight, a standard BMX-sized 410 should work. If you want a little peace of mind, use heavy duty 410 like KMC's 710.
If you want even more peace of mind, use 415, which is a little wider (3/16" vs 1/8"). #41 will also work, but IMHO is unnecessary.
You will get better performance with a lighter chain.
BikeBerry is getting ready to release a flexible Poo Poo exhaust with a flange for the HS 142F. Not sure if it will have the expansion chamber like the two stroke version. I want a pipe that takes the noise/pop and puts it behind the bike, and muffled as best possible (even at the sacrifice of a little power). That means a longer pipe.
It shouldn't have the expansion chamber. From my experience, BikeBerry is a joke for 4-stroke stuff. They don't seem to know what they are doing.
Get the Whizzer flexpipe from Memory Lane Classics for $22 and their tailpipe tip if you like. If you want a snarly muffled sound, use a large Briggs cigar muffler.
They are <$10 at Ace Hardware. On my setup I don't use a muffler anymore, I just bend the end of the flexpipe slightly downward.
As for the stock air-filter... I've seen some folks recommend taking out the sponge and running nothing? Is there something better out there or do I have to engineer a solution myself?
Keep the sponge, but drill a bunch of 1/2" holes in the air filter cover. It will work just fine. You can upgrade the filter to something better.
It may not win anything in the looks department, but it will work just fine. Or you can change the whole intake and carb and use Venice Motor Bike's kit.
His kit will eliminate any problems you will likely end up having with the stock carburetor, and it also will improve performance a bit.
The last two questions are the most important to me...
Will I appreciate the difference and benefits of the EZ Q-Matic transfer case? Subjective question... I suppose? Is it smoother, quieter, and easier to pedal 'engine-off'?
Is the Honda GSX50 engine worth the additional money over the HS 142F? Honda is unquestionably the pinnacle of quality precision manufacturing processes, but does that transfer to the GSX50? The engine designs in photos look so similar, one can't help but think they're all the same... a horse apiece. Question is... is the Honda quality there?
Thanks again guys! You comments are really helpful!
Cheers,
Ken
The Q-Matic is an excellent cruising system. It's is smoother, about as loud and about the same difficulty in pedaling with the engine off.
It's much slower on take-off from a dead stop than a 4G/7G and doesn't like slow cruising speed (clutch can burn up prematurely).
But on the straights, it's perhaps the best system. You can blip the throttle all you like and the system is easy on the bike.
The GXH50 is not worth the extra money over the Huasheng. All said and done, the GXH50 costs over twice as much, it's only slightly better in the end.
It does have very slightly more power (~5-10%) and it's a little quieter. It also comes with a governor and low oil shutoff, which get in the way.
It will not necessarily last longer than a Huasheng. Either engine can break when over-revved for extended periods. Primitive oiling system.
My brother has had a GXH50 and Q-matic for over 5 years. He's had to rebuild his engine once already, has about 2K miles on his setup. He runs hard.
I've had a Huasheng and a 4G on SBP shift kit for 5 years. I'm approaching 10K miles and my engine still starts in 3 pulls or less and runs like new.
I use 15w40 Rotella T oil and every 2 tanks of gas, I put a capful of Marvel in the gas as an upper cylinder lube.
Change oil every 2-4 months, adjust valves the same time, don't rev it over 7500. Change fuel filter every 8-10 months.
It should last you a long time.
