I wanted more power too, have been REAL happy with DAX "Super Titan" (hua sheng with longer piston rod for more compression) for 10000 mile now (2nd motor, 1st one went at 7500). This is 20% more powerful than stock hua sheng, and still seems to last pretty weill, at least for me. I hammer these things.
I took the first one apart (see my post(s)) and the difference, only difference, is the piston rod. The performance started going before eventually I lost the exhaust valve. What was weird is that I was losing power, but also using less gas. Couldn't figure it out, but after if blew and I took it apart, I noticed that the plastic cam had worn circular so it wasn't lifting the valves as much. So I think it wasn't sucking gas in as much.
Anyway, on first motor, probably around 4K when I first noted decreased power, not too much. Not knowing, initially I adjusted valves, put on another clutch - at this point I think this helped, these are other things you need to do if losing power. But, with this new motor I think around 4 or 5K I will replace plastic cam. I see some places sell both the plastic cam AND the exhaust valve, so I think I am on the right track. Also, with this new motor, I am using full synthetic oil - after initial breakin I am changing it every 1K miles. This is what I did with the first one, although I was using Walmart oil. Wondering if synthetic will be easier on the plastic cam.
DAX suggested I take off the metal shroud from the engine, to increase cooling - thinking this might help longevity of my new motor. I have never put the chrome exhaust on - I am using stock exhaust. I am sure an exhaust mod, at least putting the pipe on would give me even more power. Also, using the stock exhaust, I don't think the engine cools as much, as the air is flowing agains the exhaust pipe side when I ride the bike, and it can't circulate through the fins very well as there is a sheet metal heat shield below the exterior exhaust burn protecting shield (the black cover with the vents), that prevents air flow.
REAL happy with the DAX motor, and I am NOT a salesguy for DAX ! All this being said, I also want even more power and thinking maybe I can get it out of the HF Predator 79cc after defeating the governor. My new build is the HF 79cc with the EZM clutch (expensive, but accepts potentially more different types of engines down the road). Getting a lot of the parts today. I got the HF 79cc for 87$ WITH SHIPPING INCREDIBLE. If it blows up, I just buy another one and keep it for parts.
The DAX super titan is $250 with shipping. If I was keeping with this setup (my SuperTitan ride currently is Grubee 4G trans) I would work to increase longevity of engine as described above. But, might as well do the same work with the HF - by the way I THINK (but don't know !) that the HF has a steel cam...
Have a LOT of fun !
cb
). Ill fire up my brain again and start lookin around.
