I need more power!

GoldenMotor.com

scotto-

Custom 4-Stroke Bike Builder
Jun 3, 2010
6,505
24
38
Ridin' inSane Diego, CA.
nobody has said raise compression... idk the hs motor but you should be able to deck it down a few 100ths. it will give you a big boost all over, but especially low end. here's a video on piston to valve clearance which is important when raising compression http://www.youtube.com/watch?v=KLH4muS5kWo and definitely run 91 or 93 octane after raising compression
Well unfortunately there is no way to deck the block, head or the cylinder as it is a one piece cast jug and crankcase, meaning there is nowhere you can deck it. It's not easy to raise the compression on this engine unless you can cast and/or machine custom parts for it.

dnut
 

chrisnbush

New Member
Jan 10, 2008
41
0
0
Richmond, NH
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
 

Mr. Minecraft

Visionary
Jan 13, 2012
349
0
0
San Diego
Why does Dax not make the longer rods available to buy by themselves? I would much rather buy one of those than buy an entire new engine for the 20% power gain. Im gonna call him up and see what we can figure out.
 

ocho ninja

Member
Jan 14, 2012
564
2
16
San Jose, CA
He probaly won't do it. But hey you never know.

If your looking for more power get a 79cc predator...I'm never going back after building mine. The predator provided the right power for around town without being overkill
I sold my 49cc and used the money for the new build.
 

Mr. Minecraft

Visionary
Jan 13, 2012
349
0
0
San Diego
He probaly won't do it. But hey you never know.

If your looking for more power get a 79cc predator...I'm never going back after building mine. The predator provided the right power for around town without being overkill
I sold my 49cc and used the money for the new build.
This is exactly what I have been wanting to do but I dont know where to start and where to get all the hardware. Maybe you can help me out?
 

WightBoy

Member
Aug 30, 2012
271
0
16
Michigan, USA
Pedal harder, dude, or get a motorcycle or scooter. Just my opinion, but I been on these a long time. I'm a realist and not greedy.
Well said, I am building mine for the gas mileage (and the fun of 2 wheels). If I feel the "need for speed" ill jump in my AWD turbocharged car. I think 29-30 mph is awesome for these little 49cc engines that are on bikes that were never designed for that kind of speed. On the flip side, I also think more low end would be cool. You could also regear the pedal side to accomplish that too.
 

Mr. Minecraft

Visionary
Jan 13, 2012
349
0
0
San Diego
Is it really worth it to switch to a 79cc Predator? What improvements did you notice?

Engine: $100.00
Mounting Plate: $25.00
Throttle Linkage: $12.00

What tranny and clutch do you recommend?
 

ocho ninja

Member
Jan 14, 2012
564
2
16
San Jose, CA
I thought it was. A new exaust and a different Carb like a walbron pz22 really wake up the engine
If you don't mind investing more in a good clutch, a cheetah or a dragging skin clutch work way better than the cheeper Max torque ones

And honestly its really easy make your own Jack shaft, couple of exaust clamps, steel plate, pillow blocks, a couple of spockets, and a shaft and ur all set with about half the cost of buying one.

Or you can make a transmission with thicker aluminum plate and a go cart hub carriers...

Idk there's many options on how to build one... just search them up do some reading and see which method suits ur style and budget... and build it the way you want it
 

Mr. Minecraft

Visionary
Jan 13, 2012
349
0
0
San Diego
Im looking to do it the cheapest way, while still having reliability. The other thing is I have absolutely no idea where to buy all of those parts :/
 

ocho ninja

Member
Jan 14, 2012
564
2
16
San Jose, CA
Common bro I though you were some kind of computer wiz?
I'm pretty sure you can look most of this stuff up online and either order it or find out were to get it locally.
Trust me I had no idea either, but after doing enough reading I either had all the stuff bookmarked or local address noted on were to get em from.

A lot of people post up some really helpful parts website links on this forum.
 

Dan

Staff
May 25, 2008
12,765
115
48
58
Moosylvania
Not directed at any one, but really is never a good idea to admonish any one for asking a question.

Any thing that could cause some one to feel uncomfortable to "speak", please try to avoid.