Now I own *two* DAX GT50r motors........

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Goat Herder

Gutter Rider
Apr 28, 2008
6,237
20
38
N.M.
On my latest Morini I had fun tuning the carby for high elevation. That's it all I did never adjusted anything else. It cruises great and runs like a violated Ape when I want it to.;)
 

donutguy

New Member
Feb 4, 2010
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Hi John, I got the 4 stroke motor and another friction drive unit. I'm gonna install this on my wife's bike so we can do some rides together :)
 

turbojoe

Member
Mar 30, 2011
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Little Rock,AR
I glad you were able to get your money back....What exact new engine did you buy from DAX????
John
This is more or less the same engine as the Gt50R. I'm still waiting to hear from thatsdax about the status of my engine. I guess I will have to call again to find out. It's been over a month now since I sent it back to them. I see that they no longer sell the engine so it makes me wonder what they will do if they can't fix it.
 
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FarRider

New Member
Jun 8, 2011
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Brooklyn N.Y.
I'm not trying to be argumentative here Turbo, but that engines nothing like the GT5R-
That engine you posted has been around a while, and if you look hard enough you'll notice its a horizontal mount with a reed block intake mounted "under" the crank cases.
I've seen that particular engine, usually rack mounted, with a good exp. pipe they run fairly well.
Pictured below are both sizes of GT5R engines, the 50cc and the 66cc.
As you can plainly see these are "upright" engines that lend themselves better to in frame mounting.
Note the larger timing case and the lack of a reed induction block.
FR
 

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FarRider

New Member
Jun 8, 2011
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That just sounds like alot of work....If I pay good money for a new engine,I want it to run right out of the box,with mabe some fine tuning....
John
Then buy a 50cc Honda 4 stroke (for about $250.00 more)
The china girl 2 strokes are notoriously un reliable in stock form.
I've never seen one that worked 100% right out of the box with no modifications or work needed.
When I hear comments like that, I think that person would be better off buying a ready made moped.

The tinkering is part of this sport/art/hobby, any one can just BUY a ready made bike, but working out the build, working out the flaws is what makes this so satisfying.
"I built it myself, worked out all the bugs and got it to run great"

Lets face it, what can you really expect from a Chinese copy of a 65+ year old Russian design bicycle engine that the moto bike industry latched on to?
For $180.00 for the full kit or $120 for just the engine? Your lucky it starts.
I'd like to get my hands on the Russian version.
FR
 
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mapbike

Well-Known Member
Mar 14, 2010
5,502
109
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Central Area of Texas
FarRider

You're missing a digit here friend, no one on this thread is speaking about the GT5 Grubee engines which we call HT's or China Girls, people are discusing the GT50R High Performance Engines like the one Duane at Thatsdax was selling and can be bought a hundred different palces online, it is a Modified CAG 47cc engine and Dax called his the GT50R.

You are NOT correct in what you said about the engine in the link, Turbo is right on the money.........

( I'm not trying to be argumentative here )

Peace, map




I'm not trying to be argumentative here Turbo, but that engines nothing like the GT5R-
That engine you posted has been around a while, and if you look hard enough you'll notice its a horizontal mount with a reed block intake mounted "under" the crank cases.
I've seen that particular engine, usually rack mounted, with a good exp. pipe they run fairly well.
Pictured below are both sizes of GT5R engines, the 50cc and the 66cc.
As you can plainly see these are "upright" engines that lend themselves better to in frame mounting.
Note the larger timing case and the lack of a reed induction block.
FR
 

lowracer

New Member
Oct 17, 2008
1,319
2
0
Charleston, SC
For what its worth, I have 2 of these Stage 2 Cag type pocket bike engines on 2 of my motorized bikes & although I have done a bit of tinkering with them both to solve the loosening headbolt issues, they have been running really well & start on the 1st or 2nd pull everytime. I was running a super reliable Lifan 2.5 HP 98cc 4 stroke that this little engine has replaced. Everytime I take them out, I cant help but ring the revs out them like a kid again & grinning from ear to ear. I'm guessing it @ around 4 hp & just over 50 mph. Yes, loud as h*ll with the pipe, but the perfect lightweight (~ 6lbs) powerplant for a MHPB (motorized high performance bicycle). They can also be mounted right up to any friction drive kit using the 4 clutch side holes or DIY mounted using the 5 bottom mount holes.
Priced at $125.00 without a fuel tank or exhaust pipe :)
-Lowracer-
 

cory151

Member
Oct 19, 2010
466
0
16
SoCal
If you must have a high performance 2 stroke a GP460 is the way to go.

Engine Stats: Displacement: 45.7cc. Power: 4.2+HP @11,000 RPM, 2.35 lb/ft torque @8,000 RPM. Fuel: 91 octane or higher mixed 25:1 with 2-stroke oil.

Only $255 and put in ddm code for a 5% discount

bb88xx

Quality motor that will run circles around that pocket bike motor.

What about the Morinis? 9.4hp 13,000 rpm 50cc.
 

lowracer

New Member
Oct 17, 2008
1,319
2
0
Charleston, SC
Morini's are great...just difficult to mount, very expensive.
GP460 'Run circles around'... remains to be proven?
I'll stick with my Stage 2 Pocket Bike engines over a GP460. For half the price & a broader powerband (more torque @ lower rpm's) & easier to mount on anything.
There is a reason all these pocket bike races aren't dominated by GP460 engine powered bikes?
Also there are way more aftermarket & cheap replacement parts for the pocket bike engine (Huge market).
Both engines (Pocket bike & GP460) are made in China. The most popular MB'r engine is a china girl inframe kit for a good reason...they are cheap ($$$).
Since I haven't blown up these 2 pocket bike engines yet, long term reliability seems good with 11K+ rpm engines.
$125 would be well spent for the performance you get.
-Lowracer-
 

lowracer

New Member
Oct 17, 2008
1,319
2
0
Charleston, SC
Goat Herder,
I replaced a very torquey Lifan 2.5 98cc 4 stroke engine with the Pocket bike engine & fully expected torque to be terrible, but was pleasantly surprised. I got mine geared at 15.6:1 & she pulls off the line strong. My bike weighs ~60-65 lbs & I'm 170 lbs. My 2nd bike powered by the same engine only weighs 35 lbs and I refer to it as my 'Dragster bike'. From a dead stop to 50 mph is quite an experience...lol
I know these Stage 2 engines aren't for everyone & do require attention. 2 forum members I know of had real bad results using this Stage 2 engine & a Stage 3 version & I am not trying to steer people to buy them. Dax even took his version off his website. I'm glad I bought them & I enjoy tinkering with them.
I got a jet kit coming, some more flex pipe, V-brake throttle levers, foam grips, spare gaskets (copper & paper).
Parts for Pocket bike engines are so cheap & the initial cost of these engines is also very reasonable. If I can get some good service out of them before they explode I'll have gotten my moneys worth...
-Lowracer-
 

tuk5799

New Member
Aug 31, 2010
13
0
0
TN
I also have one of the gtr50r and had no trouble at all and glad I got 1 befor he quit selling them....It has been a good motor ...i I hit about 46mph so far and more to go. with 600 plus miles on it ,its been great.
 

lowracer

New Member
Oct 17, 2008
1,319
2
0
Charleston, SC
I replaced both head gaskets (top & bottom) on both my Stage 2 Cags with nice Copper gaskets I found online for $2/ea. The stock bottom paper gaskets tend to leak & blow over a short time & are worth replacing immediately. The stock top gasket is already a nice copper one. Since making this change & replacing the stock (cheapo) chinese spark plug & plug wire with a 7mm automobile plug wire & NGK plug, both engines are running better & smoother & willing to rev silly. I'm loving these engines...
-Lowracer-
 

donutguy

New Member
Feb 4, 2010
230
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64
PA
Agreed....when these engines are running-they are sweet. All I have to do now is figure out why I am blowing clutch springs on them.
 

gera229

New Member
Sep 4, 2011
465
0
0
USA
@Donutguy
Why did you send the GT50R motors back to DAX? What was the problem/ what was wrong with them? What kept happening?
When I owned one of the 47cc pocket bike engines I always blew clutch springs. I think it's because your clutch pads are worn out - I asked Dax about this and this was his answer.

Are they blowing on the new 2 stroke engine that dax made? Is it 1 piece?
What's the difference between the old gt50r and the new gt50r?

Anyone else blowing clutch springs?
 
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