Anyone tried this wider port China Girl Motor?

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maurtis

maurtis

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Dec 14, 2011
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Kyle, TX
Re: Anyone tried this wider port China Girl?

If that picture is from the RB80 kit, that intake is not the one that comes with it. I wish it did since it looks interesting, though!

My RB80 kit came with an aluminum intake manifold that looks like the regular steel one but was port matched on the cylinder side already. Nice to not have to port match it myself, though.

I am still contemplating going with a MM-style billet intake and DAX RT... some day...
 
dragray

dragray

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Re: Anyone tried this wider port China Girl?

that's how my 49 cc is...no intake manifold.
the carb is bolted right to the cylinder with some long studs with nuts on the ends.
this carb is totally different than the standard nt carb, and it's a 13 mm.
this carb can be found on china made 4 quads, pit bikes and pocket bikes.
the carb itself works great but i think it's a tad too small. it's also a pita to get the carb off to re-jet, adjust the float, etc.
on the up side, this set up is excellent for 20" frames (which is what mine is) because the lack of an intake manifold, frees up room for clearance between the air filter and the seat post tube.
 
MotorBicycleRacing

MotorBicycleRacing

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Re: Anyone tried this wider port China Girl?

Nashville Kat said:
I saw this in a kit at boygofast yesterday, and wondering if the wider intake port here is any good?

Do you think this will be a future trend, and we'll see the kits change to this?
Click to expand...
As dragray said that motor is a 50cc
They have been sold for quite a while.
I had a few of the Grubee labeled version of this motor over 3 years ago.

The intake port is rectangular and is a bit bigger than a round head 50 but
the motors didn't run that great mainly because the pocket bike carb is on
the small side and the heat from the motor would affect the carb.
 
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mapbike

mapbike

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Mar 14, 2010
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Re: Anyone tried this wider port China Girl?

Replace the studs with bolts and the carburetor should be easier to remove for cleaning or re-jetting.

Peace, Map





dragray said:
that's how my 49 cc is...no intake manifold.
the carb is bolted right to the cylinder with some long studs with nuts on the ends.
this carb is totally different than the standard nt carb, and it's a 13 mm.
this carb can be found on china made 4 quads, pit bikes and pocket bikes.
the carb itself works great but i think it's a tad too small. it's also a pita to get the carb off to re-jet, adjust the float, etc.
on the up side, this set up is excellent for 20" frames (which is what mine is) because the lack of an intake manifold, frees up room for clearance between the air filter and the seat post tube.
Click to expand...
 
Nashville Kat

Nashville Kat

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Apr 20, 2009
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Re: Anyone tried this wider port China Girl?

It IS an RB80 kit:

http://www.ebay.com/itm/80CC-MOTOR-...Parts_Accessories&vxp=mtr&hash=item2a1fe6ad18

So it IS a 66 cc motor-

The 49 "sleeve" Carb you pictured later- I HAVE one of- in fact the carburetion was not good. I just had a thread a few days ago about finally replacing it:
http://motorbicycling.com/showthread.php?t=41385

because, yes it was difficult to take on and off the wider long studs that ran clear to the air filter- and they had a spacing wider- AND they had a unique jet you couldn't change.

But I think it is 40 mm and I think you can get a billet now and just put on another carb- I replaced the jug before I knew that. Anyway, now it runs great

But I'm asking about the newer 66 motor shown here
 
maurtis

maurtis

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Re: Anyone tried this wider port China Girl?

I think he just has the wrong picture there. You can see in the other pictures that the kit comes with a "regular" manifold like my RB80 did, which I bought earlier this year.
 
Nashville Kat

Nashville Kat

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Apr 20, 2009
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Re: Anyone tried this wider port China Girl?

Well then I wonder WHAT the picture is then? I don't think it looks like the "sleve" carb, but I could be wrong. Perhaps it's changed since you got yours.

Also the intake studs- are they wider spaced on yours? Is it the 40 mm spacing?


I'm wondering if this will be the trend of the future.
 
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maurtis

maurtis

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Re: Anyone tried this wider port China Girl?

Nashville Kat said:
Well then I wonder WHAT the picture is then? I don't think it looks like the "sleve" carb, but I could be wrong. Perhaps it's changed since you got yours.

Also the intake studs- are they wider spaced on yours? Is it the 40 mm spacing?


I'm wondering if this will be the trend of the future.
Click to expand...
No idea on the pic, but my intake studs use the 40mm spacing. You can see my thread on it here: BGF RB80, larger intake port

You could always email him, it might be interesting to find out!
 
Nashville Kat

Nashville Kat

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Apr 20, 2009
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Re: Anyone tried this wider port China Girl?

maurtis- I read your thread- interesting- but you never reported how it ran!

I would think the bigger intake and matched port would do quite a lot. Is it the newer 66 Speed carb?

Sounds like you are wanting better carburetion?

So yours has the wider spacing but still the smaller motor mounts?

I noticed the bigger difference on my older 66 simply when I went to the billet first- and the original NT 50 carb was on for awhile- then I put the Speed carb on for another slighter improvement. But the first billet took out all the bogging down. (I've had a slight problem lately that started about the time I put this ultra-small two dollar filter in line- Think I have to go back slightly larger there.)

Anyway the 40 mm billets are $20 and shipping I think- maybe you should just try that first.
http://www.pistonbikes.com/product-p/mmims40.htm

Never mind- when I look at the ads, you'd OBVIOUSLY need the other CNS billet if you eventually go that route. Or use their adapter- same dif tho I think. Unless you just want to gamble for the other cost- shipping has gone up- I got my first billet for iunder $15 a few years back, them another one later on for half off- I think about $12 shipped. I'm not sure what the total cost would be now- more like 30 I guess - too bad.:(
Good luck.
 
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maurtis

maurtis

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Dec 14, 2011
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Kyle, TX
Re: Anyone tried this wider port China Girl?

Nashville Kat said:
maurtis- I read your thread- interesting- but you never reported how it ran!

I would think the bigger intake and matched port would do quite a lot. Is it the newer 66 Speed carb?

Sounds like you are wanting better carburetion?

So yours has the wider spacing but still the smaller motor mounts?
Click to expand...
Thanks for the reminder Kat, I hate it when people do not update their threads! Whoops... I went ahead and wrote a quick update. The motor is running great, but only have about 400 miles on her since I do not ride as much as I would like.

I have the regular NT carb that came with the kit. The carburetion right now is pretty good, throttle response is good, only four strokes at WOT right after start up, idles well. The only reason I would want to go with a different setup is more power. And I saw a video of someone running the RT and it idled REALLY low, which was crazy... Since she is running well now, though, that will be a while. For once, I am tired of tinkering every weekend! I will certainly try just a new shorty manifold first, though.

So of course, the plans for the weekend are to install a centrifugal clutch... wait, what? Didn't I just say I was tired of tinkering? Yeah...

We also just picked up a Thunder Kart for my son that has been sitting outside for about a decade, so trying to bring that back to life. I keep eyeballing that 5HP Briggs. Something tells me an HT powered go kart would not run very well... laff
 
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Nashville Kat

Nashville Kat

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Apr 20, 2009
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Jacksonville, Florida
Re: Anyone tried this wider port China Girl?

I can only relate what I've tried and heard here- you'd probably get more power out of a NT Speed carb, and they seem to be more reliable with less tinkering- just judging from the many posts I see about CNS or others. Of course, someone who knows what they are doing there may disagree- but still they've had several generations of them. I've seen videos on youtube though and they can really scream- I wonder how well the motors last with that kind of revving.

The billet as well would probably give you more, whatever carb you choose- if the motor's fairly level- I have one at about 20 degrees tilt with a Speed carb and it doesn't seem to detract from the run.

I'm getting an easy 25, and a solid 30 out of my 66- above that I think the motor sounds over-revved a bit- would probably go 35 maybe a bit over- I don't need to and in my late 50's I don;t want to fall or crash- 34 sprock, with Speed and billet- and the analogue speedo may run an mph or two slow with the 27" wheels. But it runs and runs and very smooth.
 
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