zuma zrf70 carby issue

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blkwdw

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Got a zuma zrf70 at home. Having trouble with it running at wide open throttle. It starts fine. Idles fine. Revs slowly to bout half way fine. if u give it a quick blurt of the throttle it bogs and if u give it full revs it dies. At 3/4 throttle it spits and sputters and slowly dies down.
Ive cleaned the mainjet and pilot jet. I can see light through them both so there clean. I tired the carby on our other zrf70 and it done the same as that rules out an plug, coil ect issues as it runs fine with its carby. Could float height be an issue? is the spit and sputtering a lean or rich jetting issue?
 
Spitting and sputtering is usually from being too rich.
When you had the jet's out, did you check the hole is open at the bottom of the thread's where the pilot jet screw's into in the carby body ?
Did you take the emulsion tube out where the main jet screw's into and check the hole's across that are all open.
The float being set too high can make the bike run rich, the tab on the middle of the float arm normally start's to close the needle and seat when the float is sitting level with the fuel bowl mounting face of the carby.
Is the needle clip still on the centre notch of the needle ?
 
I poured fuel down both hole where the pilot and mainjet screw into and fuel flowed through fine.
I took the whole main jet out and cleaned it all out. I can see right through them both. How do you know whats the correct float height? Havnt checked the needle position. It seemed to rev better though at the richer setting
 
Have you blown compressed air in though the 2 or 3 small port's on the air filter side of the carby and checked that you can feel it coming out the main jet and pilot jet hole's ?
Float level depend's on what carby it has.





 
my67xr said:
Have you blown compressed air in though the 2 or 3 small port's on the air filter side of the carby and checked that you can feel it coming out the main jet and pilot jet hole's ?
Float level depend's on what carby it has.

http://s598.photobucket.com/user/xrfairmont67/media/mini bike/carby/009_1.jpg.html

http://s598.photobucket.com/user/xrfairmont67/media/mini bike/carby/003-2.jpg.html

http://s598.photobucket.com/user/xrfairmont67/media/mini bike/carby/004-1.jpg.html
Click to expand...

I can see light through all the holes except ur emulsion tube or wateva it is isnt as open as the one in ur pics but i can still see by eye from one side through to the other. Its starts and idles perfect. slow revs fine to half throttle. go past there and it plays up and if u give it full throttle it just dies. Also dies when u give it a quick rev. Ive got 2 bike and there doing the same thing. I ran the choke on one of them to see if it helped and it did as it ran normal but wouldnt idle at all.
 
What carby is on it ?
Can you post up a pic or a link?
 
One carby is a DENI carb and the other is a Kf carb. Got both bikes reving properly now but blow heaps of fuel out the exhaust now and wont idel at all. I pulled all the jets out and cleaned them up more a small drill bitl and it opend them up more.
 
The clip on the needle is in the middle as well.
 
Opening the jet's up with a drill bit is no good, that's why it's blowing fuel out the exhaust now.
I would be looking for a replacement carby for it
 
I used a smaller size drill bit then the holes were and used a drill bit and pliers to clear the jets. No drill used.
 
Does the carby look like this or similar?

images


Most people don't have a drill bit set fine enough to run through the jet's.
The pilot jet hole through the middle is about ·3mm diameter, and the Main jet hole would be about ·6mm - ·7mm

The mixture screw should be about 1¾ to 2 turn's out.


Float level should be close on level with the carby base fuel bowl mounting face when it's held upside down,
the float will be slightly closer (about 2mm) to the fuel bowl mounting face on the opposite end to the float pivot pin
 
I didn't know I had a set but found a small metal box set of bits all less then a 1mm. Wouldn't fit in the drill even if I wanted to use it there that small.

Yes that's what the carb looks like. Mixture screw is set to 2 turns out. Float sits level with the carby when it's flipped upside down and sits in the shut of position. Doesn't matter where i turn the idle screw even all the way in it won't idle. The idle never changes when moving the screw
 
That mean's the pilot jet is too big then, try running it without an air filter see if it run's/idle's then, that'll make it leaner
Choke was definately off?
 
Choke definitely off as it just does with the choke on now
 
This carby is the same as the one you have linked but will be better with the foam air filter.
You just need some foam filter oil to spray on it to stop dust getting through - Castrol Foam Air Filter Oil - 300g - Supercheap Auto Australia
The mesh style filter's aren't too good at stopping dust etc.
PZ 19mm Carburetor Carburettor AIR Filter 35mm 50cc 125cc ATV PIT Dirt Bike | eBay

Or there are these 2x carb's which are $38ono, and buy the filter's from him too for $20 ono-
2X 19mm Carburettor Carby 50cc 90cc 110cc 125cc ATV Quad Bike Dirt Buggy PIT PRO | eBay
2X 35mm AIR Filter Foam Cleaner 50cc 90cc 110cc 125cc Bike Dirt ATV Quad PIT PRO | eBay
 
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The one i posted had a foam filter. Foam filters doesnt bother me as i have to clean and oil our bigger bikes(500exc 250excf ttr125) filters anyways.

So the link with the carby and filter will be fine even though its slightly different to the carbies on the bikes now with the choke on the right instead of the left?
 
Yeah they will work,
what size carby's are on your's now 17mm or 19mm, you could even have a 20mm or 21mm carby on them.
Smaller is best especially since it's on a 70cc.
I only linked a 19mm carby because they were the same as what you linked.

These 17mm carby's might be better with the choke on the left, i think the mixture screw is on the right though so it'll be a little harder to adjust it
17mm Carburettor Carby 50cc 90cc 110cc 125cc ATV Quad Bike Dirt Buggy PIT PRO | eBay
 
19mm now. with the 17mm the bolt holes arent the same though. Will stick with the 19mm. not after power just want it running for the kids to ride
 
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