Gy6 manual choke? - BuggyMasters.Com - An On Line Mini Buggy Forum and Go Kart Forum

jeffv0802 · #1 07-09-2015, 05:18 PM

Hi guys. I'm new here. This is my first thread.

I got a yerfdog go cart for free from my neighbor because he said it was having electrical issues that he couldn't figure out and it wouldn't start.

The cart had been sitting for awhile so I bought a new carb and I take for it rather than ripping apart the old one

Next I bought a generic gy6 complete wiring kit off of eBay. The wire colors were not the same. It turns out that the wire kit was for some kind of Chinese scooter

Anyway, I was able to match up wires and rig the controls so that I could use the scooter ignition switch to turn it over

I got it to the point where it starts and idles, but as soon as I press on the gas it bogs and dies
no way the carb could be gummed up cuz it's brand new
Any suggestions?

scjeep4.7HO · #2 07-09-2015, 05:29 PM

Choke issue? Is the fuel getting to the carb?

jeffv0802 · #3 07-09-2015, 05:35 PM

I checked the fuel. It's coming out of the line great.

As for the choke...I'm not sure how to check if it's working or not.
The motor idles perfect but as soon as I open the throttle it bogs like its starving for fuel

scjeep4.7HO · #4 07-09-2015, 08:52 PM

It's not unheard of for a little something very in the carb and clog the main jet. Do you have good strong spark?

jeffv0802 · #5 07-09-2015, 10:10 PM

I have good strong spark. Ripped the new carb apart (it's obviously clean as a whistle as it's never really been used) and compared it to the old one.
The only variation that I found was that the inlet where the stem of the vacuum diaphragm inserts in fuel pump on the old one is "springy". On the new one it is not. I'm thinking that it might affect the flow of fuel when it's calling for more gas under vacuum.
If so, I might just need to buy a new carb as ther is no way to replace that piece. It's stamped in...

**SYCARMS** · #6 07-10-2015, 07:43 AM

Not sure what your saying. The fuel pump is mounted on the bottom of fuel tank and not in the carb. Are you talking about the diaphragm for the slide?

jeffv0802 · #7 07-10-2015, 07:54 AM

Not talking about the slide diaphragm. There is a smaller diaphragm that hooks up to a hose that hooks up to the manifold vacuum. I assume that that diagram pulses with the manifold vacuum and let's more fuel through. Am I wrong?

**SYCARMS** · #8 07-10-2015, 08:03 AM

Not sure if your talking about the small diaphragm on the right side of carb. If so some models use internal vacuum and others external off the intake depending on manufacture of carb. If this is what your referring to, it is your deceleration airbleed diaphragm. It leans out the mixture while engine decelerates to idle.

jeffv0802 · #9 07-10-2015, 08:22 AM

Oh - ok - I was totally off then - lol

Well - that was the only variation in the two carbs that I saw. So getting back to my question, I'm not sure what the problem could be. Would going to a manual choke help?

**SYCARMS** · #10 07-10-2015, 08:38 AM

With the ignition on do you hsve power to the enrichment valve?

liduno · #11 07-10-2015, 09:27 AM

Did you compare the jet size from the old carb? As far as checking the choke/enrichment valve, Take it out and supply 12 volts. It should slowly extend, if I remember correctly it only moves out about 1/4 inch. It can take a few minutes to fully extend.

So to be clear, with no power the choke is in the rich position/choke on. With 12 volts it will be in the lean position/choke off.

jeffv0802 · #12 07-10-2015, 09:32 AM

With ignition on, I'm getting .6 volts to the choke connection. What should the voltage be?

jeffv0802 · #13 07-10-2015, 09:41 AM

Quote:

Originally Posted by liduno

Did you compare the jet size from the old carb? As far as checking the choke/enrichment valve, Take it out and supply 12 volts. It should slowly extend, if I remember correctly it only moves out about 1/4 inch. It can take a few minutes to fully extend.

So to be clear, with no power the choke is in the rich position/choke on. With 12 volts it will be in the lean position/choke off.

Yes - I compared jet sizes - they looked the same. I actually put the old jet in the new carb to see if there would be any difference. I will let you know if there is any in a little while
--
I will try the test method that you described for the choke to see if it is working
but
Do you know what the voltage going to the choke should read? Im getting .6 volts

**SYCARMS** · #14 07-10-2015, 10:12 AM

Quote:

Originally Posted by jeffv0802

With ignition on, I'm getting .6 volts to the choke connection. What should the voltage be?

That is correct voltage, the resistor controls the voltage so that the enrichment valve does not close too soon.

liduno · #15 07-10-2015, 10:12 AM

My guess would be 12 volts. .6 is less than 1 volt. [Edit, I missed sycarms post.]

**SYCARMS** · #16 07-10-2015, 11:57 AM

No, if you get 12 volts at the feed wire the enrichment valve will close too soon. This is the reason for that resistor in the electrical box, it controls the voltage to the enrichment valve. One point you brought up that I missed for I seen it as 6V and not .6volts. Depending on manufacturer voltage should be anywhere from 4V to 9V from my experience. If his reading was indeed .6V that would not be near enough to close off the enrichment valve therefore causing a very rich mix when engine is at operating temperature.

liduno · #17 07-10-2015, 03:21 PM

Quote:

Originally Posted by SYCARMS

No, if you get 12 volts at the feed wire the enrichment valve will close too soon. This is the reason for that resistor in the electrical box, it controls the voltage to the enrichment valve. One point you brought up that I missed for I seen it as 6V and not .6volts. Depending on manufacturer voltage should be anywhere from 4V to 9V from my experience. If his reading was indeed .6V that would not be near enough to close off the enrichment valve therefore causing a very rich mix when engine is at operating temperature.

I know the newer valves don't have an external resistor, they would need 12 volts to operate properly.

jeffv0802 · #18 07-10-2015, 07:45 PM

Ok, im not sure why the leads are only putting out .6 volts. can I just find a 12 volt wire and connect a lead to the resistor and ground the other side of the resistor?

liduno · #19 07-11-2015, 11:08 AM

The power to the choke/enrichment valve needs to turn off when the key is off.

**SYCARMS** · #20 07-11-2015, 11:46 AM

I would first try tracing that wire to see where the problem lies. Just routing around the problem still leaves the problem to possibly effect something else. Many of these wires are not a direct connection but piggyback off other wires. It's always best to find and repair the problem rather than bandage it. These harnesses are not that complicated, it just takes time to unwrap and trace the problem to repair.

buggymike1976 · #21 07-11-2015, 02:44 PM

liduno..

I am not sure if you have tried this or not..... lets eliminate the choke all together..... go ahead pull screws off side of choke and put a piece of gasket across hole in area where fuel comes out.... once you eliminate choke.. start engine and with it idling very slowly increase throttle... if it will rev up that way... then your getting to much fuel upon throttle advancing... second thing you can try is with your air filter off see if it responds, if not put have of your hand over opening of carb, and try to advanced throttle... if it tries to rev up then it is not getting enough fuel or to much air... most likely fuel... let me know what happens..... EXCUSE THE grammar and spelling for all you out there on a tiny phone. lol

Mike
H&K BUGGIES
REPAIR AND MODIFICATION

liduno · #22 07-12-2015, 09:47 AM

Quote:

Originally Posted by buggymike1976

liduno..

I am not sure if you have tried this or not..... lets eliminate the choke all together..... go ahead pull screws off side of choke and put a piece of gasket across hole in area where fuel comes out.... once you eliminate choke.. start engine and with it idling very slowly increase throttle... if it will rev up that way... then your getting to much fuel upon throttle advancing... second thing you can try is with your air filter off see if it responds, if not put have of your hand over opening of carb, and try to advanced throttle... if it tries to rev up then it is not getting enough fuel or to much air... most likely fuel... let me know what happens..... EXCUSE THE grammar and spelling for all you out there on a tiny phone. lol

Mike
H&K BUGGIES
REPAIR AND MODIFICATION

Removing the choke/enrichment valve leaves the buggy in a full rich condition.
The choke/enrichment valve is in a normally on position when no power is supplied. It extends when power is supplied, which is the equivalent of turning the choke off.

The choke/enrichment valve extends and closes an internal port that leans out the mixture. With the choke/enrichment valve removed, that port will be left open.

Even if you make a plate and gasket to cover the hole the choke goes into, the internal port will be left open.

Unless you're saying to block off the internal port? That would eliminate the choke.

buggymike1976 · #23 07-12-2015, 12:20 PM

Absolutely right but I am saying using the gasket material between the choke plate and carb....and when you do that no extra fuel goes to carb....all my chokes on my buggy is useless In Florida and with out altering much of original condition I figured this is easiest way...and it is very quick and easy way to eliminate choke for troubleshooting purpose's....

buggymike1976 · #24 07-12-2015, 02:02 PM

Liduno, by the way that was not directed to you originally...that was to jeffv0802

liduno · #25 07-12-2015, 03:26 PM

Gotchya, as long as you block off the port and not just the place the choke goes.

jeffv0802 · #26 07-12-2015, 03:57 PM

I'm sorry - I don't follow...
Are you saying stick some gasket material down into the seat where the choke needle goes to block off the enrichment ports?

buggymike1976 · #27 07-12-2015, 04:26 PM

No there are two side screws that hop choke assy to carb remove those and install gasket....i gave pic the two screes most FWD faceing

**SYCARMS** · #28 07-12-2015, 07:37 PM

Are you having these problems with a cold engine or a hot engine?

wildbob · #29 07-13-2015, 06:21 PM

Just my two cents coming from a guy that has been battling a new carb running extremely rich no matter what jets he used....double-check your float adjustment

I fought my new Mikuni since the fall, originally thought the float level looked good come to find it was off quite a bit. I got it in range and was ripping around 10 mins later.

jeffv0802 · #30 07-18-2015, 10:19 AM

Hi Guys - thanks so much for all the comments and help.
So
I got it running, but im not sure what I did... I took the carb off, cleaned it one last time and then put it back on. It started up, ran and didnt die when I pushed the gas pedal.

It has plenty of power, but I have noticed that when I run at top speed for a minute or more it will start sputtering and loose power. If I lay off the throttle for 15 seconds, I can go top speed for a little while longer. My guess is the float bowl is running out of gas.

The carb has a plastic float, can these be adjusted? I dont see any screws to adjust...

liduno · #31 07-18-2015, 10:46 AM

Some have a little metal tab that you can bend to close the float valve sooner or later and some don't.

Are you sure the problem isn't in the fuel getting to the carb?

jeffv0802 · #32 07-18-2015, 11:36 AM

Fuel is coming out of the line very well when I take it off the carb so I don't think it's a problem with the fuel line. I will have to pull the carb again and look for that metal tab. Thanks. I'll let you know what I find

**SYCARMS** · #33 07-18-2015, 03:30 PM

Check that the fuel cap is vented. Some older caps were not ethanol compatible and would deform on the inside from the ethanol.

ckau · #34 07-19-2015, 09:02 AM

Quote:

Originally Posted by jeffv0802

Fuel is coming out of the line very well when I take it off the carb so I don't think it's a problem with the fuel line. I will have to pull the carb again and look for that metal tab. Thanks. I'll let you know what I find

don't fiddle with the float. make sure it's at correct specs. The problem is with fuel delivery. Stock fuel lines are too small, you use more fuel than the line can deliver at extended high speeds. Go to a larger fuel line and a high capacity filter.