Latest Buy - Looks to be a 150cc GY6 Go Kart - Starting / Idling / Carburetor Issues

[Role]

Just bought this kart it's a much bigger kart than I have seen in a while. Only one I have seen of comparable size is a Tomberline Crossfire that I had at one time.

Guy that I purchased it from gave me brief history on it.
Kart was his wife's and her father had bought it for her a few years ago. She got to where she never rode it anymore and it sat for a while. A close friend of theirs said he could fix it and took little bits here and there off of the kart and left it. Worse than I thought, when I say "left it" literally with carb off oil cap off, gas cap off .. You get the picture.

1. I knew where the biggest problems would lie. I started with the gas tank. Removed little particles of rust with apple cider vinegar and BBs, shaking vigorously for long periods of time and rinsing with distilled water. Repeated this process over the course of 2 days. Gas tank is good now.

2. The peacock valve under tank was broken off so I wen to local hardware store and got a new setup. Basically it's just a gravity feed now. Bought a new inline gas filter also.

3. Took my air hose and lightly sprayed out the oil casing with the oil plug off. It was some sludge to say the least. Following that I filled it back up with oil.

4. Cleaned the carburetor (3 times now) vigorously. Everything off the carb, main jet, pilot jet, diamonds inside choke chamber with copper wire, air screw hole, etc. Went through 3 bottles of carb and choke cleaner to make sure I got everything.

5. Checked all the wiring, spark plug coil, changed spark plug to an NGK C7HSA and set the gap to .025" inches.

6. Put a new battery on the kart (did not have one on it)

7. Drilled out the key hole because he didn't give me a key and I like the universal feel of any key, haha.

8. After several attempts to start it and looking for vacuum leaks because I felt either not enough air or either not enough gas was causing the issue. When I went to start it and would let it sit for about 5 mins, I would come back and it would fire up, but I would have to have my foot full throttle and then after 5 secs or so it would die out.

9. Finally got it cranked enough to get it moving and went around my block one time. While driving it I kept it full throttle and noticed I was moving about 10-15 mph. The engine wasn't reving high at all, it was limited. Hydraulic brakes and e-brake weren't riding the rotors either. No slipping on the cvt either, it was smooth the whole time, just limited rpm.

My idea was to get the engine warm enough to then adjust the idle and fuel. I also wanted to cycle the oil in the motor with it being warm to cycle any missing debris or sludge that was left behind.

After this short ride today I pulled it back in the garage and immediately when I let my foot off the gas it immediately died.

10. While the engine was a little warm I waited about 10 minutes and then drained all the oil that cycled through it out.

11. Put fresh oil in it and this time I used Marvels Mystery Oil to substitute 20% of the oil. So I did around 700ml of 10-40w SAE Pennzoil and then did 200ml of Mystery oil.

12. I then put a half a tank of gas in it. Gas was mixed with mystery oil and some seafoam for good measure and to help with the ethanol and carb deposits.

The only thing that I can think of at this point is one of three things.

1. Carburetor - however, I've cleaned quite a few in my day and I ultimately don't think that's it.
2. Valve adjustment.. Seeing as how they apparently left the kart to die and women maintaining anything is usually not the case, I doubt the valves have ever been adjusted.
3. Piston / Rings could be bad - but I question this some because the cruise around the block today was not at all jerky or knocking, just limited engine and RPM feeling.

Anyone want to help me narrow this down?

Few things that would be helpful:
1. Type of kart? So I can locate a service manual
2. If valves need adjusting I don't know what to adjust it to.
3. I've looked around on various sites for this model and can't find it.. I noticed the rear axle is different from most I've seen, it's all built into the casing of the motor both ways, you can't even see any axle. Has turn signals, low/high beam, 4 DISC BRAKES w/ e-brake, dual horns, rear view mirror, and 12v charger port built into dash. Don't see a gearbox for reverse or anything, unless it did at one time and was taken off.

I did notice when I had the rear end jacked up off the ground, when rotating one wheel a direction would cause the other to spin the opposite direction.


Anyway, I'm ready to knock this out and finish this project up, my little boy has been wanting to cruise in it since I got it.

Any help would be appreciated, thanks guys and gals.

-Role

 

[Role]

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[Role]

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[Role]

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[Iron John]

I would not run the engine with MMO in the crankcase.

Modern engines have detergent additives in them for a reason. Those additives are not MMO for a reason.

Change the oil again and then resume troubleshooting. You can always perform an accelerated oil change again later if you are worried about sludge.

 

[Role]

I would not run the engine with MMO in the crankcase.

Modern engines have detergent additives in them for a reason. Those additives are not MMO for a reason.

Change the oil again and then resume troubleshooting. You can always perform an accelerated oil change again later if you are worried about sludge.

Any idea on what type of kart it is? I got it running and actually idling today. I changed all the fuel lines with a smaller gauge because I noticed underneath the tank was a little gas seeping through the top of the hose.

I drove it for probably 15 mins. Let sit, cranked it back up and it fired up after 2 tries. While the engine was warm I went ahead and set the idle and air.

Left for about 3 hours and came back to it and it's as if I'm starting back from scratch - wouldn't start at all.

I'm guessing because it's gravity fed that gas is just sitting in the carb causing too much gas and as a result, it won't start now?

Probably going to get a gas shut off valve tomorrow.

Any ideas? Help is appreciated. This thread is a ghost.

 

[superballskart]

Your probably flooding it idk if these have overflow tubes but even if it does it can still happen fuel needs to be off for the reason in the bike world we even turn our gas off a block or two before we get home just so gas don't sit in the carb.fuel shut off is a must

 

[Thingem3376]

Typically what causes a condition like that is a sticking float needle, do you notice any fuel leaking out from between the bowl and carb body? When you got it starteddid you notice any smoke, and did you change out the spark plug?

 

[Iron John]

Any idea on what type of kart it is?

It's a yellow cart with the engine oil thinned with MMO so that the bearing surfaces inside can scuff and gall when the motor gets warm and is run fast or hard.

 

[crazykart]

It's a yellow cart with the engine oil thinned with MMO so that the bearing surfaces inside can scuff and gall when the motor gets warm and is run fast or hard.

The main ingredient in MMO is naphtha oil, the other ingredients are mainly detergents. It is a great product to use for a short period of time to flush out any deposits. Idk why you have such a hatred for it, but it is nothing that is going to damage any part of the engine when used to flush out deposits. Now I would not run it for a long time, maybe a few good hours of riding, and then drain and change with a good grade oil.

It really is nothing to get bent out of shape about though, and I'm not trying to be harsh or anything. Just used properly it works, and adding 20% or less vs 80% or more oil is rnot going to damage anything.



Have you checked for vacuum leaks around the block? Take some carb cleaner or starting fluid, start the engine, and spray around it, away from the carb, all around the engine. If you spray near a spot and it revs up for a second you more than likely have a leak. Could be a gasket or whatnot.

 

[Role]

Iron John, I agree with crazy kart. 80% oil to 20% MMO should not hurt it at all. Remember this stuff is run in automobiles and big equipment to expand the life of the cylinders and motor. On a smaller engine like this, I could not foresee it ever messing up the engine if it's just run a few hours with it.

Moreover, obviously it is a yellow kart (not color blind) .. I'm wanting the specific model of the kart or someone who has an owners manual so I can see about servicing it using the correct factory specs.

Thingem- it does have overflow tubes. I did notice on the auto enricher beneath the two screws there was some dripping out at a little at some point. But then it stopped and haven't seen it do it since. I had reversed the rubber grommet inside the pressure release valve and I'm pretty sure that's what caused it. When I corrected the pressure release valve, it has stopped any type of leaking from the auto enricher since.

A little bit of oil has sputtered out of the breather tube and it's got some white smoke coming out of the breather tube. ??

 

[Thingem3376]

That's normal for engines with a PCV, (Positive Crankcase Vent) as theses engines were never built for tight tolerances but to much will cause fouling of the plugs, and could indicate the need for rings. IIRC you said you were running seafoam and that causes smoke, so get rid of the seafoam for accurate diagnosis. I am not familiar with your engine, but I am an automotive mechanic so some of this is a given.

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[Role]

That's normal for engines with a PCV, (Positive Crankcase Vent) as theses engines were never built for tight tolerances but to much will cause fouling of the plugs, and could indicate the need for rings. IIRC you said you were running seafoam and that causes smoke, so get rid of the seafoam for accurate diagnosis. I am not familiar with your engine, but I am an automotive mechanic so some of this is a given.

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Do you think a contributing factor to the hard to get started and idle and limited RPM could be just a vacuum leak or possibly the valves need adjusting, or both?

 

[Thingem3376]

Definitely, a vacuum leak will kill an engine, someone recommended using carb cleaner to find vacuum leaks, do that,personally I prefer brake cleaner. With the valves if you have a mechanics stethoscope take a listen for clicking, or use a broom handle, I hear that works well. A quiet click is is usually normal, but if it is audible without a stethoscope you will need to adjust the valves.

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[Role]

I'm going to look for vacuum leak and do a valve adjustment for good measure. I also have 2 other carbs that I could probably use or just replace float needle from one.

Got to go get some feeler gauges at Harbor Freight, don't have any that small. What should I adjust the valves to?

 

[Thingem3376]

Here's the best I can do for you.http://gokartsusa.com/pdf/GY6_150_Valve_Adjustment.pdf

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[crazykart]

Ya brake cleaner works good too, usually cheaper. I figured you would have some carb cleaner laying around from the previous cleaning of the carb iirc you said you had.

A broomstick, or any wooden pole (dowel,etc) does work well, though it is less audible then a stethoscope.

 

[Role]

If this weren't a G rated forum for profanity, I would cuss a blue streak right now.
I BROKE THE SPARKPLUG OFF in the hole.

No idea how I'm going to get it out. I don't want to take the engine apart either. It's still in the threads.

HELP!

Here is what is left of my wonderful NGK spark plug. And for the record, I didn't over tighten it. It broke while I was still wrenching it in.

 

[Thingem3376]

Looks like you got to order up a new head gasket, because that head is coming off. That sucks, have you tried using a flat head at an angle in a way that it would dig into the insulator and rotate it out of the threads? It's that or you're gonna be inspecting your piston and cylinder.

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---------- Post added at 08:40 PM ---------- Previous post was at 08:37 PM ----------

Picture of the head with the sparkplug please.

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[crazykart]

It's in the threads...may be saveable/pullable. I agree with the screwdriver, BUT first get a really sharp chisel that will fit in there. Lightly tap on the chisel to try and cut a notch into it, then take a big flat head screwdriver and try to turn it. Not too hard on either tapping the chisel or turning the screwdriver!

If you can get lucky you can unscrew it like that and get it out. Worse that could happen is you shatter the plug more, and have to take the engine apart anyway like you may have to anyways lol.