2 Month old Carbide/Quantum keeps stalling

[gblbks]

I have a Carbide which I bought brand new from TSC on September 3rd, 2009. It has spent two weeks of the 1st month at a small engine repair shop for warranty for the stall problem. The small engine shop guy tested various things and eventually replaced the coil but that didn't fix the problem. When I got it back home I immediately tested it and it died 7 times within an hour. I called American Sportworks the next day and then sent me a new CDI module under warranty as I didn't want to haul it right back to the shop if this was the problem. Replacing the CDI module didn't fix the problem.

Here are the details if you have any ideas. Appreciate any help. The kart will simple just die when being driven. It seems electrical because when it dies it acts like either the key was turned off or the kill switch was activated. It will restart immediately as long as you turn the key to the off position first. If you crank it without turning the key off first, it will turn over but not fire. I think if you let it idle it would probably idle through an entire tank of gas without stalling. This seems to only happen if the engine is idling down or under load.

This happens at really low speeds while my kids are driving it and it has also happened after being driven a gravel road at full throttle for after a mile or so.

To make this even stranger, we have a big downhill area where it seems like if you are going uphill it doesn't stall. If you are driving down hill and come to a hard stop or let it coast to a stop it will die. This seems repeatable.

When it dies it doesn't act like it's a fuel problem at all. It has never acted like it was starved for fuel or ran rough or anything like that. It just apparently loses spark somehow.

One more thing. I just noticed that there is a breather tube or something coming off of the exhaust, right around where the two exhaust springs attach. This breather tube is not in either the printed or online parts manual. The end of the breather tube has a filter or something on it but doesn't attach to anything. It just sits loose above the starter. It this supposed to be pressuring something or is just a exhaust bypass or maybe for emissions?



Thanks

[BuggyMaster]

Fortunately, these aren't too complex of a machine.

Here's what you have to do to start (no pun intended):

Verify that it is in fact a no spark condition if possible. From your description, when it dies next time, confirm that it is dead by turning the key to start it and verify that it won'd fire. Without turning it off (since you said that seems to reset it) check for spark at the plug while trying to turn it over.

Once you have verified a spark problem, report back and I'll tell you where I would go next.

I'll say from your description it sounds like either a ground problem or loose wire somewhere but you need to confirm the spark issue before you start heading that direction.

I would literally carry a spare plug with me to use for the testing so you don't have to pull your existing one out when it dies.

[gblbks]

I'll swing by one of the local auto parts stores and pick up a new plug and use it to verify. I'll do this in a next few days and post the results back here.

Thank for the reply.

[Xrims]

It does seem like it would be a loose wire or ground.I would also check the wires on the rear kill switch mine came loose.

[Krusekontrol]

The wire harness on many of these buggies may get damaged when the slide the wire through the frame. Many good dealers will tell ya that. also the post on the relay could be damaged as well as the jack connecting your cdi. the jack may look fine but the wires often come lose inside, this is also common on the coil connection, the wires looks fine but it's slightly loose and breaks the connection when vibrating.

I'm guessing that BuggyMaster is about to take you through the system step by step. So follow along and you'll master your trouble shooting in no time. LOL! hey I like that. Follow the Buggy Master and you'll master your Buggy.

Now if we can find a wife master to help us trouble shoot the wife life would be great.

[bige]

let me know when you find a way to do that vinny. if the carb is clean then start checking the connections like everyone is talking about. I have seen brand new units that have the wire harnes run thru the frame, but there was no insulation on that section

[BuggyMaster]

Ya, the connections on the coils are exactly where I would be going next. I happened to be looking at ours one day and was amazed that it was running as loose as those wires were.

If you can figure out the wife thing, you will be a rich man.

[gblbks]

I finally tested this with a brand new spark plug and there is good spark. I expected there to be no spark at all but was surprised to have a strong spark when cranking the engine over after it dies. With this test - driving up a slight grade and then turning around and going about 50 feet or so at full throttle and then jamming on the brakes - I paid close attention to engine RPMs and what happens is the RPMs sometimes slow way, way down. Sometimes the engine will recover and idle up to normal speed and sometimes it will stall out. This seems different then how it has stalled out before (like on a level gravel road at full throttle). Perhaps there are two separate problems going on because this sounds more like a fuel delivery problem. I talked to ASW last week and one of the reps suggested maybe it was a low oil shutdown. I had no idea these had a low oil shutdown and can't find anything in either the printed or online manuals (like the small breather pipe/tube coming off the exhaust - nothing in the parts manuals on that either). Just to see what would happen, I put the rear wheels on car ramps to sort of simulate the same amount of incline as the grade I was having this stall on - I figured if there was a low oil shutdown switch maybe I could get this to stall that way - but it never stalled. So I am back to this - if it dies and there is still spark - and it won't fire until I toggle the key switch then is being reset? thanks for the help.

[BuggyMaster]

I think the key switching off and back on fixing it deal is coincidence. From your initial descriptions, it sounded like fuel delivery but it takes elimination of the spark being the problem before you can go that route.

What you are describing is a loading up problem. It's actually kinda normal if you consider what all is going on when you floor it for a period of time and then let off the gas. That aside, what I would suggest to you is to make some adjustments to the air fluel mixture screw that sits on the drivers side of the carburetor.

First thing you need to do is determine how many turns (in 1/2 turn increments) you are out in stock form. So count how many turns of that screw it takes for you to bottom it out and use that for your point of reference (for example: 1.5 turns out). Then, try the screw with 1/2 turn in from stock. So if you were 1.5 out from stock, go with 1.0 turns out then go play for a bit and see how the buggy acts. If the problem gets worse, go 1/2 turn out from stock instead and see how that does (2.0 turns out total). Your goal is to find the sweet spot.

[bige]

These engines dont have a low oil shut down, some of the subaru engines do. does sound like a fuel problem.