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northwest Texas
02-02-2008, 11:29 AM
Hey Josh, since youseem to be the only guy around this forum, I need to pick your brain.

The other night, I was about 100 yards from home when my KQ700 died. At first I thought I was out of gas but was only low. I managed to get it fired back up and limped to the barn where I added a couple gallons.

It was still hard to start and once going, felt like an old carbureted engine that was getting too much gas. It would barely pull itself to 20mph and wasn't any better in low.

My FI light hasn't come on in the dash but I added alittle carb cleaner and ran it but it still hasn't helped. I can start it up cold and it runs about a minute fine and then just dies and is a bear to start after that (since the other night) Try to rev it and I really have to feather the throttle and it will start stuttering and popping out the exhaust.

Flipping through my service manual last night, maybe a vacuum line has come loose?

Until then, other than taking a long time to start cold, she hasn't skipped a beat in the 50 +/- miles I've put on it since I've had it (05 model) and it was just fine the 10+ miles I'd been riding it earlier in the day and that evening.

firefighterjosh
02-03-2008, 12:39 PM
How many miles/hours are on it all together?

Have you changed out the stock filter?


I would check a few things. First make sure the air filter is clean. then I would change the plug. Also make sure the boot on the plug wire is making a good connection. When you pull the spark plug boot off make sure there isn't a ton of mud in there. I would also spray it with dielectrical grease.

Have you relocated the gas tank vent tube?

If it still runs like crap and you haven't changed the vent tube you may have gunk in the tank. You can see the vent tube vavle (orange) under the left side fender. (drivers side in a car). You can grab it and pull it out. Make sure it clean. Sometimes it will fill with dirt and let in a bunch of mud. If its not working or is stuck open it might be time to pull the tank and check it out.

Its not really too hard to get off. I had my tank out within 1 hour.

hope this helps

northwest Texas
02-03-2008, 02:55 PM
Thanks, I'll give it a check next week hopefully.

What gets me is it was just sudden, just like it run out of gas and it wouldn't start hardly.

I'll check the vent tube as per the manual as well. Hopefully it's just something as simple as that.

The quad has about 4300 miles on it now. Here in this neck of the woods, guys put 10,000+ miles on their quad checking irrigation engines and sprinklers.

firefighterjosh
02-03-2008, 03:03 PM
Let me know what you find good luck

4trax250x81
02-03-2008, 04:15 PM
I would also check the vent tube for the fuel tank. It sounds to me like thats the problem, that would be my first place to check.

northwest Texas
02-04-2008, 04:41 PM
Ok, here's the deal. It fires up just fine initially and will idle fine for a couple minutes before it dies.

What it acts like is if it's not getting fuel to the "carb"

I blew back through the vent tube and it was free of obstructions. So then I thought maybe the gas cap was maybe the problem.

It doesn't matter if the vent line is on or not, nor does it matter if the gas cap is on or off, eventually, it will start coughing and sputtering from what seems like it starving for gas.

So where next? I'm sure the fuel pump is pumping enough fuel initially because after a few minutes, it will fire right back up and rev fine before "starving for fuel"

After it starts "starving for fuel", you must give it several minutes before the symptoms go away and it fires up cleanly.

A couple years ago, I didn't notice I had a kink in my gas cap vent hose on my 400EX and it would run but not great. It'd fire up and run great until there was a vacuum and the carb couldn't get the gas out of the tank. This is almost identical to that, if you understand me now.

firefighterjosh
02-04-2008, 05:20 PM
If you took you gas cap and vent tube off that must not be the problem. My guess would be is that it has gunk in the tank.

Its really not too hard to look at.

Just take the rear rack and plastic off and the tank is right there.

You will see (i belive white) screw on lid that would screw right off and take a peak at your fuel pump and bottom of the tank. If theres dirt I would suggest taking it out all the way and cleaning it.

firefighterjosh
02-04-2008, 05:22 PM
BTW you can see the lid on top of the gas tank in this pic. It looks like it will srew off.

http://www.nyrocatv.com/forum/photo/173454.jpg

northwest Texas
02-04-2008, 08:13 PM
I already have the rear fenders off and see exactly what you're talking about. It looks like the pump will come right out.

Bad thing is I just poured 2 gallons in there when this all started.

I hope you're right that there's just a bunch of junk plugging the intake preventing sufficient fuel getting to the combustion chamber. You would think though that with all the shaking I've done on the thing some of that might break lose and it would run right, maybe for a quick drive or something.

But a couple years ago, I had some clutch plate start flaking and they would plug up the screen partially on my tractor and the only way to fix it was to drain the transmission, pull the screen and clean it off and get out what I could through the hole and do it again. After about 3 or 4 times of doing that, I haven't had any more trouble (knock on wood)

That might also explain why at 62mph it would start cutting out like it was hitting the rev limiter and it was starving for fuel. It was fine at 61mph but at 62mph it would act up and not go any faster.

I'll try to take a look at it tomorrow.

firefighterjosh
02-04-2008, 08:19 PM
While your at it I would relocated that check vavle too. I ran mine on top of my air intake

northwest Texas
02-11-2008, 04:12 PM
Well, I got the tank out and the fuel pump out of the tank. I don't know how much dirt I let in vs how much was already in there but I'd say it was pretty dirty. Being used on the farm, there's lots of opportunities for dirt to settle in places you wouldn't think it could.

Anyways, I removed the tray on the bottom of the fuel pump and cleaned the screen thoroughly (or what I could). It was grimy and just a solid dark color. I used about a can of carb cleaner but I can't completely free it of what looks like dirt trapped inside. Can I remove the screen to try and do a better job? It looks like it slides in but I'm not sure and I don't want to break anything since a new fuel pump is in the $300 range.

What do you guys think?

firefighterjosh
02-11-2008, 04:44 PM
There was a guy that said it could be removed but he wont say how it comes off. He wants to charge ppl to do it.

They say it can't be done but I am sure there is a way. I would just clean it really well and run it. If it runs bad still then start taking it apart.

northwest Texas
02-20-2008, 09:19 AM
It was the screen at the bottom of the fuel pump. I got it back together yesterday and it fires right up now instead of the 20 seconds of cranking it took before.

It seems to accelerate faster than before but that could be the lack of seat time.

I still have the stutter, like hitting the rev limiter, at 62mph. Its fine at 61mph. Could I be hitting the rev limiter?

firefighterjosh
02-20-2008, 12:08 PM
Ya thats prally the rev limter. Do you have any clutch work or bigger tireS?

northwest Texas
02-20-2008, 05:41 PM
Nope, it's all stock so far as I know. Have a set of All Traks ready to be installed once I feel like messing with it.

I was thinking the guy said he had hit 65 or 70mph with it while I was looking at it.

62mph is pretty fast, even on long straight stretches of road.

firefighterjosh
02-20-2008, 05:47 PM
When mine was all stock I was hitting 72 MPH bouncing off the rev limiter.

Did you try cleaning the clutches? Just some compressed air would work

northwest Texas
02-20-2008, 06:30 PM
Nope, what do I do? Pull clutch cover and hit the thing with air?

firefighterjosh
02-20-2008, 06:47 PM
Do you know how many miles are on the belt?


Yes you are going to have to take off the peg in order to get the side cover off. Some people use some soap and water. But I think you would be ok with just some compressed air. Be careful its going to make a huge mess. Be sure to get the primary clutch really good. There are weights behind the plate and if there is belt dust built up they will stick.

If your belt is worn it might be slipping at the higher top speed so that is why its hitting the rev limiter faster.

I would prabably buy a Dayco HD belt or the Highlifter King quad belt (same thing) there alot cheaper then OEM and seem to last just as good.

You can change the belt without Taking the sheaves off. If you decide to do that I can tell you a easy way.


Also where the belt rides on the sheaves I would take a rag and carb cleaner and wipe them off. I just squirt the carb cleaner onto a rag and then wipe down the metal plastes. be sure not to get fingure prints on them

Hope this helps

northwest Texas
02-20-2008, 07:05 PM
I'm sure it's the stock belt, some 4,000+ miles, I forget exactly.

I've thought about replacing the belt so when I do, I'll get back with you.

firefighterjosh
02-20-2008, 07:11 PM
When you take your clutck cover off there is a little cage thing over the Primary. Its held on with 8mm bolts. Take it off. Then go to the secondary. There is 2 threaded holes. Take two of the bolts from the cage and put them in the holes. Then start to tighten them down. You will see the secondary separate from the belt. That way you can get it out.

Use the same method to get it in