Adrian Ciotinga

As the title says, I hear a knocking noise coming from the CVT cover. It’s fairly quiet (never noticed it before now) and the only reason I paid any attention to the cover is because I went to start the quad and heard a clunk (possibly from being between neutral and drive). As far as I’m concerned, it only happens in neutral as I could not hear anything when riding it. It’s quiet enough that I feel it might be just a normal noise. Any input would be greatly appreciated.

It backfires when I give it wayyyy too much gas when trying to start it. Never when riding though, nor when properly starting it.

So I’ve had this quad for the better part of a month, and it’s been hard to start since the day I bought it. Once it warms up it idles just fine and has plenty of power and starts no problem, but cold it takes 20 seconds minimum of straight cranking to start it.

It’s not really too big of an issue, I’m just curious as to why it takes so long. Earlier today, it took me about 2 minutes of on/off cranking to get it to fire.

i have attached a video of a cold start to show you what I mean.

Yeah, I was low on coolant. It was at the minimum fill line on the reservoir.

Crisis averted! It was overheating. After leaving it an hour to cool it star ya just like before and idles great. Rode it around the block a couple times and everything’s in order. One question though: is this air duct (coming from the CVT) meant to be like this?

Hello,

I recently picked up an ‘07 KFX 700. All was going well, rode it about 40 miles, when it started bogging at low speeds. If I kept the revs higher, I was just fine. Also, a persistent issue since I picked it up is the fairly difficult start (but it is abnormally cold right now and the quad is jetted for the dunes at summertime).

Regarding the complete lack of idle, I have to rev it a couple times to get it to idle after starting it, after which it’s 50/50 whether it remains idling. I don’t have low fuel, but all of this began after I rode it pretty hard and the radiator fan kicked in. Might be overheating, just wanted to hear your opinions.

Yeah. Never rolled, only bumped into a tree on the front bumper.

Decent turning radius. It does pop the wheels up pretty easily though.

It’s exceeded my expectations for a CVT quad to be honest. So far, I’ve never felt that I’m out of power or that I could ride any better with more power. However, it was decently hard to start (especially after I held it at WOT while trying to start... my bad), but nothing that can’t be attributed to colder weather or a bad battery. Just replaced the battery, as the old one was bad, and it starts like a dream.

Here’s a pic of it sitting in my garage, and hopefully I can get a riding video tomorrow.

I bought the quad last night for $2500 including a set of new paddle tires mounted on rims. To the best of my knowledge, there was nothing wrong with it, and the guy appeared to have taken really good care of all of his machines. I plan on selling the paddle tires as I have no intentions of going to the dunes. The quad is pretty clean, the only scratch or visible damage being on the front bumper (he acknowledged that in the ad). Thanks everyone for your input!

Also, it is a dune quad. Would that result in any damage I should look for?

Thank you. Hopefully he sees this before I go to check it out 😊

I am checking out a KFX 700 later today. From the pictures, it looks like the front rims are aftermarket. Is there any reason to worry? Also, does anything else stand out as odd?

Sorry for not posting in over a month. Today is the first day in over a month I am able to work on the quad.

If the piston and rings look good, what do you think the problem could be? I have a replacement piston, however I could not manage to get the long studs off.

I am in a bit of a predicament right now. I managed to get the timing chain, camshaft, and head off of the engine but due to the engine still being on the quad and an odd frame design I am unable to fully remove it from the rest of the machine. I have managed to slide it and the cylinder far up enough to where I have clear access to the piston. I firmly believe that if I were to remove the engine from the quad that it would never run again. What should my next step be? Here are some photos of the piston and what I’m trying to describe:

I can’t seem to get the chain off despite fully removing the chain tensioner. The chain has slack but not enough to remove it fully.

I have removed the carburetor, exhaust, valve cover, and timing chain tensioner. I can’t seem to figure out how to remove the timing chain sprocket. Here is a photo of the sprocket:

This is where I am at right now. How would I go about removing the valve system? I do not have a torque wrench (which I heard might be an issue).

Sorry for not posting for a while. I got very busy the past two weeks.

Anyways, I believe the problem to be oil getting past the piston rings and into the combustion chamber. The quad starts very hard and doesn’t stay running for long. I got a piston and ring kit to install. I’ve read online and am going to remove the exhaust and valve cover. How do I remove the valves so I can reach the combustion chamber?

No more smoke and it drives just fine. Just gushing  oil from the tube.

I went on a longer ride (~10 mins) and everything is not ok. The left rear tire (the side the hose is on) is covered in oil spatters and the frame under the hose is too. It appears that I drained enough oil to the fill line but it didn’t work. On the bright side I’m no longer blowing smoke and the quad performs like it did before all of this.

I tried what you suggested and it runs just fine! Just curious, why would it start smoking just now after about 30 mins of time spent riding it?

Yes. Would that cause it to smoke from the oil vent hose?

When I tried to start it up it started spewing white smoke. Not from the exhaust but just from the head of the engine. I shut off the quad as not to damage the motor any more. Any ideas what it could be?

The white smoke started instantly after I started it, which leads me to believe that it isn’t oil that might’ve accumulated on the outside of the engine burning.

Oil is coming from the end of the tube visible in the first photo. The tube is pointing directly down and is right over the oil spot visible on the ground.

And as for the bolt missing I removed the bolts holding the footrests onto the frame so I could look under the engine easier. I was in the process of reattaching when I took the picture.

A new issue has arisen that isn’t the brakes. I am leaking oil. There is a hose coming from the cylinder head that is leaking oil. Any help would be greatly appreciated. I have attached photos of the tube leaking oil.