Hello,
Newbie to the board here. I've been around quads all my life but always the 4 stroke breeds. I don't know much about the two strokers. Here's my story.

********Full story below******** Cliff notes: KFX 80 sat for a long time, new owner, now smokes like crazy!

I picked up a couple of new to me quads for my kids. Got them from my bro-in-law who never did anything but ride them, doesn't really even know what end of a screwdriver to use.

Anyway these quads haven't been ridden since about 2008. The first was a chinese 50 model that I found just needed a carb cleaning and battery, now it runs like a champ.

The other is a Kawasaki KFX 80 around 2005 vintage(don't have title yet and haven't researched vin#) Anyway gas in the tank was beyond nasty!!! I drained and refilled the tank with new gas, saw it had oil in the reservoir, topped it off with new two cycle oil and tried to fire it up. (Bro-in-law says it ran great since new and pulled it in garage and shut it off. There it sat until I picked it up).

No go as expected. It cranks a few times then pops the fuse under the fender. I pulled the spark plug and it is very wet with oil (could be some fuel in it too, but looks pretty much like oil)

I drained the bowl on the carb and what looked like straight oil ran out. Pulled carb and found all jets plugged, a general nastiness to the carb. I soaked the housing and parts overnight in carb cleaner and sprayed all ports with compressed air (no rubber parts left in the carb cleaner). The next day the carb still had a "film" that wouldn't come off. I wasn't completely happy, but put the carb back together and re-installed.

Tried to fire it up and again a few cranks then pop the fuse, after a few times of resetting, the cranking got better, less fuse popping. Gave it a shot of carb cleaner in the intake throat of the carb and it fired up! Smoking like a ****. Rolled it out of the garage to run a bit. Neighbor asked if I needed 911 for my house on fire

I put it up on a block to let the tires be off the ground and ran it wide open. It runs good and strong but shoots oil droplets out like crazy. Also a good amount of white smoke. I took it for a ride around the neighborhood a bit (probably about a mile or so) runs good even at WOT (I've always heard two strokes like to be rode hard).

Now it starts easily but hesitates/dies on acceleration. I figure this is from nastiness in the tank sloughing off during the ride and re-plugged the jet or a passage in the carb. I'll be tearing it down/boiling carb tomorrow.

My bigger issue is the oil spraying. this looks like a new problem as the quad is clean except for this new oil (no evidence of this being a problem from day one). After a bit of web searching and I'm wondering about the following: 1)the oil is old/contaminated, 2)Possibly original owner put motor oil in the reservoir not knowing to use two stroke oil and thus it is not burning well. 3)I topped underseat reservoir to the top mixing new and old oil, now I'm reading too much oil in that reservoir might cause pressure problems. My plan tomorrow is to drain the oil reservoir and refill with new two stroke oil--maybe only filling half way to prevent a problem.

What are your thoughts I realize these will never run as clean as a 4 stroke, but an oil covered rear of quad doesn't sound right. It seems to me there is WAY too much oil in the cylinder head area.

Thanks for the tips!

 

I would be very careful on a bike sitting this long, especially since it's oil injected (Most Likely)

You need to be 100% sure that the oil injector is spraying oil into the carb, or just completely remove it and premix the gas. If oil is spraying that may tell you oil is not getting into the fuel and you are running lean. Could be plugged somewhere from years of neglect. YOU WILL BURN YOUR MOTOR UP if you ride it without the proper oil ratio.

My vote is buy the block off kit and just get rid of it. Much safer



I have heard of people boiling their carb with good results if it is really bad. Compressed air and carb cleaner are your friend. Wouldn't hurt to replace the jets while you are at it just to be safe.

I am sure LT80 will chime in shortly....

 

I agree w/wildcard.
I will add:
Smoke: I think the pipe has oil/oil residue in it. The carb/cylinder did right...
Remove the bolt in the bottom and see if that helpd blow it out.
If not, you can remove the pipe, heat it up and blow the crud out. There are plenty of posts on that.
I agree that new oil wouldn't hurt. Just better to make sure it's good.
Pre-mix is what I recommend also.

It sounds like you have a good grasp on what to do.

 

Thanks for the replies. I didn't get into it as much as I had hoped yesterday. I opted for a new carb kit, mainly for the needle & seat, but new jets have to be a help too. I also realized when I disassembled it before I missed the jet needle. So that probably is still gunked up.

I also ordered a true on-off-reserve petcock because I don't feel the love for the vacuum operated one. I picked up an inline fuel filter yesterday that I will install.

Before I saw "LT80"s post I pulled the bolt on the bottom of the spark arrestor and a fair amount of black dirty oil dripped out during the day. I thought about having a pipe bbq session and likely will go that route to get the oil out...and the neighbors thought they saw smoke the other day LOL!

I drained the old/new mix of oil out of the tank last night and while it still had a blue tint to it from the oil I put in, it was pretty dark. I refilled it (half full only this time so as not to overfill it). I'll save the pre-mix option for down the road as I'm pretty confident this pump is working. I do realize the consequences if I'm wrong though. My newly acquired service manual gives instructions on how to test it out.

I think I have access to a compression test kit, I've got to do some checking though. The quad has had pretty low levels of use and nothing hard core, but a compression check would make me feel at ease...unless its low!

My parts should be here by the weekend, now if I have time to wrench on it...

Thanks for the ideas guys! I've been browsing this forum like crazy getting on top of the learning curve on these little quads! It sounds like they are great fun! We've been loving the chinese 50. Its great for pulling sleds in the snow in the backyard...well snow less than 4" anyway! Can't wait to take both of these out in the mountains this year!

 

Problem fixed! *Cliff notes cleaned/rebuilt carb, smoke levels normal*

Thanks guys for the ideas and tips! I was able to get some wrenching time in yesterday. When I went to pull the carb I noticed the mounting bolts were very loose allowing the carb to move quite a bit on the intake manifold. I assumed a huge intake leak was there. Likely the bolts loosened up during my test ride

I tightened them up, pulled the choke, hit the start button and it fired right up. When I took it for a ride it would hesitate/die at off idle to about 3/4 throttle without choke, slightly better with choke, but not great. I figured I still needed to go through the carb again.

I pulled the carb and the jet needle had a bunch of sandy/gritty crap all over it, the main jet had re-plugged with some crap as well. I tore the carb down, boiled it for about 30 minutes, followed by carb cleaner sprayed into it, dried with compressed air. The carb looked very clean. The carb kit I bought didn't have a new jet needle so I cleaned and reused the original one. I reassembled, using new parts as possible. Changed out the OEM fuel valve for an ON-OFF-RESERVE valve and added an inline fuel filter after the valve.

It fired right up, almost with the touch of the start button, with the choke on. I let it warm up for a couple of minutes and took off down the street with choke off. I ran it around for a couple of miles, reset the idle, turned the fuel valve off, ran it till she died.

I didn't get around to pulling the exhaust pipe and cleaning, but I did pull the drain plug on the arrestor, propped the front of the bike up on a jack stand and let it drain for about a week. Quite a bit of nasty black gooey oil ran out. Now exhuast has the typical two stroke color/smoke levels.

Now to get it registered so I can run it in the mountains and see how it goes!

 

Well back to the drawing board...

I took the 80 out for a ride in the mountains last night. It would start fine and run good with choke, but would die after about 10 seconds or so without choke, even when warm and riding it. As soon as you would pull the choke back on it would run good again. Any ideas?

I'm confident the carb is clean. Last week I boiled it, rebuilt with all new components from a carb kit except the throttle needle(didn't want to unclip and change it). Put in an "on-off-reserve" petcock and inline filter. I'm wondering if it has an intake leak at the o-ring? I'll need to check that. I also need to compression check it. Anything else I should look at? I suppose I could pull the carb again and take look at the jets again. I left the o-ring out between the main jet and jet needle, also took of the boot that covers both jets in the bowl. I didn't change the float level, but could that be an issue? Could it be an air leak on the airbox side letting too much air in?

Any suggestions are appreciated

 

Let's see what the compression is and go from there.

 

Well, as you've said before this type of problem is a carb problem.

I thought no possible way it was the carb so I checked the compression. 115 @ WOT. Changed the plug, started the bike, checked for intake leaks-found none. Checked the air filter. It was clean.

Finally I pulled the carb. all was perfectly clean, checked the pilot jet last. Sure enough it was plugged. I removed the pilot, shot some carb cleaner through it, reinstalled and started it up.

After an initial choke to start it ran perfectly without choke, made a couple of WOT laps around the block considered it fixed. Turned off the petcock, idled it until it stalled out.

Now I'm just waiting for the weather to warm up to take it out for a ride!