Need advice for 2000 Suzuki King Quad 300 carb/motor issue

[munchman155]

Hi all, I couldn’t find any help searching for “flooding”, so I hope this new post brings out the best in your knowledge of 2001 Suzuki carbs . Here’s my ATV’s story:

After it was sitting for a couple months, it took a lot of turning-over and full choke to get it to run, which wasn’t normal, but finally it started and I puttered off down a nearby trail. After about five minutes of slow riding, at the dead-end of the trail (of course), the engine faltered, sputtered, died, and would not restart, choked or not. Just like running out of gas, but I had plenty. Different fuel petcock settings didn’t help. It was a long push back.

Air filter is clean, screen at air entry is clear, spark plug is a little dirty but was working, gap is perfect. I removed the carb diaphragm cover (#1 on the carb drawing at <a href="http://www.bikebandit.com/2000-suzuki-motorcycle-ltf300fy/o/m6475" target="new">Bike Bandit</a>), pulled the “vacuum piston/diaphragm assembly” off the top (#’s 2-4), and found the chamber under it, where the #12 jet needle pushes down into a seat, half full of fuel.

After I checked some oil levels and removed and replaced an inspection plug on the front bottom of the carb, the fuel puddle in the carb was now gone. Maybe it leaked down into the exhaust? I put it back together and it started with choke, with very white exhaust that dissipated normally—extra fuel, I guess. As it warmed up and I backed off the choke, it only stayed running if I kept on the gas, which made lots of white exhaust (maybe just because it was fairly cold). It got harder and harder to keep running, and finally I let it die. It won’t restart, and there’s a puddle of fuel in the carb chamber again.

Next I pulled the carb completely out, removed all three of those brass jet port things (pilot jet, etc.) on the bottom of the carb (one at a time!) and blew them out along with the ports they screw into (didn’t have carb cleaner on hand); they were all clean and I could see through all the holes. Float is beautiful, no fuel sloshing around inside, float pin shiny and clean, float moves the needle smoothly. There was very little crud in the bowl, just a little red resin/grit.

There was a tiny piece of hard resin stuck above the needle valve, and I was certain that was the cause of the flooding. Neither the float needle nor the long jet needle (#12 on the BB diagram) connected to the vacuum diaphragm on top looked abnormal. I put everything back together, it started right up even with an empty bowl, and it idled great. Thought I had it licked. Took it for a spin, this time back and forth past my driveway instead of down a long dead-end trail . It ran awesome and made lots of mud…for about five minutes, at which point it started choking. Gooosing the throttle kept it going long enough to drive back into my shelter/garage. Took the carb cover off, pulled the piston valve and diaphragm off, and the bowl was full of fuel again.

A suggestion I’ll pursue next that the fuel petcock might have a hole; after that, I might replace the vacuum needle (#12) and seat. I’ll also add a fuel filter, as apparently this rig doesn’t have one (save $1.50, kill an ATV—I don’t get it). I’d guess the fuel pump should be fine, seeing how quickly it got the rig started with an empty carb bowl.

It only has about 1300 miles on it and was running like a champ last time I had it out, when it started easy, warmed up and idled quickly, and ran great. I can add photos here if that'd be helpful.

I can fix most things I put my mind to, but I'm don't have much experience troubleshooting a carb problem—if indeed it even is the carb, and not vacuum-related or something else. Your seasoned advice (and guesses) welcome!

Many thanks, Eric

Edited April 7, 2010 by munchman155
Correction of year, 2000 to 2001

[DirtDemon]

First thing I would do is drain and clean the tank and petcock. Then check the float adjustment, and plunger. If the float is improperly adjusted it may be letting too much fuel in the bowl hence the fuel in the carb body. If there is any crud built up on the stopper causing it to stick, or it is not seating properly, fuel will still flow into the float bowl causing it to flood. What part of Washington are you from?

[munchman155]

Many thanks, I'll pursue those and let you know how it turns out.

[DirtDemon]

Good luck to you, I hope you get it figured out man. Again, what part of Washington are you from, I live in the Bonney Lake area.

[munchman155]

Per some good advice in reply to this same plea on Craigslist, I pulled the carb for a cleanout. Everything was beautiful, but found one tiny fleck of varnish stuck above the float neede. Put it back together, it ran another five minutes, and then flooded full again. Cleaned carb again, found another fleck of varnish, and this time heeded the good advice correctly and installed a $2 inline fuel filter. Back on the trail! I highly recommend all fixers get a Clymers for your ride (try Half.com, great deals there, or amazon.com) and use the OEM parts listings at bikebandit.com for detailed schematics of every minute part you hope will never fail. Ride on! Eric

[munchman155]

Oh, Dirt Demon, I'm east of Renton, south of Issaquah. I'm planning on picking up a slighly smaller ride soon for my son so he can enjoy riding and I can keep a comfortable eye on him and his friend from my own seat, not jammed half on the back of mine :-).

[DirtDemon]

I'm sure your boy will like having his own ride, I know I enjoyed my first quad. My dad used to scare the crap out of me riding with him. A word of advise, a used name brand machine is a much better idea than a cheap knock-off. I have a friend who has bought three cheap Chinese quads, and has had nothing but problems with all three of them. My boss lives out near you, he is off of May Valley road. I used to do a lot of work out that way too, I always saw this fellow out on the side of the 900 giving the peace sign to everyone passing by.

[munchman155]

Agreed on the China principle. Picked up a 1986 2WD Yamaha Moto4 for $1100. Came with manual and helmet that fit my son perfectly (China's best!). See pic at http://www.munchworks.com/images/QuadBoy.jpg. Fenders to keep the mud at bay, lights for the ride home at night, and best of all, starts and runs like a champ--doesn't even need choke to start!

[munchman155]

Hi DD, I had too much free time so I bought another King Quad to work on for my girlfriend :-). Mine was actually an '01, hers is an '00, also a 300. Because it was it wouldn't idle after the choke is off and was backfiring sporadically, I pulled the carb and gave it a general clean-out and compressed air blow, plus adjusting the spark plug gap (which was way to small). Backfiring is gone, but even though it still starts right up on choke, if you close the choke all the way, it dies. I'm thinking it needs some carb adjusting, which I'll need to get help with because I can't find a manual for this, an LTF300FY. The closest manual I find addresses the 250 and the carbs are different. Is there one adjustment that would solve the choke-killing problem? Thanks! Eric