2000 Suzuki King Quad issue

[Quad king]

I am not sure what is wrong with my King Quad. I had a new carburetor put in 6 months ago, just replaced the fuel pump and added an in-line fuel filter in. I have been trying to fix this quad for a while now and do not know what is wrong with it. It idles fine and runs great as soon as it is fired up, you can Rev it and stay in first gear with 100% power. As soon as I drive 10 feet it looses all power, I mean it is sputtering and doesn't move at all, but when I let off the gas after it sputters it idles fine. I will attach a video of what it is doing.

[Ajmboy]

Sounds like it’s not getting fuel on rev. Have you messed with the fuel petcock?

[Quad king]

Yes. The fuel petcock looks good. I took the spark plug out to find its running very rich. I am attempting to adjust the carburetor mixture screw. Any advice on how far I should turn it?

[davefrombc]

Did it run OK  after you had the carb replaced? The  air screw usually  is out  about 1 1/2 turns +/- from lightly seated .  If this has been happening since you got the new carb it may be the  main  fuel  metering rod   is set wrong .. There  are notches in the top of it and a clip to  change the amount it rises as you open the throttle. If  the clip is in the lowest setting the carb will run the richest  and in the top  notch , the leanest. If this  has been a problem  right from the start with the new carb , try setting the metering rod one notch down from the top.  That's where the rod is et on  a friends  Suzuki  that  uses the same carb..

[randy02136]

I have the same exact bike, same kind of problems. Mine has new replacement carb last spring (2020) runs fine idles good, run thru the gears. But after a few miles and it gets hot it turns to crap. It will stall if you don't keep giving it fuel and kind of loses it's HP, doesn't seem to run right and you have to park it.  I think it's the choke thing. The replacement didn't fit exactly and I couldn't get the choke cable to sit right.
The Big problem is you can't get at the carburetor with out dismantling the airbox. Not even to make idle adjustments. And even then it's extremely hard to access.
Time for a new one after 21 years. 
Any suggestions for a new quad?

[Quad king]

Hello. @davefrombc The carb was fine once it was replaced, I rode it for about a year and now this issue. Over the past couple days I have been working on cleaning the carb and messing with the mixture screw. The problem with all of this is you have to take the carb and airbox off in order to even look at the mixture screw. When I took the carb apart and cleaned it, I made note of the mixture screw position, it was 2 1/4 rotations to be screwed in all the way. Once I set the screw back to its original position I re-assembled the carb, threw it in and still got the same issue. When I had the carb replaced the first time I had it tuned by a shop. Now that I have cleaned the carb, I have been doing test runs with only turning the mixture screw clockwise 1/2 a turn at a time. I ended up getting that screw half a turn away from being screwed in all the way and the problem has not been fixed. Is the next step to put that screw back where I found it and adjust the main fuel metering rod? I am new to carb issues, but am trying my best to solve this issue. 

 

@randy02136 I am not too happy with this issue and I feel your pain about having to take the airbox and the carb off in order to make any type of adjustments to the carb.

Edited February 7, 2021 by Quad king

[Hunter19]

I had a similar problem I have a 1998 king quad the quad idol perfect as soon as I gave a little gas the quad with spuderd and it had no power took the carburetor off cleaned it put it back same problem. I checked the petcock and clean that too still had the same problem. I drop the machine off at ATV dealer and motorcycle dealer they found the problem the problem was electrical it was the rectifier I would’ve never found that problem out I would’ve bet my life that it was the carburetor or a fuel problem. 

[davefrombc]

I believe  that was a similar problem another member in the forum  had with his quad. Idled well and ran  ok under low load but as soon as he tried to rev up  it would cut out.  You  can get  inline spark  checkers  that will tell  you  if you are losing  ignition  under load. Here's a link to  one  Home Depot carries.   You can  likely find one in a  local auto supply or on Amazon.  If the carb ran  fine when replaced then the settings were likely  fine.  Plugged passages from sitting  usually  means a lean run  problem.  Hunter  may very well  have set the right course for you. . Not all  apparent fuel problems are carb related,  but like most  that's the first thing I  blame too.

 

[Quad king]

Thank you guys. I will try looking into the rectifier and see if that solves the issue. I will keep you guys updated @davefrombc and @Hunter19

[Mech]

Simple things first.. You could try a new spark plug.. that black/rich could be caused by it misfiring. Misfiring could also be caused by some other electrical problem as has been said but those things need diagnosing and are dearer to fix..

The idle mixture only effects idling and a tiny amount of throttle, after that other jets take over. You should check the air-cleaner, and also, those things have an auto fuel cutoff tap which plays up sometimes and lets the sump fill with petrol.. check the oil level.. If it's too full, or if fuel seems to be disappearing out of the tank, check the fuel tap mechanism.

Do a standard tune, plug, aircleaner, valve clearance, then start to diagnose it. If you have a timing light it's an easy test to drive with it connected and watch to see if the spark starts disappearing as the faltering starts

[Avery Johnson]

Sounds like a wiring issue to me. A short somewhere. Check and clean your negative cable where it hooks to the motor (ground). Hope that helps. 

[Dirty]

Were you able to fix the problem? It sounded like a rectifier or electrical issue to me and wanted to hear the outcome to verify if my hunch was correct.

[Hunter19]

Ok I had the same problem rebuilt the carburetor check the fuel pump put all kinds of fuel additives in there and I couldn’t fix it. I threw in the towel dropped it off add an ATV place they worked on it it turned out to be the rectifier it was an electrical problem they replaced it and it’s running like a charm. The rectifier  is located in the front of the bike under the handlebars behind those louver slats if you can get at it look at it look at the back of it see if there’s any damage mine had a bulge in it and it was cracked.