Suzuki King Quad 300 Running Problems

[lanow]

Hi Everyone,

I am new to this forum and hope that someone out there can help me, I have an early Suzuki King Quad 300 (280cc) which starts intstantly every time but at about half revs or there abouts it starts spluttering and will not rev any higher, this fault is present whether choke is applied or not, some one suggested that silencer maybe be clogged so removed baffle but no improvement have removed carb and stripped 3 times but still no joy.

Any ideas would be most welcome.

Cheers Rob

[racers]

unplug rev. switch try again. check air filter, Check ALL carb vacuum ports and lines including tank vent are clear,Clean carb 4th time , Just a few houghts good luck

Edited November 23, 2011 by racers

[quad_king_300]

fuel tank petcock diagram is broken. and sucking fuel as some as you rev it. check it for a rip or whole. common problem. easy fix is to block the vacuum line. the side fuel pump is good enough.

[Ajmboy]

What year is it? Sounds like the bowl is starving for gas and full throttle.

* Re-worded title for searched. Added issue.

[ezlife]

What year is it? Sounds like the bowl is starving for gas and full throttle.

* Re-worded title for searched. Added issue.

Same problem here. I believe its electrical though. If I hold the starter button down and rev the bike it revs up fine. Sometimes it will start and rev fine for a few minutes and other times it will rev once and then act like its a limiter. I seen you posted to disconnect the rev wire. Where about is this located? I didnt see any safety switches to trace back. Thanks

[ezlife]

So after messing around with the atv I found that if I turned the igntion forward another click so the headlights would come on it would stop stumbling. Took it out for a test drive and it started the problem again. Changed the ignition which did not help. Checked charging found that its charging at 17 volts. Looks like regulator rectifier. I"ll let you know as soon as I swap it out.

[Ajmboy]

So after messing around with the atv I found that if I turned the igntion forward another click so the headlights would come on it would stop stumbling. Took it out for a test drive and it started the problem again. Changed the ignition which did not help. Checked charging found that its charging at 17 volts. Looks like regulator rectifier. I"ll let you know as soon as I swap it out.

Good to hear you have a direction and diagnosis made! Good Luck!

[JustRandy]

Hello. This is a neat little forum and every thread I see has replies with reasonable answers, so I signed up in hopes of getting to the bottom of my 300 king quad problems I was using another forum, but it seems I'm the only guy answering questions over there lol. Anyway, I'm having trouble similar to the OP. It just seems the carb isn't getting enough gas.

Thanks to oxidized_black, I was able to get the service manual and I set the float just over .5 inch (It was way high). I noticed when I pressed on the float, before it used up the spring inside the needle, the float would hit the carb body. That didn't seem right to me so I left it at that setting without going fully to .5 inches as the spec said. I've also installed a 40 pilot jet in place of the 37.5. I've installed a 140 main in place of the 120 something. Needle clip is per spec at 4 clip from top. All these specs seem odd to me. Usually carbs are set at 3rd clip (middle one) and mixture screw is 1.5 turns out instead of 2 5/8 like the spec says.

So even with all this richening, I'm still having to use the choke to idle and oddly enough, I'm having to use it more the hotter the engine gets! Which is making me think its something electrical. Only electrical things crap out with heat. But what could it be? And sometimes it will rev out nicely. Then I head for the road to see how fast it will go and it acts like the road scares it LOL! It acts like its out of gas. So I limp back to the yard fearing I'll be stranded on the road and it runs good again as soon as it hits grass. I'm baffled.

I had the petcock problem everyone else had and I bypassed that. I took the fuel pump apart and polished the corrosion off. There's no reason the pump shouldn't be working right.

Valves are set right, but engine is full of gas due to the petcock problem. Its not insanely full, but it is overfull. I've read this can cause problems, but its hard for me to imagine it would cause an engine to run lean. I don't want to drain it and refill because as soon as I get it running right, I'm tearing the engine apart. IE I don't want to waste 4qts of oil. Unless someone really really thinks it could cause big problems. I don't want to break in a new engine with carb problems.

Thoughts?

[marioweldinginc]

PM Cheriah as she is the official QC carb queen. She might be able to steer you in the right direction

Sent from my SGH-T989 using Xparent Blue Tapatalk 2

[JustRandy]

Update. My regulator was bad. Big crack in the back and bulging out. I swaped it. Now I have 14.3 volts, but no change in how it runs.

Ignition coil was at lower end of where it should be on ohms, but close enough I guess. I cleaned the grounding points.

I pulled that silly rubber strap off my gas cap and verified I have a good hole there so the tank doesn't develop a vacuum.

It seem nothing I do will produce a change in how it runs. Big jets, little jets,,,, it doesn't matter. Choke is always needed and sometimes it will rev and sometimes not. Sometimes it will idle nicely and then I sit down and just wait. A few min will pass and it will get slower and slower until it dies. Makes me think its rich. Well, why does the choke make it run better?

I need a priest. This thing is possessed or something.

Its funny because I'm usually the carb guy. I can take a bare carb body and figure out what fuel jets, air jets, needles, and slides work and do it with no airbox! I don't like to pat myself on the back, but just throwing that out there. This really has me puzzled though. I'm about to set a tank on the rack and gravity feed a regular carb just to see. I usually respect japanese engineering but those guys must have been hittin the saki hard when they came up with this!

[JustRandy]

I put a 26mm roundslide from a 230 quadsport on and gravity feed tank and it runs like a champ. I spent the day seeing what all this machine will pull lol. I guess I need to find a 28mm carb somewhere. That's probably about right for this engine. This is just another reason why I hate CV carbs. Too many things to go wrong with them.

[daren]

Is any one on here to help me on my 300 king quad it runs at a idle n revs at first then go to spuddering I can turn it off n back on n it runs fine then starts spuddering I have cleaned carb n all hoses n put a carb kit n and no luck any suggestions

[Denn34]

Sounds like the carb vent is blocked

[didntmakeit]

heres a little trick I figured out for hard starting atvs that seem to run but shut down and sputter out. If your having Backfiring through the carb, spitting gas out through the carb it maybe a bad intake valve not seating properly. To test this Pull spark plug out, move piston to TDC on compression stroke, Take some compressed air with a air nozzle in spark plug hole, make sure you can seal it to the hole so no air can escape. apply the air and listen for air escaping through the carb or the exhaust valves. that will determine if you have a bad valve. Best way to check for bad valves.

[William Harless Jr]

I have a 96 king quad 300 that idles fine and revs fine but seems to lose power once in gear... reverse is great though... but seems to lose all power once good and warmed up... please help

[William Harless Jr]

Oh and battery is being charged.. it's putting out 13.2v at the battery on idle and 14.4 or full throttle

[JustRandy]

1 hour ago, William Harless Jr said:

I have a 96 king quad 300 that idles fine and revs fine but seems to lose power once in gear... reverse is great though... but seems to lose all power once good and warmed up... please help

Sounds rich.  Check the fuel petcock if the diaphragm is leaking into the vacuum hose.  It's a common problem.

[Frank Angerano]

Wow a lot of carb/reving issues might as well put my two cents in!  I have had a few bikes do this. And to all the "carb specilist" as I feel I am lol to my surprise I have found that even though we clean, rejet, rebuild!!! There is or may be a blockage that still exists within an area you cannnot access!  I've been through this over and over and when I finally tried a new carb bang the bike fired right up and worked beautyful go figure. I have cut one carberator open just to see and found that these things have a lot more going on inside then we may think. 

Fuel peckocks and filters are also a major factor in this type of situation and are a major contributor to some of these fuel delivery problems but most likely time for a new carb. Yes it sucks but most likely will clear up a lot of issues by replacing the carb. 

Also I recommend monitoring the spark. I was pointed in the direction thanks to this site of a device that you can put in between the spark plug and coil wire to monitor you spark intensity and to see if any changes happen after the bike heats up. This will save you a lot of time in diagnosing weather its electrical or a fuel delivery issue.  And it's a cheap tool to buy. 

Lastly, take a look at all rev limiters these things suck! Over design and complicate things with the thought of safety (a good thing) but also are the culprit of a lot of backfiring and sputtering problems. 

Good luck.  

[JustRandy]

10 hours ago, Frank Angeranno said:

Wow a lot of carb/reving issues might as well put my two cents in!  I have had a few bikes do this. And to all the "carb specilist" as I feel I am lol to my surprise I have found that even though we clean, rejet, rebuild!!! There is or may be a blockage that still exists within an area you cannnot access!  I've been through this over and over and when I finally tried a new carb bang the bike fired right up and worked beautyful go figure. I have cut one carberator open just to see and found that these things have a lot more going on inside then we may think. 

Fuel peckocks and filters are also a major factor in this type of situation and are a major contributor to some of these fuel delivery problems but most likely time for a new carb. Yes it sucks but most likely will clear up a lot of issues by replacing the carb. 

Also I recommend monitoring the spark. I was pointed in the direction thanks to this site of a device that you can put in between the spark plug and coil wire to monitor you spark intensity and to see if any changes happen after the bike heats up. This will save you a lot of time in diagnosing weather its electrical or a fuel delivery issue.  And it's a cheap tool to buy. 

Lastly, take a look at all rev limiters these things suck! Over design and complicate things with the thought of safety (a good thing) but also are the culprit of a lot of backfiring and sputtering problems. 

Good luck.  

Good points!  Concerning carbs, I keep some guitar wire around for cleaning jets and small holes.  Chemicals don't do much.

Regulators are common problems on these machines and if it runs better with the lights on, that's the problem.  I bought the biggest baddest regulator Rick's Electronics sells because I fried 2 OEM ones.

Rev limiters can sometimes be improved by using an older CDI, but the problem with rpms is the weak valve springs.  One of the first models of these machines (250 model) had ovate springs which are super-stiff.  Zuki only used them one year and I forgot which year since that was 5 years ago for me.

If there are changes in the spark due to heat, then it means a coil somewhere has lost enamel due to age.  That is common on the 80's models 230 quadsports that start fine when cold but are impossible when hot.  Alternatively, cold starting problems could mean worn intake valve.

[JustRandy]

On 3/4/2016 at 7:38 PM, didntmakeit said:

Best way to check for bad valves.

The best way to check for bad valves is to find TDC at compression stroke and then wiggle the rocker arm.  If there is play, the valve is good.  If not, a new seat must be cut and new valve installed.

I've tried dozens of times to install a new valve in an old seat, but 100% of the time I've had to continually replace that valve.  It seems there is no way around cutting a new seat.

[Senque Bingham]

I have a suzuki king quad 300 4x4 and it starts up but when i go to take off it hesitates to go then it cuts off would anybody know why it's doing that

 

[spock58]

Those quads use a fuel pump in most models and can often fail. They can leak fuel and run really rich or do almost nothing and run dry - not always easy to notice the diff.

First thing to do though is change the sparkplug if you haven't already - it's a cheap fix for lots of quads!

[johniii]

great tips guys,thanks.

[Michelle Hodges]

I have a 96 300 King Quad and it starts and idles just fine but once you hit about 15 miles an hour or so that's as fast as it'll go no matter how hard you push the throttle I don't know where to start I was thinking clean the carburetor but I'm not sure anybody have any ideas where I should start.

[JustRandy]

16 hours ago, Michelle Hodges said:

I have a 96 300 King Quad and it starts and idles just fine but once you hit about 15 miles an hour or so that's as fast as it'll go no matter how hard you push the throttle I don't know where to start I was thinking clean the carburetor but I'm not sure anybody have any ideas where I should start.

Turn on the headlights and see if that helps.  If it does, it means the regulator is not regulating the voltage down and the CDI is not working when the voltage spikes as the rpms go up.  Regulators are notoriously bad on these machines, so don't replace with another stock one or it will happen again.  Contact Rick's Motorsport Electronics https://ricksmotorsportelectrics.com/ and ask for the biggest they sell.  It doesn't cost that much and will handle 50 amps.

If it's not the regulator, try swapping the spark plug.  It's not likely to be the problem, but I once torn down a carb only to discover the spark plug was the issue.  That sucked.

Since you said it idles fine and the pilot jets are the smallest, then I'm assuming the carb is clean enough, therefore it seems more like not enough fuel is reaching the carb, so I'd want to know the condition of the fuel pump and the vacuum lines.  That is another problem common to these machines.

That's all I can imagine that would produce those symptoms.  Maybe a clogged baffle in the muffler?

[Michelle Hodges]

Thank you for the advice I'm going to start going through those issues today

[Mike Tanner]

On 11/22/2011 at 3:10 AM, lanow said:

Hi Everyone,

I am new to this forum and hope that someone out there can help me, I have an early Suzuki King Quad 300 (280cc) which starts intstantly every time but at about half revs or there abouts it starts spluttering and will not rev any higher, this fault is present whether choke is applied or not, some one suggested that silencer maybe be clogged so removed baffle but no improvement have removed carb and stripped 3 times but still no joy.

Any ideas would be most welcome.

Cheers Rob

 

Could be over chraging mine was doing that i put a new rectifier runs good

[spock58]

It couldn't hurt to pull the air filter and see if anything changes - take it for a short ride and report back.

[Chris Meredith]

Hi everyone I have a 1993 Suzuki King quad 300 and I have a old battery in it and I just pull start it I noticed today that it sputter and back fired till I turned the key all the way over to the light does anyone know if I should get a new battery

 

[JustRandy]

20 minutes ago, Chris Meredith said:

Hi everyone I have a 1993 Suzuki King quad 300 and I have a old battery in it and I just pull start it I noticed today that it sputter and back fired till I turned the key all the way over to the light does anyone know if I should get a new battery

 

You need a new regulator.  It's a common problem on those machines.  I wouldn't buy another one just like the old one because it will fail too.  I called these guys https://ricksmotorsportelectrics.com/ and bought the biggest they had.  I think it's for a Triumph motorcycle.  It can handle 50 amps.

What's happening is once the voltage gets to 17-18 volts, the CDI stops working correctly which causes the sputtering.  Turning the lights on reduces the voltage to allow the CDI to work right... until you rev it up higher then the problem comes back, so you'll need more lights to reduce it more or a new regulator.

The regulator is on the front of the machine.  I cut the plastic to access it.  When you get it off you'll probably find the back of it is cracked.