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My back plugs keep fouling, I pull um out and clean um and bike runs good for about 10 min, it slowly start running like craps, so I pull the plugs and clean um and it will run better for a bit,

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  • UM Master
  • 46,580 Answers

Hi, Shawn I would really love to help you but due to the magnitude of yesterday's solar flare the batteries in my crystal ball are dead and my mental telepathy headset circuitry was melted. I need the year, make, and model of your motorcycle please click on the word "COMMENT" below and provide this information in the box that will open and then click on the green comment box in the bottom right-hand corner after it posts I will receive an "ALERT" icon that will allow me to respond to your information.
Good luck and have a wonderful day.

Posted on May 06, 2017

  • 2 more comments 
  • Shawn slusher May 06, 2017

    It's a 2001 Honda sabre 1100

  • Shawn slusher May 06, 2017

    I've changed my stator,checked out my rectifier and put new plugs in and when I get on the interstate and pour the coals to it ,it wants to studded and backfire.

  • Shawn slusher May 06, 2017

    I have to find the sweet spot for it to perform right..

  • Gregg Mahin
    Gregg Mahin May 06, 2017

    Hi, Shawn and the usual suspects are:
    1. Fuel mixture too rich or enrichner left out too long.
    2. Faulty spark plug.
    3. Incorrect spark plug for the engine type or service.
    4. Piston rings badly worn or broken.
    5. Valve guides are badly worn and/or seals worn, crushed or have come off the valve guide and are pumping oil through it.
    6. Spark plug cable weak or leaking check for spark jump in the dark.
    7. Faulty ignition coil.
    For more information about your issue and valuable "FREE" downloads that you will need please click on the blue links below. Good luck and have a wonderful day.



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Posted on Jan 02, 2017

  • 14036 Answers

SOURCE: runs rough and keeps fouling out new spark plugs

plugs could be wrong heat range they could be too cold make sure you have right heat range.if all is good.replace air filter.have injectors tested they could be leaking when you turn engine off.have charcoal canister check.check fuel pressure regulator for rupture diaphram.if all is good.scan it check egr valve.if stuck open a little it will cause rough running foul out plugs.

Posted on May 29, 2009

  • 50 Answers

SOURCE: wondering if 93 octane in a 250 honda nighthawk is

try a hotter plug

Posted on Jun 04, 2009

  • 7 Answers

SOURCE: my rm 125 was running good for 45 min then it

clean your carburator, and if possible do a compression check, how longs it been since you replaced rings and piston.

Posted on Jun 23, 2009

  • 1187 Answers

SOURCE: 87 325 runs good when

It's the automatic choke!

The choke is "closed" or barely open... When cold, the engine needs a RICH mixture (more gasoline, less air). When the engine warms up, it requires a LEAN mixture (less gas, more air).

It is probably creating BLACK tailpipe smoke ... that means unburnt gasoline. (Blue smoke is OIL, white smoke is WATER).

Put the parking / emergency brake ON.
1. Remove air cleaner assembly from intake, use a carb cleaner spray or throttle body spray cleaner and spray just a little. (AutoZone $5)
2. Find the accelerator2.gif arm under the hood.
3. start car, rev the engine to make sure how to operate the accelerator from under the hood.
4. Carefully spray into carb / throttle body and work the accelerator ... don't let the engine die...
5. Watch out for "backfire"... it may create a small flame out of the carb. It will extinguish itself in one second.

6. You may need to do this two, three times.
7. Add a "complete fuel system2.gif cleaner" to your next tank of gas ($8).

That's it! ... pretty cheap, too.

Hope this helps!

Posted on Sep 04, 2009

  • 62 Answers

SOURCE: Shuts off spits and sputters

Check for vacume leaks first. Rubber lines..gaskets to carbs ect. Also remove and blow out your fuel line to tank and change out filter. Hope this helps.:)

Posted on Sep 08, 2009

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1 Answer

My 04 harley night train keeps fouling plugs left and right i richened the mixture with a 52 pilot jet. ran fine for awhile then fouled again could this be an electrical problem?

A #52 pilot is a bit on the rich side in my opinion. I usually use either a #48 or a #50 but each machine is a bit different and your location effects it as well. I wouldn't think an electical problem is the cause or you'd notice erratic engine performance prior to the plugs fouling such as misfiring, coughing or spitting back through the carb. How long are you running the enricher when cold starting the engine? This is the biggest reason I see for fouling plugs. People will start the engine with the enricher and allow the engine to run while they put their riding gear on, sometimes five minutes at full enrichement. This will foul the plugs quickly. The enricher uses a different fuel circuit than the normal running operation uses. It draws fuel directly from the float bowl and it's a very rich mixture. Try starting the bike with the enricher and once you can keep the engine running with the throttle, turn the enricher off. Use the throttle tension knob underneath the throttle to hold the throttle open enough to keep the engine running until it warms up.

Good Luck

Sep 03, 2011 | Harley Davidson FXSTB Night Train...

1 Answer


What is causing the fouling? Engine oil? On a two cycle dirt bike, the fouling can be caused by excessive oil in fuel mix. I believe 50 to 1 is the correct ratio yet you may want to cut back, a little at a time, on the oil or run hotter fuel. The exhaust system will also accumulate enough oil sludge to impede the exhaust flow causing poor performance and plug fouling. A two cycle must breath freely to keep itself internally clean. Air cleaner to exhaust. Proper fuel mix should have little , very little. Good Luckand hopefully this helps you.

Dec 27, 2010 | 2003 Yamaha YZ 125

1 Answer

Idles high and misses when cold. after you run it for a while it runs normal

You didn't say whether your bike was fuel injected or carbureted. A fuel injected bike or a carbed bike with the enricher pulled out will idle high. It is supposed to. Now, it should not miss though. It might be time for a new set of spark plugs. The enricher runs a very rich mixture and will foul a plug if you run it too long. I always tell people to only run the enricher just long enough so you can keep the bike running with the hand throttle. Turn the enricher off as soon as possible to prevent fouling a plug. If the bike is fuel injected, you'll have to take it back to the dealer to have it adjusted.

Good Luck

Jul 25, 2010 | 2003 Harley Davidson FLSTC Heritage...

2 Answers

What spark plug should i run in my 2003 YZ 125?

Run a B9ES if you don't have a problem with fouling. If you do have a problem fouling, run a B8ES. Both of these plugs are available at auto parts stores for a few bucks each.

The stock plug was a BR9** - the R indicates a resistor plug which is not needed.


Jun 18, 2010 | 2003 Yamaha YZ 125

2 Answers

2000 yz125 keeps on fouling out plugs

Fouled plugs are typically caused by jetting that is too rich. This could also be from a dirty air filter which can make the bike run rich. Clean up your filter and see if that is it. If the filter is not too bad, you might want to drop a size on your pilot or main.

Another possibility is poor compression - this can make a 2-stroke run richer than normal as the fuel can not be burned properly. Rings don't last long in these 125s. I used to re-ring each week when I was racing 125s.

You might want to run a B8ES plug, too - this is one step hotter and will help the plug from fouling as often.

Feb 01, 2010 | 2004 Yamaha YZ 125

2 Answers

My FZR600 won't start. No mods, all stock. I got it a month ago and it had been stored over the winter with no stabilizer. It wouldn't run, so I cleaned out the tank, made sure the fuel lines were clear,...

These things are really temperamental.The plugs are fouled again..I had the same bike and went through the same thing..It doesnt take much to foul them..Get some new plugs and she'll run like a beaut..Just remember not to choke it to much..Thats where the plug fouling happens the most..Always keep a spare with you and you'l always be on the good..It will work!!Have a great night!!!!!!!!

Apr 03, 2009 | 1989 Yamaha FZR 600

1 Answer


These tiny spark plugs will foul easily just from normal choking or even in-town riding at low throttle. Sounds like one or more cylinders drops out at times. Pull and clean the plugs, especially inners ( #2 and #3.) The sooty look is not far from a misfiring condition, so get them good and clean. Sometimes spraying firing tips with carb cleaner and then burning them with an oxygen/acetylene or other type torch can help bring back good firing metal. Unless you have a clogged carb or jet from dirty fuel or running without air filters. I bet the bike comes to life at higher rpms right? Fouling plugs. Numero uno cause for this symptom. THanks TT

Feb 11, 2009 | 1997 kawasaki ZX-7R

2 Answers

Running poorly

Not much to go on, but I would say carburetor issue. Have they ever been rebuilt, have they been balanced recently?

You can look at a manual here, hope it helps you -

Jan 09, 2009 | 1983 Honda GL 1100 Gold Wing

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