Spark plug dies on cr125

[dirtryyder]

I just bought this Honda cr125 -2003mod.
At first I had a problem with overflow, so I clean'd the carb. And got it running again. Then this problem with the spark plug occured. After running about 30-60mins on a brand new BR9EG. The spark plug dies, and shows no signs to an electric spark. I replace it with a new one, and the same thing happens. Does anyone know what the problem can be?

 

[sharky243]

What are you gapping the plug at ? what fuel ratio are you mixing at ? are you lugging the bike ?

 

[dirtryyder]

What are you gapping the plug at ? what fuel ratio are you mixing at ? are you lugging the bike ?

I'm quite 'new' in the motocross world. So i dont have clue about those things. Is this something I can check on my bike? I'm not lugging the bike by the way.

 

[OriginalRider]

sounds like a jetting problem or mixture/air screw could be off.What kind of mods are done to the bike?

 

[dirtryyder]

Only mod that's done is a aftermarket silencer. I have tried changing the position of the mixture/air screw. But the bike act's the same no mather what position it is in.

 

[sharky243]

On the end of the spark plug,(the part that threads into the cyl. head) there are 2 electrodes. 1 is the center one, the other is the ground electrode. The ground electrode is adjustable by bending it to open or close the gap between the 2 electrodes. There is a spec. for this gap. Usually it is around .024" on most bikes. The plug gap should be adjusted to this spec. Be sure to check your book for the proper gap. The fuel mix ratio is how much oil to how much fuel. Most bikes take a 32:1 mix. Make sure you are mixing the fuel correctly, and ensure that it is fresh premium grade.

 

[OriginalRider]

sparks plug for dirtbikes are already gapped.ride your bike for about 30mins or less and check your plug if its burning black and its wet like mine is then its the jetting.

 

[_JOE_]

Chances are your needle clip position is a bit rich and possibly the pilot as well. Here's a good procedure to follow to get it running right......http://www.dirtrider.net/forums3/showthread.php?p=1340315#post1340315

 

[Beivakongen]

Only mod that's done is a aftermarket silencer. I have tried changing the position of the mixture/air screw. But the bike act's the same no mather what position it is in.

And i think you have a anoter reedvalve to.......

 

[OriginalRider]

I dropped my jet from a 185 to a 180 then put the clip on the 2nd position from the top and its runs 1000% better

 

[weav6385]

Heres some good info for ya.


Air screw adjustment- Turn the air screw all the way in, then turn it out 1.5 turns to start. Start the engine, and turn the idle screw in until you get a slightly fast idle. Turn the airscrew slowly in, and then out, until you find the point where the idle is fastest. Stop there.

Correct pilot jet?- If your air screw is less than 1 turn from closed, you need a larger pilot jet. If it is more than 2.5 turns from closed, you need a smaller pilot jet.

Tuning air screw- At full operating temperature ride the bike, using closed-to-1/4 throttle transitions. Turn the air screw slightly in either direction until you find the point that gives you the best response when cracking the throttle open. Most bikes are sensitive to changes as small as 1/8 of a turn.

Needle settings- Mark the throttle grip at 1/4 and 3/4 openings. Ride the bike between these two marks. If the bike bogs for a second before responding to throttle, lower the clip (raising the needle) a notch at a time until the engine picks up smoothly. If the bike sputters or sounds rough when giving it throttle, raise the clip (lowering the needle) until it runs cleanly.

Main jet chop test- Start the engine, and do a full-throttle run down the straight, through all gears. As soon as the bike tops out, pull the clutch in, and kill the engine, coasting to a stop. Remove the plug, and look deep down inside the threads, at the base of the insulator. If it is white or gray, the main is too lean. If it is dark brown or black, the main is too rich. The correct color is a medium-dark mocha brown or tan.

 

[Rich Rohrich]

Heres some good info for ya.

If you are going to cut and paste the words of someone else, you should give credit to the source in your post. Even though it's going full circle because you are cutting and pasting the words of a well known plagiarist will still take a dim view of the practice.

 

[weav6385]

Not sure where I got it. Its not an exact copy either asswipe! I put this together for my own reference. Nothing illegal here as they are not the exact words or fomat nor was it copyrighted! Sorry for trying to help out smart ass.