Brand new cr125r died on me after 30 minutes, need help

[Tinbox1]

I'm pretty much new to riding so im not very smart on the subject. Anyways, I learned how to ride on my friends crf250r and I decided to buy an 07 Cr125r from the dealership. We take it home and we ride around the area,not riding it too hard (although im not sure about how hard my friend with the crf250 rode it when I let him test it), and about 30 minutes into riding I hear a few loud bang/crack type noises and then the bike died on me. It wont start at all, we even tried to run with the bike then pop the clutch to start it and it started but wouldnt rev and shut off again.

We called up the dealership and they said to check to see if the gas line is messed up but its not, and then the guy said to look at the spark plug. We take out the plug and sure enough the thing is completely black, i rubbed it down and got the oil off of it and then I sprayed it with carburetor cleaner. I put the plug back in and checked to make sure the bikes in neutral and the fuels on and still no luck at starting the bike, so later today we are going to go buy a few spark plugs and hope thats whats wrong.

However, what I want to know is why would the spark plugs foul this easily? I was in first gear putting around for only a small amount of time, and I payed for the dealer to rejet the bike before I went and picked it up. And if its not the plug, what else could it be?

And for my last question, as I said before I'm not too smart about the entire subject of two strokes or dirt bikes altogether, but is it normal for a new bike to have some oil in the silencer? Besides 1 drop on the swingarm the first time starting it, it never got anything on the swingarm again even when going much faster than the time it did. I also noticed that theres some spray on the inside fender next to the silencer, but im assuming this is probably normal for a new bike.

 

[longtime coming]

The bang/crack noises are confusing. The Cr125 is a great bike. We have an '06. You said that the dealer re-jetted it. Find out what they put in. I was lazy and just bought a JD kit and followed the directions. Then it still fouled plugs (probably your problem, but the noises..?..). The bandaid fix at that point is to go one range hotter on the plug. Ours has not fouled a plug since, except when we tried to go back to the stock plug. You cannot putt around on that bike or it will foul plugs. You don't have to go stupid fast, just give it large squirts of throttle every chance you get. Keep it in the sweet spot, shift, shift, shift and enjoy. You have a great bike there. The sweetest clutch I have ever used for one thing. And nice brakes. And the motor simply rips in the sweet spot. Short and sweet. Shift, shift, shift. Clutch, clutch, clutch. 125's. Wahooo!

 

[Tinbox1]

Yea im betting that it was my lack of skill and putting around without revving it that caused the plug to foul, I wouldn't say the noises were like, bangs from the exhaust type noise or something really loud, just stuttering like its skipping something and then it shut off.

But I think it was the plug just because when I would switch off with my friend, it slowly would take more and more kicks to start the bike. But when the bike worked it was awesome :)

 

[longtime coming]

Sounds like a fouled plug to me. Try a 1(and only 1) range hotter plug for a while. If the dealer got the jetting close, this should fix you up. The dealer will probably suggest the same. Congrat's on the great bike. Shift, shift, shift. Clutch, clutch, clutch. Wahooo! What I mean by clutch, clutch is: when that 125 falls off the power, you have two choices. You can downshift or lightly slip the clutch to get it back in the power. Depending on the situation, it is usually smoother to just slip the clutch for a split second once or twice and voila, the power is back. That CR picks it back up beautifully. Good Luck! Always carry a spare plug and a wrench with you (and a toothbrush to clean around the plug hole. Do not let dirt get in your engine (Rule #1). Be super careful when re-seating your air filter after cleaning (see rule #1).

 

[Tinbox1]

Ok cool thanks, but im not quite sure on how to know what the heat range of the plug is, the two recommended plugs in the manual are (standard)"BR9EG W27ESR-V" and (optional)BR9EV W27ESR-ZU

 

[longtime coming]

And check your spokes often for loose ones. And all the nuts and bolts on the whole bike. Be gentle, those little bolts strip and break easily. Use top quality premix oil. Learn how to do a top end job to keep it fresh (remember rule #1). Read your manual cover to cover. :ride:

 

[Blink-182]

dont they add a little oil from the dealership?

 

[Bigdogdaddy69]

you will find a Ngk br8es at napa. Thats what you need. The plugs the dealership list are expensive. The Ngk plugs run great and are cheap.

 

[nikki]

Ok cool thanks, but im not quite sure on how to know what the heat range of the plug is, the two recommended plugs in the manual are (standard)"BR9EG W27ESR-V" and (optional)BR9EV W27ESR-ZU

In my 125's, I always ran a hotter 8 heat range plug. My plug of choice was a BR8ES, which you can get at most automotive stores for around $2. If you're fouling the 9 plugs, then give it a try (as long as you aren't riding WFO for the majority of your riding).

As for the loud bang/crack noises, that doesn't sound good. If the problem isn't the fouled plug, and you can't easily figure it out, I would take it back to the dealer and have them look at it. Usually loud noises on a bike are something breaking, and you shouldn't have anything breaking on a brand new bike.

 

[Tinbox1]

Yea im going to give the 8 plugs a try, and if it still fouls I'll take the bike back to the dealership and get them to fix the jets again (SIGH) I guess I shouldnt have agreed to have them order new jets which made me wait to get the bike an extra week.

 

[Tinbox1]

I put in a new 8 plug and the bike started up first kick, rode up to third gear and revved it and almost no oil came out the back from what i noticed, So i know the noises I heard yesterday werent something breaking, only time will tell if it still will get fouled as fast (i found out the jets that the dealership put in were 410 Main,50 Pilot and the needle clip is on 2nd position). But it started on first kick both times i tried it while yesterday with the other plug each time I started it, it would take more and more kicks.

 

[_JOE_]

You need to learn to jet yourself. Jetting is SUPER important to the rideability of a 125. I would guess you were just simply not running the engine hot enough to burn the oil off the 9 plug. Run the 8 until you get comfortable with the bike. DO NOT run it for a long wide open run. It can cause pre-ignition if run at high temps which is BAD for the engine. Usually bikes are rich from the factory. What jets were stock in your bike? Did they actually ride the bike or just throw a size smaller jet in it? Jetting your bike is EASY! Do a search and some reading and you'll have all the knowledge you need!

 

[whenfoxforks-ruled]

How long of a break in did you do? Do you know how when the power comes on and the front end gets light, that is the optimum range it was meant to be in most of the time. Putting around is another story. The temperature is cooler and the excess fuel gets blown out of the cylinder, this is called spooge. Its a black oozing mess that serves no good purpose. Even if it is jetted rich and rode correctly, it will leave spooge. The spooge will clog your silencer packing and require replacement, and gum up the exhaust valve, and you will foul a lot of plugs. If you learn to read your plug, and jet your bike, it will not do this. Jetting changes, and it could get costly taking your bike to the dealer every day. http://www.dirtrider.net/forums3/showthread.php?t=48348, http://www.dirtrider.net/forums3/showthread.php?t=92818, And I sure hope you did the break in.

 

[Deadohiosky39]

He said something like the bang crack being more of shudder/Studder type thing. Which my guess would be because it was in gear and the tire locked up when the motor started to die. So I agree, it was probably just a fouled plug.

 

[rmc_olderthandirt]

I wouldn't re-jet until you have more time on the bike and bring your skill level up.

Two cycle engines don't like to "putt". If you are a novice and riding around nice and slow then the engine is not going to heat up to full temperature. With the engine running cold the plug will foul easier.

You could rejet the carburetor and compensate for this but in a few weeks when you start pushing the bike harder the jetting will be wrong again.

Switching to a "hotter" plug is an acceptable approach to solving the problem, it is not a "bandaid". A hotter plug will NOT make the engine run hotter, it will just make the plug run hotter. The plug needs to run hot, hot enough to burn off the gas, oil and combustion byproducts that get deposited on it. A hotter plug will allow you to putt around and not foul and still keep the carburetor jetted properly for when you do open her up and push it hard.

Later, when you are riding more consistently at a harder level, you may want to change back to a colder plug to avoid any pre-ignition, which could happen if the plug was running way too hot.

For what it is worth, I run BR8ES plugs on my bikes. I will still foul plugs when I am trying to ride slow with my wife on her quad. I have learned that I need to ride in circles occasionally to keep the plug from fouling.

Rod