Spark Plug HELL...P

[syko]

I am the new proud owner of an 04 KX125.
I had the bike on friday and i have been trying to utilise the weekend to break it in.

unfortunately i have encountered big problems!
this is what i have done so far...
I put a couple of litres of fresh fuel and oil, choke up and kicked her over, after about 10 or so kicks she fired up. i left her with the choke up idleing for about 5 mins till she warmed up.
she was a little bit dull sounding but i was expecting that. i switched her off and let her cool.
a whole load of black oil was seeping out the end of the silencer and dripping down onto the swingarm.
after about 30 mins i took her out the front of my house, fired her up, stuck her in first and rode around for about 15 mins in mid range of first gear. obviously i wasn't thrashing the thing. she was kicking out a whole lot of blue smoke and a whole load of iol was again seeping out the end of the silencer pretty much covering my mudguard and swingarm.
i switched her off and let her cool again.
took her back out and fired up no probs again as i pulled off in fist, after about 10 seconds she bogged down and died...that was it. nothing was gonna make her fire up again.
the next day, i took out the plug, drained the tank and put in another batch of fresh fuel. the plug was oily and wet. i give the plug a damn good clean. it wasn't perfect but it was near enough. i put the plug back in and fired her up. she started first kick. threw out some blue smoke and oil, but once i gave her a few good hard revs and put the choke in, she was kicking out the right kind of smoke and the oil wasn't coming out the silencer any more. i took her out the front again, in first, riding her around for 10 mins in the mid range of first but trying to be a little more aggressive on the throttle to keep it burning. turned her off for 10 mins, started her up again and after about five seconds she bogged down and died and once again, that was it. dead!
the plug was again oily and wet.
and thats as far as I have got!

sorry for the long post but i am getting pretty annoyed. it does say in the manual that the plug may foul during break in which i did expect but how long am i gonna have this problem for. every time i take the thing out am i gonna be putting a new plug in.
so, does anyone who has had an hour to read this have any idea what the problem is or what it could be???

any ideas please let me know.


P.S I am not particularly mechanically minded so go easy on me :) and i am on fuel mix of 32:1 which is what is reccomended in the manual. also, the weather is very very cold and damp and the bike has been set up by the shop who sold it me so it is bog standard.
hope someone can help.
cheers guys.

 

[kawakid]

the most likely problem is that the plug is fouling because you are not able to revv it really high during break in.(It looks all black and oily when it fouls). The oil coming out of your silencer is sometimes called "spooge" and that is normal, but if as much is coming out as you say then your carbeurator is probably jetted too richly, maybe go down a size on the main or pilot jet. But one more quick solution is to buy a hotter sparkplug, so that it wont foul at low rpm's. The spark plug should have a number on it, for example if it said 10 or so then maybe try a 8 or 9 plug untill you break the bike in and ride it hard. Remember to lean out the carbeurator too.

 

[kawakid]

After you try this, tell me if it works at all.

 

[OnAnySunday]

Im not very mechanically inclined either.
But in your post you say you left it idle for 5 minuites -w- the choke on??
A bit excessive i think.
Usually i will leave the choke on (and i only use it on cold/cooler days) for about 10/30 seconds before going mid-way then off.
The choke is just to get the motor running, switch it off as soon as possible.

There are probable carb. jetting issues as well.
Are you in a "high altitude" location?

 

[syko]

thanx for the tips guys.
i left it idling with the choke becuase it won't idle without it. it just dies.
So do i have to turn in the idling adjuster screw to remedy that?


also, when the bike is broken in, does leaving a bike to idle for a prolonged amount of time cause the plug to foul on a 125?


once again, thanx for your help.
as soon as i try these things out i'll let you know how i get on Kawakid!

 

[syko]

by the way.
the plug that is in my bike is a standard plug and the maunual does not reccomend going any hotter than the one with the bike.
the standard plug is an 'NGK R6918B-9'

 

[Nevada Sixx]

when you mixed your fuel, did you actually put it in a gas tank and shake it up and then pour it over in it? if not, do so...
maybe you can go up to 40 to 1 mix,, and check to make sure your air screw on carb isnt turned all the way in, they are usually about 1 to 2 turns.
ive heard that if a bike needs the choke over 30 seconds, that its running rich.

 

[syko]

i mix my oil and fuel together in a gas tank before i put it in my bike.

i'm always a little bit nervous of running the fuel/oil mix on the lean side in case i end up seizing the engine.

 

[biglou]

I'm not the most mechanically inclined either (with smokers especially), but hey, two-smokes foul plugs sometimes, bo biggie. If you're way off on jetting, then that needs to be addressed for sure. My kTm (which are notorious plug foulers) only fouled a couple plugs in the two years that I owned it.

Here is my two stroke start ritual: Fuel on. Choke on. Kick it through slowly once or twice to prime the carb. Kick it like you mean it. It should start. Next, choke off after 15 seconds or so. Blip the throttle to keep it running. I never ride off until I feel some heat in the radiators. At first I ride conservatively until the engine is fully warmed up. After that, let her rip!

A lot of the two-stroke mx bikes are set up to have no idle. I'm told this gives better snap off the bottom when accelerating.

A couple of guesses here as to why you fouled out-You left the choke on too long and loaded it up. Too much to burn off and the plug fouled. And, not reving it up let it load up and it fouled out when riding.

Personally, I've found that there's a lot for the "seat of the pants" feel of a two-stroke. You can just sort of feel how they're performing and responding to input. Lets you know when it's time to wick the throttle and clean her out.

btw-Great first post. That's the kind of detailed info to present when asking a question. :thumb:

 

[oldguy]

With a 2stroke remember it is probably jetted rich from the factory. Also leaving the choke on runs it on an even richer circuit. Put in a brand spanking new plug and just use the choke to get it running (only when cold). You may need to adjust the idle screw to keep it running with out the choke but keep in mind 2 strokes are not usually set to run on idle for extended times.
Once the bike is fired up let it warm up by gently blipping the throtle a few times to keep it running and once you feel warmth in the radiator start riding it. As long as you stay in first and second gear babying it you will keep fouling plugs and spooging. 2 strokes are made to rev and once you get on it you will aleaviate some of your problems
the pilot jet covers your fuel in the first 1/4 throttle
main jet and needle cover the fuel at higher revs.
do a search on jetting and pay attention to any posts by Rich Rohrich for great advice

 

[oldguy]

Lou beat me to it

 

[syko]

once again, cheers for the info.
I know that 2 strokes generally can be plug foulers but i've never expereinced it so soon with a brand new bike.
I guess i had just hoped that the shop i bought it from had set it up correctly.

 

[Nevada Sixx]

was this bike new off the floor? seems strange that it took 10 kicks to fire it up,,maybe a jet in the carb has come loose or a shop rag was left in the air box. you may accidently check the wiring on your kill switch to make sure nothing is grounding against the bars.

 

[darringer]

Once broken in, with the proper jetting, your bike should be able to idle for several minutes at a time with no ill effects. It just takes a little patience to work out the jetting.

 

[zookieman]

You are not supposed to run your bike with the choke on at all!!!!!!!!!! When it fires up turn the choke off! If you wish to keep it running, stand there and give it gas until it is warmed up. if it wont idle than read in your manual how to adjust it. By running your bike with the choke on you are forcefeeding it fuel (Thus it is running rich). At idle RPM's your engine is not getting hot enough to burn all those deposits away (DROOL!). Before you mess with the jetting change the plug and go rip on the bike! Yes bike generally come way to rich but you cannot know that until you ride the thing.

 

[marcv125]

What ratio are you running? 32:1 ? If your adding to much oil this could be some of your problem also.

When you start the bike for the first time, choke out, kick her until she start then let the choke back in (except in extremely cold temperature, because she would most likely die) and if you have to give it a little gas, and never run the bike with the choke on. It really wont hurt anyhting if you do it for a short time, but it will foul a plug very quickly. Just let her idle for a while until it becomes steady then ur set.

again what ratio are you running and i assume stock jetting right?

 

[gixer]

on my 03 I have droped her down one jet size in the main and pilot. I have run hotter plugs also. They come jetted to hight from the factory. I had some one who races kx 250's and they could not belive the bike after I droped down the jets. She will run even faster and harder. Keep the recomeneded plug.
Now if I can get her jetted for the trails in the woods of Paragon I will be happy.

 

[KX02]

Here's a couple of notes from when I got my 02 KX125. Yes it is probably not set up to idle, that is easy to adjust if you look in your manual. I had to turn my idle up. It is probably jetted rich, my bike had one size larger main jet than what the manual said was the "stock" size. A hotter plug should help too. Leaving the bike idle with the choke on is not a good idea, it will cause fouled plugs, so adjust your normal idle up and shut off the choke soon after you get it started. Lastly I know some people do not like this idea, but switching to more like 40:1 will clean up the exhaust mess. As long as you use a good oil, you should be fine at 40:1. Once you get past this initial nightmare, you'll be having fun, so hang in there!

 

[darringer]

I disagree with the 40:1 change. Spooge out if the silencer is a jetting issue, not a premix ratio problem. Going from 32:1 to 40:1 will make your bike run richer, making the problem worse.(more gas/less oil by volume).

 

[mdkuder]

Oil are you supposed to put oil in the gas?

 

[ironworker]

Fuel & Oil

Do you have one of those Mixing Cups that look like a Tall Measuring cup? if so there are 3 different 32:1 ratio's on that cup, one for 1 gallon and 1.5 gal 2 gal and 2.5 gal, make sure you are mixing the right 32:1 per the gallons of gas you are using, a brand new bike should be jetted correctly from the dealer, and if bought in high altitude i would think it would be jetted from the dealer for high altitude settings.

 

[ML536]

Whether or not the bike is jetted to richly, I think that the reason you are having the problems is that you let the bike idle for five minutes with the choke on, like Big Lou and Old Guy said. Two stroke race bikes like your KX are not set up to idle (although you can adjust the bike to do so), and are not meant to have the choke on that long. Maybe 15 seconds like noted above.

I suspect that your bike is "loaded up" with fuel and oil in the lower end from the five minute idling and easy riding around in first gear. Because the choke is making the fuel mixture "richer" (increased amount of fuel/oil relative to the amount of air being pulled into the engine) leaving the choke on that long made the loading up problem worse. Same thing with extending idling. At low RPM's, like idling, there is not a sufficient volume of air moving through the engine, so some of the fuel/oil mixture is condensing on the sides of the lower end and pooling down there. Even when a bike is jetted properly, this happens to a (minimal) extent. The bike will smoke a little more and not run cleanly until the bike is "cleaned out". In other words, before the bike runs well after starting the engine, the excess fuel and oil in the lower end must be cleaned out. It sounds to me like this is your problem, whether or not it was contributed to by improper jetting. Here is how to clean the bike out:

Warm up the bike using the method Big Lou described. When you turn off the choke, you will have to "blip" the throttle occasionally to keep the bike from stalling. When the bike is warm, start riding it. Get it up into second gear and slowly open the throttle all the way. Your bike will probably be blowing a lot of smoke and oil out the exhaust, but don't worry about it, this is just the excess oil and fuel from the bottom end. Do this a few times and the bike should be "cleaned out" of the excess fuel/oil in the bottom end. At that point, it will probably smoke a bit when you twist the throttle, but nothing too heavy.

At that point, your bike will be cleaned out. That should cure your problem. If it still smokes excessively and runs poorly after you cleaned it out, then you may have to adjust the jetting in the carb. But don't cross that bridge until you have to.

 

[zookieman]

FIRE THAT BIKE UP AND GO RRRRRRRRRRIIIIIIIIIIIPPPPPPPPPPP! ON IT. THAT THING IS A RACE MACHINE NOT A MOPED FOR DELIVERING NEWSPAPERS. This, as previously stated should clear your problem.

 

[skillzman1]

I also agree with 'old guy' about the plug--toss it in your tool box and buy a new one to start fresh with.I've never had much luck with cleaning and re-using a fouled plug on a 2 stroke.Once it's fouled /cleaned it still never had the punch a new one had.I learned that on my kx 250-it was my first mxer and I never really wound it out too much,because I was trying to get a handle on it!After a full summer of riding it I thought I was getting it down-then I put a fresh plug in it -just because I figured 'why not' and man that thing was a whole 'nother beast-4th gear wheelies- no clutch!

My point to this being that the old plug still started and ran ok -but was obviously not as fresh as a new plug.
As far as the jetting goes-the elevation you live at will dictate what it should be jetted at.If you bought it new locally-a good dealership 'should' have the jetting set properly,if the problem persists it would be worth having a 'good' dirt bike mechanic look into it however.
My buddy bought a '98 cr 125 and always complained about it being 'wimpy'-he took it to the local dealership and they threw $$ at it for him and it still came back with the same complaint.He brought it to me ,I tore it apart and referenced the jetting,needle size/position,etc,.. and found it to be jetted for 7500 ft. above sea level!We live at 350 ft!!So occasionally even the dealership gets it wrong.

But in your case ,it's likely to be similar to my rm125--during the winter it doesnt get ridden-but I start it up on warmer days...mostly because I'm 'jonesing' to ride.It doesnt get out and run thru the gears like it needs...so it drools all over the swingarm..until I get to the track and rip on it for a few minutes!!

I personally dont worry too much about manufacturer's recommended break in routines...I'm not suggesting you go crazy with it right outa the box..but after letting it 'warm up' a few times ..as you said..it should be ready to crank it up a little..IMO!

 

[Chili]

I also agree with 'old guy' about the plug--toss it in your tool box and buy a new one

Can't wait to see the post when he get's back from the shop and finds out how much that plug costs :ohmy: