my bikes driving me mad - fouling plugs!

[hairybrain]

Hello,

Any advice would be greatly appreciated. I own a 1997 Kawasaki KX125 and recently I have been having problems. Basically, everytime I manage to start it up - it runs reasonably well until the engine bogs and it cuts out. This happens usually after five mins or so and I cannot start the bike again no matter how hard I try. When I take the plug out it is black with oil, although if I replace it with a new plug it starts fine. It does this after every single ride and I am at my wits end. I made the mistake of putting far too much premix into the engine when I first got the bike (Silkolene Comp2) although even though I have emptied the tank and replaced with the correct mixture it keeps on doing this. Is the fuel mixture too rich? I run it at 32:1

Thanks

RC

 

[cr2504life]

It sounds like you need to jet your bike. You should be able to find loads of info about in on here. There is also good infor on eric gorrs site. Good luck.

 

[Shig]

Definitely sounds like a jetting problem to me. Assuming you have the correct main jet in the bike (call your local shop to check what most people run in your area), it's probably all in the needle clip adjustment. If you move the clip on the needle up one slot to the next leaner position it should solve all of your problems.

 

[MXTex]

Is this a new problem? Did it run well before then suddenly start fouling plugs? Please advise and we'll be able to give you a more definitive answer. It could be jetting. But if this jetting worked well before then I would potentially look elsewhere.

 

[CaptainObvious]

Hmmm, sounds like it could be many things to me. If you can isolate the problem to a specific throttle position (therefore a specific carb circuit), the problem is more than likely the jetting. While jetting could be the problem, if the problem happens regardless of throttle position check these items…

Poor compression (rings or piston & rings)
Misadjusted float height or poorly assembled float valve
Clogged carb vents
Dirty air filter
Weak CDI
Old/bad gas

 

[hairybrain]

Thanks for the info. I've recently changed the filter and oil, and everything else on the bike is fine. It was running fine until I put too much premix in that time now it wont even bump start unless I change the plug every ride (which I cannot afford to do). I have not checked the carb yet, so this is what may be wrong. I am new to motocross and have very little mechanical knowledge so any further info would be greatly appreciated. I have no idea how to fix jetting, should I take it to my dealer? Although I would love to learn how to fix it myself.

Thanks guys

 

[hairybrain]

re: fouling plugs

Is this a new problem? Did it run well before then suddenly start fouling plugs? Please advise and we'll be able to give you a more definitive answer. It could be jetting. But if this jetting worked well before then I would potentially look elsewhere.

Thanks for the info. I've recently changed the filter and oil, and everything else on the bike is fine. It was running fine until I put too much premix in that time now it wont even bump start unless I change the plug every ride (which I cannot afford to do). I have not checked the carb yet, so this is what may be wrong. I am new to motocross and have very little mechanical knowledge so any further info would be greatly appreciated. I have no idea how to fix jetting, should I take it to my dealer? Although I would love to learn how to fix it myself.

Thanks guys

 

[skagracer]

you have a jetting problem but how long have you had this bike what oil and filter did you change on a kx 125 because there is no filter unless some one put in a inline fuel filter ? the only oil you can change is the clutch and that has nothing to do with this problem what plug are you useing? go to the dealer call if you don,t what to drive and find out the facts on your bike - jeting witch means pilot, needle and what clip of the needle 3rd mostly from factory and main jet , plug type, put your bike to stock and start from there oil mix is 32/1 but if your are use any good brand of oil 40 to 50/1 is what you run with all the facts we the rides in the know can help you good luck freind

 

[High Lord Gomer]

Do you turn your gas off when you stop riding / at the end of the day?

It could be a number of different things, but I had a CR with a float problem that, when left sitting, would fill up the carb and crank with fuel. It would start and then run for a few seconds (usually not longer than 10-15 seconds) before fouling the plug. Merely turning off the gas when I stopped avoided the symptom of fouling plugs, even though it didn't correct the problem of a leaking float valve.

 

[will-NOOB]

fouling plugs

dude i had the very same problem i once sliped to much oil in my yz125 and every time i wanted to ride it afterwards it would run and then bog down and cut out what i did was chuck old fuel away obviously got the carb cleaned new plug then it ran fine but what u need to do if your bike wont start is it probably wnt like last weeks petrol much especially the stuff thats in the carb so keeping the fuel off tip the bike on its side let the fuel drain out of the carb then kick it over ten or so times with fuel off remember it will burn off all the old fuel and draw some air into the carb then switch fuel on give it a few pumps on the accelerator while kicking it over and hopefully it should start nicely

 

[reelrazor]

Don't overlook the possibility that the clutch side crank seal may be bad.

Does your transmission oil level stay right? If not, does it leak onto the ground?

 

[souphmars]

if it was the crank seal-u would be able to tell a difference in the way it would run all through the throttle-i would say clean the carb real good-check the float-then go through the jetting-if u have done any kind of mods to it like a pipe or something, it would cause it to be out of whack

 

[syn_01]

Hello,

Any advice would be greatly appreciated. I own a 1997 Kawasaki KX125 and recently I have been having problems. Basically, everytime I manage to start it up - it runs reasonably well until the engine bogs and it cuts out. This happens usually after five mins or so and I cannot start the bike again no matter how hard I try. When I take the plug out it is black with oil, although if I replace it with a new plug it starts fine. It does this after every single ride and I am at my wits end. I made the mistake of putting far too much premix into the engine when I first got the bike (Silkolene Comp2) although even though I have emptied the tank and replaced with the correct mixture it keeps on doing this. Is the fuel mixture too rich? I run it at 32:1

Thanks

RC

Sounds kinda like what happned to me today, except when i replaced the plug it still wont start, so yeah i suspect jets are the culpret, try spraying some carb cleaner on em, make sure your float bowl is clean as well.

 

[sunnyboy]

first thing you need to get is a service manual for your bike-it will show you step by step how to work on your bike--you may have always had a rich condition but then you put in to much oil in your gas,oil normally collects in the crankcase but now you have to much oil collected in thier and combined with a mild rich condition you are fouling plugs---get fresh gas and a 50:1 oil and add the fresh mix in your tank,lower the needle in your carb.one notch by carfully raising the clip one notch,install a new plug now you need to start and ride the bike it should start running better after a while as you burn off the extra oil you have in the crank case.if this has no effect chances are you have a bad right crank seal and are sucking trans oil in to the motor or you have a blown head gasket and it is sucking in coolant.look to see if coolant is fouled and our it uses coolant--the same for the trans.oil