RM-125 Keeps fouling plugs

[skittles]

after a good hour run it will foul the plug... WIl have a layer of oil on the plug which i guess is just drowning out the plug and not allowing it to fire??? - if i take a aluminum brush and get it all off, put the same plug back in, it will fire again.


what is causing this? im running 32:1 fuel/oil ratio(although, at the moment with cheap quaker-state oil) :coocoo: - should i change to 40:1, or will this not help at all?

 

[2 strokes for life]

lean out the jetting.

 

[Denny1068]

40:1 helped for me greatly and the type of oil you use will effect it...try a cleaner burning oil at 40:1 if that fails then re jett it

 

[Denny1068]

just a tip...you shouldnt be running quaker state through it lol, even if its a 2t oil ive tried about everything at the dealer and yamalube is what i use to use fouling plugs all the time, amsoil you pay for the name, the best ive found is 927 castor oil by Maxima buy that

 

[elcamino12sec]

try a b8es plug instead of a b9es which is probably in it now, also 40:1 with quality red line or mobile 1 mx2t oil should help out quite a bit

 

[2strks4evr]

b4 i bought this 03cr250 i tried all the oils,then switched to amsoil.mix 50:1 and still have the original plug in it!although its not the best practice for a race bike.but runs and starts like a honda.hey is there a mopar pulling that 12 sec. elcamino? :laugh:

 

[jrmobb]

I have a 02 rm125 still have the original plug for years now i think prob jetting. you can use the 50:1 synthetic oil to help but id say jetting.

 

[whenfoxforks-ruled]

try a b8es plug instead of a b9es which is probably in it now, also 40:1 with quality red line or mobile 1 mx2t oil should help out quite a bit

YES,run this plug and watch your electrics,wonder where your top end power went??????????? Jet your bike after you rule out mechanical issues and make sure you at least run a resistor plug!!!!JEEZZZ COME ON!

 

[HubertGarfunkleIII]

something with your carb

 

[nikki]

I'm with elcamino - what plug are you running? If you're running a BR9ES, try a hotter BR8ES plug.

 

[madeincanada123]

change jets...and ride like a man

 

[kawicam250]

I'm with elcamino - what plug are you running? If you're running a BR9ES, try a hotter BR8ES plug.

question: i started out running my bike with a BR8EG(S) and then i switched to a BR9EG(S), while messing with the jetting and going to 40:1 instead of 32:1. i know that there is a power difference between the 2 plugs( the 8 and 9), but how significant is it?


BOT: try running 40:1 and using Maxima SuperM oil. i used to run Yamalube before Maxima, and i could definetly tell a difference. my bike sounded cleaner and clearer and i had far less "spooge" coming out of my silencer :cool: .

 

[whenfoxforks-ruled]

Kcam,good choice,Nikki-he did not have the r in it,I got upset,,,,,,,RULE OUT MECHANICAL ISSUES,THEN JET THE BIKE! sorry,my key stuck,random act of computer violence! But,serious,maybe jetting sounds like voodoo,once done its like everything else! No big deal,what was I thinking! It is the blood flowing into your bike,yes it is a big deal! The way you ride a old race bike should have nothing to do with it,jetted right and allow for temperature and extreme changes in feet above sea level is the only variables you have. Mechanical problems and the guy's come out of the woodwork!

 

[snb73]

40:1 is richer (more fuel, less oil) than 32:1 Either ratio will work for your bike. (32:1 is more common for 125's)

Don't chase a jetting problem with hotter plugs and changing fuel ratio's.

Pick your ratio and stick with it, mix fresh premium fuel with a high quality MX bike premix oil. ie; mobile MX2T, yamalube, golden spectro, Maxima, ect...

Instal the factory recommended RESISTOR plug.

Set your jetting to factory specs, then rejet.

Here are a few links for reading:

http://www.keihin-us.com/tune.htm

http://www.ngksparkplugs.com/techin...1000&country=US

http://justkdx.dirtrider.net/carbtuning.html

http://www.powroll.com/tech_specs_jetting101.htm

http://www.duncanracing.com/techfaq...n-jetting.phtml

http://www.keihin-us.com/am/tuning/

http://www.dansmc.com/spark_plugs/s...gs_catalog.html

http://www.ngksparkplugs.com/techin...1000&country=US

http://dirtrider.net/forums3/showthread.php?t=42618

Good luck, Steve.

 

[kawicam250]

i know what youre saying snb73, but the reason that 32:1 is more common is 125's is because most 125's are track ridden only, they never see trails. 32:1 is more of a track, higher-speed ratio, where as 40:1 is a safer( less chance of fouling because of less oil) and is better for trail, slower-speed riding. BTW: you posted a nice set of links :cool: .

 

[rmc_olderthandirt]

im running 32:1 fuel/oil ratio(although, at the moment with cheap quaker-state oil) :coocoo: - should i change to 40:1, or will this not help at all?

You should be able to get your plug to last at just about any oil mix. It is NOT a good idea to keep changing the mix you are running and you really shouldn't change brands or type of oil. If you want consistant results, pick an oil and a mix ratio, adjust your carburetor to match and then stick with it.

As others have said running a hotter plug could solve all your problems. What plug are you running now? The plug will most likely be identified with some letters and a number. The number indicates the "heat range", where a lower number usually indicates a hotter plug. If the plug is running too cold it won't burn off the oil deposits.

It is also possible that you are simply not riding it hard enough. It is common for a two stroke to "load up" when ridden gently for an extended period. If the engine never gets up to its intended operating temperature it won't burn off all the oil deposites. This is even more true of the exhaust. A good hard run can really clean things out. After about an hour of putting in third gear with my wife and my bike will hardly run. A couple of minutes of trying to keep up with my son and bike is running crisp again!

Rod

 

[Tek307]

Check your jetting