2005 Honda Cr125 Fooling Spark Plugs

[mxrider19868]

Just bought a leftover '05 Honda Cr125 from a dealer completley stock. The bike is fooling spark plugs like crazy. I am currently running a 50:1 w/ golden spectro and 91 octane. Airfilter is clean. What should I do? How can I fix this so I can get my bike running good?

 

[DirtDawger]

I do not have specific knowledge about your model but if you are fouling spark plugs jetting is the first thing that comes to mind. Sometimes the manufacture will set a bike up rich for CYA purposes. Especially competition bikes. Search the many threads on jetting and I think you will find your answer.

 

[BSWIFT]

Read the "jetting" thread at the top of this forum. If you have a manual, check what size the stock jets are and go 1 size smaller. Start by finding where your air screw is set. 1 1/2 turns out is good starting point. Change the pilot first and with a new plug go thru the proceedure in the jetting thread. Get one circuit good before doing the next. Make one change at a time or you will get messed up. Jetting is mundane and time consuming but not that hard. Patience will get your bike jetted and running strong. Try your premix at 40:1 or 32:1, this will lean the fuel/air ratio slightly and it will richen the oil/fuel ratio

 

[tcarn09]

Does it run great for 15 to 20 minutes then it just bawgs out? Also when you put a new spark plug in does it run good then foul 15 to 20 minutes later? My 97 cr 125 does this and i have had the jets replaced and the float. It still is the same. Im starting to think its a electrical problem for mine, but im not sure.

 

[briguy125]

When I first got my 2005 cr125 my did the same thing. I changed the jets to a 410 main raised the needle clip 1 spot turned the air screw 2.5 turns out and i run a br8es spark plug. Now I only go trough maybe 4 plugs a year.

 

[kx125412]

I would be pretty mad if my bike fooled plugs. But yeah do what the other guys said it's just a little turn here, another turn here, until the bike runs good.

 

[newfie125]

hey i had the same problem with my 2005 125 and you have to put a 45 jet and a smaller needle valve and that will solve your problems

 

[BSWIFT]

Jetting can seem very intimidating and what works for one rider is not necessarily going to fix your problem. Jetting has quite a few variables so read the thread and articles on jetting, buy several sizes of pilot and main jets, several new plugs, and a note book. When jetting pay close attention to temperature and humidity as well as the elevation you are at. When you get it close you will know. Just be patient it is worth the time and you will understand it better in the end.

 

[ellandoh]

if i was you i would change my oil mix to 40;1 at the very least . then turn your air screw out till it idles best and drop the needle 1 position. trust me on this and try it. if you still have problems search for spankys jetting guide, try that . your problems will be solved, if not get back to us. :cool:

 

[hks308]

deff. change your mixture to around 38:1 and make sure your bike doesn't run out of gas, that could do it to.

 

[xcracer72]

50:1 holy sh!t!!!!!