Spark plug

Hi guys, which spark plug works better on woods, I use a lot of slow/mid range and the BR9EG dies all the time.

I've been told that the BR8ES will work ok but want to hear from you before buy it.

Cheers

what bike do you have? plug makes me think its a 125.

 

its probably not the plugs fault, its your jetting. post up your bike, current jetting, temps and elevation

Edited by mynewcr250

what bike do you have? plug makes me think its a 125.

its probably not the plugs fault, its your jetting. post up your bike, current jetting, temps and elevation

You are right, it's a Honda CR125 06 ...

London/UK/Sea Level - Cold weather (avg 5/10 celsius winter time and 15/20 in summer time)

Bike with FMF fatty/the "Q" silencer

Boyesen reed

0.5cm spacer beetween cylinder and pipe

Keihin 38 airstriker with TPS (not connected) - not sure but should come from a KX

170 main

#6 slide

N2ZH needle

needle pos = 3

air screw = 1/2

pilot = 38

Thanks a lot for your help, really appreciate it....

have you tried turning the idle up higher?

where di you get your jetting from? seems odd for a 170 main and a 38 pilot.

 

 

170 main
#6 slide
N2ZH needle
needle pos = 3
air screw = 1/2
pilot = 38

have you tried turning the idle up higher?

where di you get your jetting from? seems odd for a 170 main and a 38 pilot.

A guy gave to me ... He tuned a lot of bike but you not the one saying that... Whats your clue ontdhsi?

What year KX did it come from? i would rejet it to as close to that year as possible. 

This is from PC jetting on  a 2000 KX125

 

http://www.procircuit.com/jettingspecs4.htm

KX125 160 45 N7PW 3RD 1 1/2 55 6

Unfort dunno and I dont have any way to discover it :-(

Well then you need to try new jetting. 1/2 out on air screw says pilot is wrong. I would get some extra jets 

I don't mean to insult you, but I do have to ask if you plugged the power jet on that carb? I am not familiar with that needle, but I would think a 125 would be running a considerably larger pilot than that. Have you checked your reeds lately? Worn reeds or a worn top end will mimic rich jetting which could be why you had to go to a 38 to compensate. It's been awhile since I messed with a 125, but those jets just don't sound right to me. I run a 175 main and 45-48 pilot in my 250 and my jetting theoretically should be leaner than yours depending on your needle. The right side crank seal will also pull in trans oil and make your plug read rich. Is the bike pinging at all, making a hard chug chug chug sound when it comes back down to idle, or have a high idle? I guess what we are getting at is you shouldn't be fouling plugs with your jetting as lean as it is.

Edited by Curt026

Mynewcr250 ... Whats your clue? Thanks

Stop asking for clues and go buy some jets.

I don't mean to insult you, but I do have to ask if you plugged the power jet on that carb? I am not familiar with that needle, but I would think a 125 would be running a considerably larger pilot than that. Have you checked your reeds lately? Worn reeds or a worn top end will mimic rich jetting which could be why you had to go to a 38 to compensate. It's been awhile since I messed with a 125, but those jets just don't sound right to me. I run a 175 main and 45-48 pilot in my 250 and my jetting theoretically should be leaner than yours depending on your needle. The right side crank seal will also pull in trans oil and make your plug read rich. Is the bike pinging at all, making a hard chug chug chug sound when it comes back down to idle, or have a high idle? I guess what we are getting at is you shouldn't be fouling plugs with your jetting as lean as it is.

 

Hi, no ... power jet is disconnected. this bike doesn't support it, I blocked. Reeds are new, top end dunno unfortunately :-(

Stop asking for clues and go buy some jets.

 

LOL

 

40 or 42? shoot please!!!

 I would buy extras...40 through 45 pilots.... and then a 160 through 168 main.

Mynewcr250 ... Whats your clue? Thanks

i was hoping you'd have the stock stuff installed. it would make it easier for others to offer advice based on your current jetting/temps/elevation and what not.

 

honestly, the problem for me is, im reading honda used needles that dont seem to have any information online on the tapers (wondering how that needle compares to stock). the format that they use to describe the stock needles is done with 4 numbers (20-68, 21-70) which makes it pretty hard for me to find any info on line. i think the previous owner may have went to that needle not just for tuning sake, but also for the fact that you can at least find some info on line on its tapers and what not.

 

i wouldnt worry about the pilot or main right now. that needle maybe have a really rich 1st taper compared to stock or a really rich straight diameter vs stock so the leaner pilot may just be needed to get the feel the previous owner wanted. your slide could be playing a roll here too. does this bike come stock with a keihin? if so, what is the stock slide?

 

in the trails and woods you are on the needle. the pilot and main are small parts of the puzzle, concentrate on the needle. if youve got a really rich needle taper that coincides with the throttle position that your bike sees most you will foul plugs.

 

if it were me, the first thing i would do is lean my needle out 1 clip.

Edited by mynewcr250

 

 

Keihin 38 airstriker with TPS (not connected) - not sure but should come from a KX

It is not a Honda TMX carb...Its a franken-carb at this point...That is why i would start with pro-Circuits jetting specs.

 

 

http://www.procircui...ttingspecs4.htm

KX125 160 45 N7PW 3RD 1 1/2 55 6 

 

 
  •  

The problem with the pro circuit jetting is that's for a bike running the power jet circuit and a totally different engine (cylinder reed). I agree with leaning out the needle, which would be to put the clip one notch higher. Make one change at a time. That needle must be really rich as mynewcr has pointed out. If nothing seems to work then maybe try a different needle all together. I believe the DDK is a popular choice for 125's. Needles are like 6-7 dollars and can be found at jetsrus.com or another site from wherever you live at. I do completely agree with mynewcr again that we need to try and find out the exact dimensions of that needle you are running. I am not a "needle wizard" but surely there are specs on it somewhere in the great wide web. It would also be really helpful if you knew what manufacturer makes that particular needle. Suzuki, Kawi, Yamaha, ktm?

Edited by Curt026

looks like it may be from a RM 250..being a 38mm it probably is from a 250. 

 also shows being used in some KTMs

 

here is a thread showing some info on the N2ZH.....looks to be 1 needle richer than stock for the RM250

 

http://www.thumpertalk.com/topic/844918-2-stroke-needle-question-and-premix-question/

 

If it were me....I would still use the 01 KX125 as a baseline.

KX125 160 45 N7PW 3RD 1 1/2 55 6 

Edited by Blackwoodz

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