125-200cc carb question

no time to search so just posting away. I sacked up & took the mikuni off my 125. sussed the pilot & main no dramas but have 2 questions-whats the tiny little jet in behind the pilot in the brass tube(tiny little thing)? I have a spare '50' of this jet but no idea what it does. do I need to change it/does it improve or affect the fueling circuits? & how the hell do I get the slide off the needle/cable to see where its at clip wise? thanks in advance yall

if you pull the spring right back - use long nosed pliars - you can push down on the cable and the nipple will come out . then use a 6mm socket to undo bolt that sits above needle clip
use pliars to push spring right back up when re aseembling . it gets easy with practice.
make sure you get the slot inside of the plastic piece at the end of the spring in the slot on the bolt..
not sure on other question but if you ve sussed which the pilot and main jets are thats all you should need to play with on jets
The main jets are small - in the middle - pilots long ..
50 sound s like a big pilot jet

yeh got the slide off, spoke to AUSKY! just PMd you mate. the other tiny little jet isn't pilot or main, its like 5mm long or so & sits in the brass tube next to pilot & main. ???

Starter jet....works to richen up the choke circuit - hard to start cold with choke up, then you may have a lean starter jet.

Personally, wouldn't worry about it until you get the other circuits flowing right.

As above, thats the starter jet. Mine didn't seem to want to budge so left it in there. Think its 80 and theres a 50 in the spares kit.
Bike should start fine once you have the correct pilot jet in it.

was thinking it was the starter jet as I saw mention of one in the manual, guessed it would be around 80(got the 50 in spares) but same deal watky-wont budge & I don't wanna bust anything so leaving it alone for now. bike starts ok, just doughy down low-bogs a bit. never ridden a 125 before but know it should be crisper than it is. PFG warranty jetting I guess! left the 460 main in there, swapped the 45 pilot for a 40 & left needle & clip alone. will try this & see what happens then play with clip heights as its easier to get too, well sort of.

PFG won't warranty jetting if you lean it out and seize it though .
Get the following RM needles and test with the optional 5 slide from the spares kit
6CHY 16-62 (clip 3 or clip 4)
6CHY 17-61 (clip 3 which will = clip 3.5 on 16-62 )
That way you can drop the pilot down to the correct size & the RM needle gets rid of the midrange lean spot of the stock needle.
With either of those needles start with a 35 pilot for safety and go down as needed. Probably be happy with a 30 pilot.

yeh I wanna err on the side of caution so not getting too drastic with it. figured it was about time I learnt this jetting caper though. im gonna get a lectron when money permits so just a short term thing. don't wanna be buying needles really unless it makes that big of a difference? just make do(best possible jetting) with what I got. is the stock needle better if its leaned out a clip or 2? I have 2 needles, one that has a gradual taper the whole way & another that has a small straight section at the end then a small sharp tapered section then tapers out gradually-forget the numbers sorry. came with the gradual tapered one in the carb so left it in there for now on clip 3. whats everyone running for mains?

Someone else will have to chime in regards the best jetting with that stock needle. Yes leave that stock needle in and don't use that other weird stock needle.
Can't remember 100% but PFG recommends either 35 or 37.5 pilot stock needle clip 3 or clip 4 and a 460 main.

try riding along a road at 1/4 throttle and see how the plug reads
it could be fouling plugs - then it will be sluggish

the #5 slide(#4 in there atm) im told helps it breathe easier-more cutaway section. another thing to try I guess?

You need to determine the reason behind the sluggishness first.
It could be any of the following
* Rich pilot, then lean needle (as is usually the case with the stock needle)
* Overly rich jetting
* PV set up issue (fairly common)
* WR Ignition & flywheel weight
Do as Lapper suggested and do plug chops to determine if it's rich, lean or what ever especially before changing the slide.
#4 slide is the normal slide to use with the stock needle, going to the #5 will lean it our even more. Not sure of anyone on here using the #5 slide with the stock needle.
Mine still has a slight flat spot if your not in the right gear but seems this is now due to the WR ignition & flywheel weight and can't be jetted out.
I try'd stock needle #2 and the bike didn't like it at all was a dog to ride, also the Dyno A/F result showed big lean spike as the PV opened, #3 was a little better but still had a lean spike on # 4 & #5. It is that lean spike that the RM needle gets rid of.
There is a tare road hill that I go up to get to the tracks I ride on, with the stock needle the bike wouldn't pull up it in 6th gear just bog down through the mid range. With the RM needle I can stay in 6th gear, back off the accelerator & accelerate again staying in 6th

Which RM Needle exactly are we talking about here? Sounds interesting but if I went to a Suzuki dealer and asked for an RM needle I don't think I would get anything beyond ridicule.

Hi Shawbagga,

Get the pilot right first, in the XC 150 we went down to a 32.5, however the 165 went down to a 15 and still seems fine (have adjusted air screw and still fine). I have the standard needle (2nd clip from top) with a 5.0 slide in the XC 150 currently and about to change it to the RM needle, this was much better on the 165 and by all accounts on this site is the way to go. Check out the jetting database on this site, plenty of information. Check out posts by "lankydoug" going back two years or so, he seemed to have the TMXX "down pat". They appear to prefer constant altitude, so potentially here they are ok as we don't have the great range in altitude the US does.

RM 125 Year 2004. 6CHY 16-62 Needle is what most start with, get the half clip washer and holder as well so you can do half clip movements if needed.
1/2 clip washer P/N #13394-36F20
Holder P/N #13518-36F20

stupid question, what is your temperature and altitude
these are what you need to jet around

Ummm, 2premo are you asking me? If so, I at near sea level give or take five meters and hovering around thirty two degrees Celsius year round, the big difference is in the humidity, we vary from around 35% in the dry to more than 80% relative humidity in the wet season, good fun if you like growing fungus in your nylons.

I am in similar conditions and I did gave up on chasing the jetting on the carb
get a lectron and your fine

your not thinking anymore on getting the jetting better you just enjoy it

Robert-Jan

Interesting, so for a 2013 WR125, which lectron do I need? the 38mm? are there any more mods or does it just slip in?

I have a 36 mm and it was just a plug and play affair
I might lean the rod a out for a fraction but performance wise I could not get bothered with it

Its respond is amazing

Robert-Jan