sdg pro 125 jetting????????????? need help

Mini Dirt Bikes & Pit Bikes Forum

Help Support Mini Dirt Bikes & Pit Bikes Forum:

MINIMOTA

Member
Joined
Feb 1, 2012
Messages
20
Reaction score
0
ok bought the bike dont know much about it.. im verry mechanically inclined been riding all my life and workin on quads cars bikes all of it .. butt with this im new .. its a sdg pro mini 125 has stock exhaust and starts 1st kicks purrs runs good but when u hit the gas it stumbles butt when i ride it it seems a lil better butt also feels as thou its not enough spark and higher up like it gets its full spark again .. im stumped .. just wondering if any one has knowledge about this thing what size jetts come in it stock ,.. i have a 107 main in there now ... its a mikuni carb i think 26mm any advice or knowledge would help .. and what kind of plug should be in the thing and what oil .. right now i changed it im gona run honda motorcycle oil 10w40 i can trust honda .. where i can get parts anything .. greatly apreciated sorry if i dont help much .. butt im in need of help haha .. thanks ahead ..
 

sean01

Legend Spanner Spinner
Joined
May 27, 2007
Messages
5,934
Reaction score
120
Location
burpengary, brisbane
sounds like you need to adjust the needle height on the slide and maybe go down to a 102 main jet..

check your valve clearances.. .003thou on inlet and .004thou on exhaust..

with the oil just make sure you use 100% mineral oil as the clutches in these engines cant handle anything else..

NGK Spark Plug - C7HSA or a CR7HIX NGK IRIDIUM IX Spark Plug

have a look at our sponsors on the site as they will have a wide range of compatible parts for your bike.
guessing your in the states so Terry from Firepowerminis will be best to start with.. FirePower Minis
 

MINIMOTA

Member
Joined
Feb 1, 2012
Messages
20
Reaction score
0
sdg

hey sean thanks for the input .. and yes the oil is wetclutch approved as for there honda 4 stroke bikes with wet clutches .. so im sure i should be good .. also i dont think the jettings gotta come down i was just outside messing around and with the choke up it runs clean an smooth so im assuming i need to jet up and it has a 20 pilot and the guy at the moto shop said rule of thumb on the 4 stroke and mini motors if it dies or sputters from giving it gas at idle then my pilot is garenteed to be to small .. butt thanks for the link u put in there .. im just tryin to soak up as much info as i can about this bike..
 

tim_

Well-Known Member
Joined
Mar 7, 2011
Messages
746
Reaction score
10
Location
redbank plain, ipswich
i agree with sean

also depending on the age of the bike. but wouldnt hurt to get a new coil and cdi... only other thing i can think of would be its starving for something.. when you say hit it do you mean open it up fast and it sputters?
 

sean01

Legend Spanner Spinner
Joined
May 27, 2007
Messages
5,934
Reaction score
120
Location
burpengary, brisbane
just cause an oil is designed for wet clutches doesnt mean its correct for your engine...
if it is semi/full synthetic it is wrong and it will kill your clutch.. these engines use cork based clutches..

if your engine runs better with the choke up then you have some bigger gremlins to find...
maybe an air leak or even a bad carby, or maybe the tune is just way out..

by the way the dude from the bike shop that told you that about pilot jets is wrong..
the pilot jet controls idle mixture, the needle controls from about 1/8 throttle to 3/4..
so if your mixture screw is controlling the mix the way it should (about 1 1/2 turns out from shut) then you need move the needle height to control the transition from the pilot...
 

MINIMOTA

Member
Joined
Feb 1, 2012
Messages
20
Reaction score
0
ok i played with the needle i dropped it one notch to the 4th position got a lil cleaner then i dropped it to the last needle clip 5th position and runs great .. butt my thing is just because it seems great doesnt mean it is . i was hoping somone would know about these things and know the factory jetting sizes so i know where to begin with it .. idk if its even at stock jetting specs .. butt runs great right now .. and i ment that not full throttle from idle just a lil twist of the throttle even when it was warm it would sputter butt thats cleared up now .. with the needle moved and the fuel screw is 2 and half turns out .. seems good .. just wana know if anyone knows stock carb size jets anything .. more info better i know i may be a pest butt helps appreciated .. thanks again to the help and replys .. ALSO SEAN THANKS FOR THE OIL INFO .. ITS NON SYNTHETIC JUST PLAIN 10 40 HONDA OIL NOT SEMI OR FULL I NEVER USE THOSE IN ANYBIKES .. SYNTHETICS ARE DESINGED TO REDUCE FRICTION .. AND I NEED SOME FOR THE CLUTCH .. THANKS THOU
 

Kurlon

Active Member
Joined
Feb 6, 2010
Messages
43
Reaction score
2
Location
North Eastern US
Carb is a 22mm Mikuni, but I'll be damned if I can recall OEM jetting any more, been too long.
 

MINIMOTA

Member
Joined
Feb 1, 2012
Messages
20
Reaction score
0
thanks for that info bro .. ^^ butt i think i found out some more info and kinda bummed cuzz this may make my headache a lil worse so appong good inspection and some research ive come to conclusion the bikes actually a 2005 speed mini 107 butt i have the 125 pro mini motor .. had sdg run the vins .. and now im in another world .. the kid i got it from says its all stock no one swapped the motor so maybe somone before him had swapped it seeing the old 107 motors are junk .. butt did they swapp the carb too or is this the carb for the 107 with jetting for the 107 . i know its a 125 the motor says sdg and 120cm on the head and the motor vin came back pro mini .. butt i guess ill end up being on my own on this unless somone knows the jetting stock on the 125 motors and what the jettin on the 107 is .. im gona try to call sdg back again the guy said he would have to look further to get me the info i need .. kind of a headache ... butt thanx all who had input and tried to help me ..
 

Kurlon

Active Member
Joined
Feb 6, 2010
Messages
43
Reaction score
2
Location
North Eastern US
The 107 and 120 motors are REAL easy to tell apart...

Recent image by yamaha2008yz250f on Photobucket

See how the head is HUGE, with a cam cover that is held on via two bolts and '3V' engraved on it? That's a 107cc SDG 3 valver. If you don't have that head, it's the 120cc Lifan.

On the bikes, if it's got conventional forks up front it's a Speed or Lil mini. Marzocchi Shivers, Pro Mini.

SDG USA
SDG USA
SDG USA

I don't think I've ever actually seen a lil mini in the wild.

Back to the original question, jetting. Screw OEM jetting, it was too lean to begin with. Pull your carb, find out what it's got for a main and pilot and we'll start from there.
 

MINIMOTA

Member
Joined
Feb 1, 2012
Messages
20
Reaction score
0
ya .. i have the 120 lifan motor then .. it dont look like the picture u posted .. its simalar butt says 120cm on the head of the motor and the cases say sdg .. and jettin yess i gotta be lean .. and i know the carb is a mikuni i have a 107.5 main and a 20 pilot and i had to se the needle to the last clip position to get it to run any better .. thats what im at now and still not right .. and fuel screw i have out 2 and half turns ... starts 1st kick no choke .. runs ok butt i know its not right and it buggs me .. im thinkin 110 main and jump my pilot up butt i dont know where to go with the pilot how hight should i go .. seeing i had to drop the needle from middle position to the last to make it a lil but better .. i wana have the clip up in the middle where it should be .. . and it has a uni foam filter and thats clean plugs fine .. its jetting .. should i go higher on the main or no .. it doesnt pop or backfire on decell its smooth and top end doesnt sputter its that mid and bottom stutter butt more on the top cant hurt .. .. thanks
 

sean01

Legend Spanner Spinner
Joined
May 27, 2007
Messages
5,934
Reaction score
120
Location
burpengary, brisbane
good to hear you got near perfect now...

stock mikuni 26mm (really 22mm) jetting means squat, different altitude and climates change the tune.. but from memory 20 pilot and 98/102 main jet.. there also should be a plastic washer under the needle, if there isnt no biggie just means if your ever needing to raise the needle fully you'll never get it quiet right untill you put the washer back in..

also good to hear about the oil, we see so many here using the wrong oil and it takes all of about 20 minutes thrashing to kill a clutch. then you get the people that use 4 stroke stationary engine oil, that crap will glaze and engine just as quick lol...

110 main is way to big... just cause your on the bottom neelde clip doesnt mean you need a bigger main jet.. you need the next size up needle..

but it is not uncommon to get the tune on the bottom needle clip, middle clip is just a base setting..

sounds like you have pretty spot on, i wouldnt be mucking with it anymore.. your already over main jetted
 

MINIMOTA

Member
Joined
Feb 1, 2012
Messages
20
Reaction score
0
@sean yes i thought 110 would be big but theres 107 in there now so maybe the main ill leave alone or maybe go down an play with my pilot jet and see what happens .. thats why i thought it was rich from the get go the fumes that come out the exhaust will burn ur eyes u smell the fuel like crazy butt then i move the needle down and let it have more fuel it runs better thats why i was stummped something isnt right .. and ya i have the lil nylon washer under the needle too so that atleast helps narrow it .. im usually real good with tuning my quads butt there all kehin and i know stock jets sizes so i can go from stock numbers to get it more spot on .. to be honest ive never had to touch a pilot jet unless it was upping it in winter to get rid of hard starts on the hondas .. usually bump the main and move needle one clip and whamm good to go .. butt this things a ghost .. sdg doesnt call me back either .. im in rhode island in the us so im north east mass border .. im picky and i wont go out an give the thing a good ride till i know im spot on maybe ocd idk butt i have to get this thing down to ride it .. its all stock .. stock exhaust no cams no bigger carb just the uni filter and they come with a foam filter .. so im thinking get stock numbers would help .. butt thats a mistery itself .. lol i spend more time on this forum then on my bike and i just got it usually im on it till i break something then on forums for help if i need it .. or to provide help to others if i can .. butt im at ? with it right now ..
 

sean01

Legend Spanner Spinner
Joined
May 27, 2007
Messages
5,934
Reaction score
120
Location
burpengary, brisbane
107 isnt a standard 26mm china mikuni main jet, well none that iv ever come across.. maybe thats what the carb is off, maybe the bike needed a carb under warranty when purchased and they were gave just what they had.. who knows..but i do know that 107 SHOULDN't be in there lol

is that a typo or are you thinking backwards...
moving the needle down leans it out not makes it rich but moving the clip down does

iv given stock jetting above, not sure what more you want... i work for a pitbike company so i pretty much know what should be in there. even 30mm china mikuni carbs come with smaller than a 107 main

are you doing plug chops? where in the throttle range doesnt it feel right?
maybe your expecting too much out of the carb... or maybe your doing it all backwards...
biggest pain is tuning the mixture. unless you have the proper right angled tool you'll struggle..

several posts ago you say you've got it pretty much spot on but because the needle isn't in the middle you say its not right, then you go on saying that you tune quads by moving the needle so realistically going by what your saying here the quads shouldnt be great either....

im not having a go at you so please dont think that, im just trying to get what your looking...plus we cant see/hear or feel how the bike is acting...

one last thing to add to my dribble..
spark plug been replaced yet? all this richness could of washed the plug a bit...
not sure if its been asked yet but what about the rest of the engine components!!
compression
valve clearance
exhaust gasket
stator output
coil output

anyways hope you work it out and please let us know what you end up doing..
 

MINIMOTA

Member
Joined
Feb 1, 2012
Messages
20
Reaction score
0
ok yes typo i move the clip down rising the needle allowing more fuel to flow threw the main jet .. needle is saposed to regulate 1/4 to full throttle along with the proper main jet in there .. pilot and fuel screw regulate idle and up to quarter throttle am i correct .. ?.. also .. the atvs i work on have manuals are made by big bike companys such as honda kawai yamaha .. i once had a 98 yamaha banshee the kid threw a set of flatside carbs on it didnt know what jets or anything .. i went back to stock jettin numbers and carbs then jetted up on the main and moved the needle clip down allowing more fuel to rip threw there seeing it had fmf sst pipes and open airbox with k&n and did a plug chop and was spot on .. ran great no sputter anymore nothing .. thats what im getting at.. also not a chop at you butt u didnt give me the stock jetting that belongs to the bike u gave me a range and an idea of what the carb it self not attatched to this specific motor .. sometimes i could take that highest rand and still be off and not run right .. or take the lowest and then still be off butt lean and burn up valve seals and rings .. i was just wondering if anyone had this bike .. not you or anyone in particual just anyone and knew what the bikes ran in there carbs to see if maybe i was running maybe one of those china junker carbs or jets .. thats all i ment .. im 100% thankfull for all help and input u have given and the time u have taken to think it threw and try to help .. .. and on the main .. im willing to bet ur 100 percent right its prolly way to rich .. ive yet to hear of anyone on here or other forums running a main near that size at my cc .. and the plugs been changed 2 times now .. tryed the plug u said witch is what i had in the bike .. top end she is fine .. its bottom to half or lets say ur running threw a track and down shift into a burm then try to romp out of the corner its sluggish then picks up like crazy .. his has crazy spark .. valves are in clearence and timings spot on motor purrs .. just hits rought spots down low where its to little .. so im gona bump the pilot when the moto shop opens tomorrow they bloow there close main days sun and monday . and ill get back to let ya know .. butt all seriousness asside thanks and dont be afraid to get on me if im making no sence ... im no baby i can take it if ur somone who is trying to help .. cant be mad if i brain fart and u catch me on it ..haha
 
Last edited:

my67xr

Miniriders Legend and Master Spanner Spinning Mode
Joined
Jul 29, 2010
Messages
11,982
Reaction score
79
Location
South Australia
ok yes typo i move the clip down rising the needle allowing more fuel to flow threw the main jet .. needle is saposed to regulate 1/4 to full throttle along with the proper main jet in there .. pilot and fuel screw regulate idle and up to quarter throttle am i correct .. ?.. also .. the atvs i work on have manuals are made by big bike companys such as honda kawai yamaha .. i once had a 98 yamaha banshee the kid threw a set of flatside carbs on it didnt know what jets or anything .. i went back to stock jettin numbers and carbs then jetted up on the main and moved the needle clip down allowing more fuel to rip threw there seeing it had fmf sst pipes and open airbox with k&n and did a plug chop and was spot on .. ran great no sputter anymore nothing .. thats what im getting at.. also not a chop at you butt u didnt give me the stock jetting that belongs to the bike u gave me a range and an idea of what the carb it self not attatched to this specific motor .. sometimes i could take that highest rand and still be off and not run right .. or take the lowest and then still be off butt lean and burn up valve seals and rings .. i was just wondering if anyone had this bike .. not you or anyone in particual just anyone and knew what the bikes ran in there carbs to see if maybe i was running maybe one of those china junker carbs or jets .. thats all i ment .. im 100% thankfull for all help and input u have given and the time u have taken to think it threw and try to help .. .. and on the main .. im willing to bet ur 100 percent right its prolly way to rich .. ive yet to hear of anyone on here or other forums running a main near that size at my cc .. and the plugs been changed 2 times now .. tryed the plug u said witch is what i had in the bike .. top end she is fine .. its bottom to half or lets say ur running threw a track and down shift into a burm then try to romp out of the corner its sluggish then picks up like crazy .. his has crazy spark .. valves are in clearence and timings spot on motor purrs .. just hits rought spots down low where its to little .. so im gona bump the pilot when the moto shop opens tomorrow they bloow there close main days sun and monday . and ill get back to let ya know .. butt all seriousness asside thanks and dont be afraid to get on me if im making no sence ... im no baby i can take it if ur somone who is trying to help .. cant be mad if i brain fart and u catch me on it ..haha
my head hurts now after reading that :confused ::confused-smiley-014
after all of that, what was the question?
 

eichkay

Well-Known Member
Joined
Sep 10, 2006
Messages
1,406
Reaction score
16
Location
Perth Australia
my head hurts now after reading that :confused ::confused-smiley-014
after all of that, what was the question?

there were questions in there but they seemed to be answered by them selves

@ Minimota

• Id like to know what jets you have on hand for this carbi ?
• How's the bike at WOT ?
• What temp plug is in the bike ?
• what the ground strap reading on the plug like ?
 

MINIMOTA

Member
Joined
Feb 1, 2012
Messages
20
Reaction score
0
my head hurts to when i proof read all i typed lol .. but anyways i got on the phone again talked to a guy at sdg he usto build them and race them.. found out they stopped producing them in 2008 .. they sold the bikes and parts and prints for everything to somone else .. the bike i have is speed mini with the pro mini 125 motor .. now the carb i have is only 20 mm thats what both speed mini and pro came with mikuni carbs .. jetting is saposed to be 100 main jet 15 pilot and 3rd middle grove for the needle .. he told me somone probly swapped the motor and kept the 107 carbs jetting on it .. and i guess he said the speed mini had to use bigger jetts due to the 3 valve and bigger head .. kinda like sean was explaining to me .. and and only 1 and half turn out on the fuel screw for the factory jetting .. with no modds the 107 woulda been 2 turns and bigger main and 20 pilot and with a pipe on a 107 the 107 main would make sence he said .. he threw a cam in on his pro mini and had to jump 2 sizes and he said this and most minis when jettin saposed to jump by 2 on the mains .. so being said .. im gona put the bike to 100 main and leave the 20 pilot and back the needle to middle gove and see and ill report back with results .. thanks guys .. much apreciation ..
 

MINIMOTA

Member
Joined
Feb 1, 2012
Messages
20
Reaction score
0
Chaparral Motorsports is who took over whatever sdg had and they are who ill have to get parts from i guess ,, and they also confirmed to me in an email what the guy from sdg said 100 main 15 -17 pilot and 1 and half turns out on fuel screw i had this thing 3 turns out when i got it then brought it to 2 and half out so tonite ill put the needle back to middle and one and half turns out on the screw then tomorrow get some jets for the main and pilot .. see what happends ,..
 

MINIMOTA

Member
Joined
Feb 1, 2012
Messages
20
Reaction score
0
what the flip ..

ok .. got ahold of a family friend who owns champion motorsports .. he had a bunch of jets .. just got in from funkin with the jeting .. brought the main to a 102 and needle to 3rd notch and fuel screw 2 turns out and it would start idle butt as soon as i touched the throttle it died .. couldnt even do a plug chop seeing it wouldnt move .. so we moved needle down to last position same thing .. then went to a 105 main got a lil better butt stummbled alot .. then went back to the damn 107 i had in it and middle grove on the needle and pilot 1 and half turns out ran better butt still poop on the bottom end ,,,, then moved the needle again to the last position and the 107.5 main jet and she purrs no pop no stumble seems right .. butt the bottom clip position makes me think maybe up the main to a 110 and go to the 3rd needle clip position .. .. when i checked the plug it was dark not brown not white maybe charcoal black butt not wet of fouled .. .... any input now?.. also why the heck is my lil 125 motor needing a 107 or higher jet when everyone says should only need 102 max .. .. exhaust fumes are strong like im running race fuel strong smell of gas .. butt runs better with more gas then less .. and its only 93 octane in there ..



and yes i used mikuni jets didnt use wrong jets in the bike .. not kehin or other jets .. it was a mikuni kit had a crap load to play with .. butt no 110 ony 105 was his highest .. he said he doesnt use nor sell many bigger then that even he is confused .. he said it shouldnt need that much fuel .. maybe theres motor work done ?
 
Last edited:

sean01

Legend Spanner Spinner
Joined
May 27, 2007
Messages
5,934
Reaction score
120
Location
burpengary, brisbane
hmmm, yeah maybe there is work done to the motor..

id like to see a pic of this carb and engine, maybe even thro the engine number up.. and pics of the jets your using...

a few posts back you said something about a china junker carb!! are you not aware that you are more than likely using that type carb lol...

as for your jets, is the dude you got the extra jets from a japanese or china bike retailer.. im yet to see china made jets within the same numbering specs as japanese..

also do yourself a favor and put some decent fuel in it. and not octane booster. 95 at least, no wonder you need big jets lol..
 

Latest posts

Top