tm33 advice HELP!
#1
04-21-2007, 11:48 PM
tm33 advice HELP!
Hi guys
Ifound myself a mikuni tm33 pumper and have been deep into the toolbox for the last couple of days making it fit, having done so i now find the bike runs like a bag'o'****e with it on. I cant get a decent tick-over, it grumbles and pops at low rpm (cant get it below 3000rpm) but seems to clear out if its given some air by opening the throttle. my first instinct was an air leak some where, but nothing, stripped the carb loads of time now and everything looks good and all passages are clear. Nothing i have tried has worked, how can an object bring so much pain instead of the advertised pleasure, but the Hot post of the day cheered me up
canany of you guys with pumper carbs fitted possibly post up your jet and needle sizes for me to compare.
what i have got,
Needle J2525
Main jet 127.5
Pilot jet 37.5
Main air jet 0.7
Pilot air jet 1.1
air screw out 1.5 turns
my instinct is that most are probably ok, but the needle is the one thats bugging me as i don't think its even a mikuni number.
The FCR37 is still in the back of the garage but it will require some serious engineering to make it fit, but i will, one day!
thanks in advance
Simon L
Ifound myself a mikuni tm33 pumper and have been deep into the toolbox for the last couple of days making it fit, having done so i now find the bike runs like a bag'o'****e with it on. I cant get a decent tick-over, it grumbles and pops at low rpm (cant get it below 3000rpm) but seems to clear out if its given some air by opening the throttle. my first instinct was an air leak some where, but nothing, stripped the carb loads of time now and everything looks good and all passages are clear. Nothing i have tried has worked, how can an object bring so much pain instead of the advertised pleasure, but the Hot post of the day cheered me up
canany of you guys with pumper carbs fitted possibly post up your jet and needle sizes for me to compare.
what i have got,
Needle J2525
Main jet 127.5
Pilot jet 37.5
Main air jet 0.7
Pilot air jet 1.1
air screw out 1.5 turns
my instinct is that most are probably ok, but the needle is the one thats bugging me as i don't think its even a mikuni number.
The FCR37 is still in the back of the garage but it will require some serious engineering to make it fit, but i will, one day!
thanks in advance
Simon L
#2
04-22-2007, 01:16 AM
Guest
Posts: n/a
RE: tm33 advice HELP!
tm33 is pretty small. the oem is a 34. i know nothing about pumper carbs. there are accelerator pumps, jets, etc. that could be the culprit. i'd work on the fcr37 if i were you. that with a big bore kit and you'd have some serious wheelie power. the 33, imo, is too small for the bike.
#3
04-22-2007, 04:40 AM
RE: tm33 advice HELP!
ORIGINAL: britboard
Hi guys
Ifound myself a mikuni tm33 pumper and have been deep into the toolbox for the last couple of days making it fit, having done so i now find the bike runs like a bag'o'****e with it on. I cant get a decent tick-over, it grumbles and pops at low rpm (cant get it below 3000rpm) but seems to clear out if its given some air by opening the throttle. my first instinct was an air leak some where, but nothing, stripped the carb loads of time now and everything looks good and all passages are clear. Nothing i have tried has worked, how can an object bring so much pain instead of the advertised pleasure, but the Hot post of the day cheered me up
canany of you guys with pumper carbs fitted possibly post up your jet and needle sizes for me to compare.
what i have got,
Needle J2525
Main jet 127.5
Pilot jet 37.5
Main air jet 0.7
Pilot air jet 1.1
air screw out 1.5 turns
my instinct is that most are probably ok, but the needle is the one thats bugging me as i don't think its even a mikuni number.
The FCR37 is still in the back of the garage but it will require some serious engineering to make it fit, but i will, one day!
thanks in advance
Simon L
Hi guys
Ifound myself a mikuni tm33 pumper and have been deep into the toolbox for the last couple of days making it fit, having done so i now find the bike runs like a bag'o'****e with it on. I cant get a decent tick-over, it grumbles and pops at low rpm (cant get it below 3000rpm) but seems to clear out if its given some air by opening the throttle. my first instinct was an air leak some where, but nothing, stripped the carb loads of time now and everything looks good and all passages are clear. Nothing i have tried has worked, how can an object bring so much pain instead of the advertised pleasure, but the Hot post of the day cheered me up
canany of you guys with pumper carbs fitted possibly post up your jet and needle sizes for me to compare.
what i have got,
Needle J2525
Main jet 127.5
Pilot jet 37.5
Main air jet 0.7
Pilot air jet 1.1
air screw out 1.5 turns
my instinct is that most are probably ok, but the needle is the one thats bugging me as i don't think its even a mikuni number.
The FCR37 is still in the back of the garage but it will require some serious engineering to make it fit, but i will, one day!
thanks in advance
Simon L
#4
04-22-2007, 05:53 PM
RE: tm33 advice HELP!
Iowaguy, "tm33 is pretty small. the oem is a 34", the oem for my bike is a 32mm surprisingly.
tremor38, its a 93 klx 250r which is the enduro race version with a 300cc conversion, so no smog gear etc airbox lid is on but with a huge hole on top to try to keep the induction noise down, standard exhaust (will change eventually) air screw makes a difference if i wind it in but only makes it rev harder below 1.5 turns. I'm thinking the needle and needle jet are all wrong as there is a lot of play even with the needle fully home i would of thought about maybe 0.1mm clearance would be correctbut i've got a lot more than that and maybe that is letting by fuel, it seems to clear out when i give it some beans and its running on main jet but it sound like its choking up at low revs lots of (black smoke and a black plug) all the other jets are brand new, so i think the next step is needle and needle jet to eliminate those.
Simon L
[IMG]local://upfiles/4476/D71F4A565DEC499DACCF26B168633CBF.jpg[/IMG]
tremor38, its a 93 klx 250r which is the enduro race version with a 300cc conversion, so no smog gear etc airbox lid is on but with a huge hole on top to try to keep the induction noise down, standard exhaust (will change eventually) air screw makes a difference if i wind it in but only makes it rev harder below 1.5 turns. I'm thinking the needle and needle jet are all wrong as there is a lot of play even with the needle fully home i would of thought about maybe 0.1mm clearance would be correctbut i've got a lot more than that and maybe that is letting by fuel, it seems to clear out when i give it some beans and its running on main jet but it sound like its choking up at low revs lots of (black smoke and a black plug) all the other jets are brand new, so i think the next step is needle and needle jet to eliminate those.
Simon L
[IMG]local://upfiles/4476/D71F4A565DEC499DACCF26B168633CBF.jpg[/IMG]
#5
04-23-2007, 04:56 PM
RE: tm33 advice HELP!
That sloppy needle sounds like a good place to start. No way you should be running that rich on the low end. Once you get that corrected, I think you will find that your main is a bit on thelean side....especially with the large airbox opening. Typically, people run the TM-33 with a MJ around 137.5 at sea level. You might even find something in the low to mid 140's more suitable for the 300cc jug.
Good luck!
Good luck!
#6
04-23-2007, 10:26 PM
RE: tm33 advice HELP!
More needles and jets ordered, just waiting for the postie now, i'll let you know the end result when i'm sorted.
(rant mode on)
must get itdone for the end of the month as thats when they open up all the green lanes here in England, the Tree-huggers here have a huge lobbying power and have twisted the goverments arm to closing them all to vehicle traffic over winter to stop us makingthemmuddy as they might get their shoes dirty,strange i know as they are all sat at home over winter,give them a few more years and i expect they will havefought to havethem all converted to footpaths which will us nowhere to go and then it will be back to the "catch me if you can attitude" cos i'm not selling my bike.
(rant mode off!) and relax
Simon L
(rant mode on)
must get itdone for the end of the month as thats when they open up all the green lanes here in England, the Tree-huggers here have a huge lobbying power and have twisted the goverments arm to closing them all to vehicle traffic over winter to stop us makingthemmuddy as they might get their shoes dirty,strange i know as they are all sat at home over winter,give them a few more years and i expect they will havefought to havethem all converted to footpaths which will us nowhere to go and then it will be back to the "catch me if you can attitude" cos i'm not selling my bike.
(rant mode off!) and relax
Simon L
Thread
Thread Starter
Forum
Replies
Last Post
