DT125R ARCHIVE

Reef · Guru

CARB PROBLEM, BIGGER PROBLEMS :/ HELPPP

Cameron · Guru

RE: Carb problem after putting in new jet

Reef · Guru

Ay that's all sorted, it was the float, thanks :)

New problem tho;

Ok so today I fitted a 240 jet (with the needle in the middle notch) as it was running lean with the 210 jet, full dep, snorkel on/off etc but it's running so bad and I need the forums help :)

What's its doing now is a couple of things;

1st thing - I noticed that there was a hissing noise coming from the carb area after we changed the jet (had a mate give me a hand), sounded like it was sucking in air from somewhere but mate whos good with bikes wasn't having none of it and saying everything connected to the carb is a nice secure, sealed fit, and he said changing the jet your likely to hear it change in sound... Lol I doubt it??

2nd - its running lean still even after jumping from the 240, now I'm thinking this hissing noise is the reason for it to be running lean still

3rd - idle is so bad, there is no idle?? To keep it running you have to have it idling really high by adjusting the idle screw, and even then when stationary its really boggy and if I don't keep blipping the throttle it cuts out, any suggestions?? Also for some reason when stationary it will idle really high and then after about 10 seconds the revs drop massively?? See mate was saying if it was because of a or leak that idle would be constantly high and not drop so I'm puzzled

4th - even though it was warm it didn't want to start without the choke, or even sometimes without blipping the throttle??

Oh yeah if it helps I must mention how he put the needle back into the middle notch as he said that's where all needles are positioned from stock on any make carb??

It's really annoying tho as I was hoping to get this sorted but he doesn't want to touch it any more and says it needs to be dynoed to get it set up right, which I don't think is needed as I'm sure with the forums input I'll be able to get it running nicely, and the worst thing is he says it's running perfect even though it running a little lean, failing to idle, needs to idle high to keep just running to a degree etc.. Lol :/ So yeah I need your help lads, really wanna get mod 2 sorted this year but this is holding me back now

So yeah where to start, will appreciate any advice

NEV · Guru

RE: CARB PROBLEM, BIGGER PROBLEMS :/ HELPPP

Reef · Guru

Ay I'll check that out, thanks, do ya think this could resolve all the problems if it is that

Reef · Guru

Will have a look at the o rings tommorow after I finish work or Sunday but does anyone else have any suggestions on why these problems are occurring and how to sort them/some of them, really need the dt for mod 2 but until it's sorted I'm kinda stuck

So yeah, please if anyone can help I would appreciate, mate doesnt wanna sort it out now so I'm gonna have to sort it out myself, or of worse comes to worst and it doesn't get sorted from the suggestions on here I'll have to think about paying someone qualified to sort it out, can't live with it knowing it's running lean and that is doesn't idle properly :/ lol

Cheers

Reef · Guru

So just to confirm no one can suggest anything else so all I have to go in is the possibility of lost or damaged o rings?? :)

Please, If you can suggest anything else to help resolve these problems please let me know

Thanks

FunkeyMunkeyDavid · Guru

start from scratch and recheck your every move fella. out of interest,have you done the reed block mod? that can cause leaks,mine needs instant gasket to seal it hmm and defo check the magneto side crank seal with wd40

toadymc · DTR Respected Member

just check every thing you took off have you checked the yeis bottles on the air intake rubbers are on proply and how did you remove your carb? The re's seem a lot fiddlier to get off than the dtr's iv watched a vid on youtube an he pops it straight out in about a min where as i just cant do it theres too much stuff in the way i strip nearly the hole bike, seat pannels tank yeis bottles battery batteryholder and then slide air box bak above the rear wheel i dont mind doin it this way though done it about 6 times an it seems a bit safer you dont have to bend things as much and yeah your bike will still be running a bit lean. the 240 main jet with your set up should be right but the standard re's pilot jet is too small the mix screw is set at a quater of a turn out way too lean your bike can blow up just as easy from a lean pilot circuit as you can main . My setup is full dep, pipercross air filter, and snorkel in 250 main jet ,25 pilot jet, mixture screw out to 1 and a quater maybe a little nip more,2nd notch on the needle think i may need to go down to 3rd tho but il test that soon.

FunkeyMunkeyDavid · Guru

the crank seal your looking for is behind the magneto (remove the left hand engine cover,as your sat on the bike) and you'll see this big round thing

images?q=tbn:ANd9GcQqRcJph6H8qJwjdt4TCNbWbAcFNee7lCc4ZdOKBXqt9ZwEae0S

with the bike running get a wd40 can (with the little tube on) and spray it behind the moving magneto (watch your fingers lol) if it revs higher when you spray it the seals shot hmm

-- Edited by FunkeyMunkeyDavid on Saturday 6th of October 2012 07:32:54 PM

tripr · Guru

whack the needle clip in 4th slot from the top for a start m8 try that

bobc · DTR Respected Member

First job is to check for air leaks everywhere particularly knackered crank seals, unless you're confident they are ok change them as no amount of jetting etc will compensate for the worn seals . I would then rebuild the carb , replacing all gaskets and O rings and needle valve , unless you have changed them recently . Last week my bike started revving all over the place on idle and it was the O ring on the choke ,looked ok but changing it fixed it .

Reef · Guru

Hello lads, appreciate your help, fmd, nope not done the reed mod, as for the side crank seal I'll have to look that up unless you can describe what it looks like, see not too clued up yet, and just looked in manual but only instructions and no pictures

Erm as it wasnt me doing the work I was only watching but Ill have a look at the bottles to see if they've been put in properly as well as everything else, might just start again with it. We didn't remove everything to get to the carb, just the seat and the tank and the two bottles and like you said its so much hassle so when I look into it tommorow (if it's not raining) I'll strip the bike down further to get to it like the way you do :) oh really, pilot jet standard is a 17.5 do what should I try with the 240 and no snorkel please?? And where can I get one from please?? And as for the idle screw what should I set it as now mate ,including with the different sized pilot jet??

As for the needle tripr if I remember correctly only had 3 slots and mate left it in the middle?? Should this be changed to having the needle clip in the top slot of the needle or the bottom??

Thanks again lads

Noob

Reef · Guru

And thanks bob, I'll do that if everything else doesn't work out, need to know where the crank seal is tho, as for this possible air leak because of the hissing, could it be an air leak thinking about it?? See as mentioned before in idle now if you leave it after using the throttle and stationary it will idle 3x as much as its meant to but about 10 seconds later the revs drop significantly??

toadymc · DTR Respected Member

Yep standard re carbs only have 3 notches on the needle. And yeah its 17.5 pilot jet std i would say 25 but u will have too test it your self . If u do want a 25 just go to yamaha and order one for a 2003 or search ebay i couldnt find one at the time tho and with a 25 pilot you want the screw out to about 1 an 1/4 out again this needs too be tested but dont bring it out without puttin a bigger pilot jet in as it will be lean and wont run right

Reef · Guru

Ay so that's where it is, cheers mate, yeah seen the flywheel enough times before when I sat there for years trying a get my dtr started, but yeah I'll do that tommorow mate, thanks, hopefully I can get it running right again :)

FunkeyMunkeyDavid · Guru

lol everytime i say flywheel people are like " wot the magneto" lol but yeah give that a go. costs niche and takes ten mins smile

bobc · DTR Respected Member

Page 197 of the service manual shows both oil seals , it does not show you how to change crank oil seals with the engine in .
here's a guide I used from www.yamahait.com.au, worth joining this site there is a lot of info on it , look on the DT200 section as it is the same , hardly any 125s in Oz

you will need a flywheel puller. a rattle gun (impact wrench) would be very helpful! I recommend using Yamaha seals for this not patterns

Flywheel Side

1. Take Cover Off
2. Remove flywheel nut (Rattle gun works best here)
3. try to remove the washer behind the nut (an air cannon works good)
4. insert your flywheel puller (left hand threads)
5. remove flywheel (watch out for the key on the shaft, if you cant find it check the magnets in the flywheel)
6. take note of stators position (make marks if you need to!!)
7. Remove stator
8. remove the seal (or whats left of it) i used a small screw, screwed it in the old seal and took pliers and pulled the screw & seal out.
9. install new seal (a socket or piece of pipe that fits the seal works well)
10. Install stator (make sure its in the same spot as before or your timing will be off!)
11. put the key in the shaft and put the flywheel on.
12. Insert washer and nut and tighten the nut (tighten it good! mine wasnt tight enough and the flywheel came off a little and snapped the key!)

Clutch Side

1. Drain Transmission Oil
2. Remove Clutch Cover
3. Remove Clutch Spring Bolts
4. Remove Clutch Springs (measure for wear)
5. Remove Clutch Plates (measure for wear)
6. Straighten Lock Washer Tab
7. Remove Locknut (you need to hold the clutch when you do this there is a yamaha tool that will do this but i used a pair of vise-grip clamps to hold it)
Or Use an off cut strip of aluminium to jamb the gear and undo it with a breaker bar. Reverse that to do it up but with a torque wench
8. Remove Lock Washer
9. Remove Clutch Boss (the inner part)
10. Remove Thrust washer & Clutch housing (the outer bigger part)
11. Remove Spacer & Another Thrust Washer
12. Remove The Primary Drive Gear Nut - The nut on the CRANKSHAFT (if your top end is on insert some SOFT rope in the sparkplug hole so the piston cant go to TDC and therefore cant complete a stroke so the engine wont move. if your top end is off, put something through the piston rod so it cant complete a stroke OR hold the flywheel. then take the nut off, i used a rattle gun here)
13. Remove washer
14. Remove Primary Drive Gear
15. Remove Straight Key
16. Remove Seal Holder
17. Remove Old Oil Seal
18. Install New Oil Seal (watch out she can be a pain to get in )
19. Reverse These Steps to put it back together!!!

-- Edited by bobc on Sunday 7th of October 2012 01:31:22 PM

tripr · Guru

yeah didnt know the re's carb needle was different go bottom notch to richen up your mix a bit

stick a picture up of the spark plug new m8 when you do check it,,

And do ya not know someone whos got another carb they could let you try out

-- Edited by tripr on Sunday 7th of October 2012 06:26:45 PM

tripr · Guru

personally id try my old exhauast 1st to see if it is the pipe causing it needing rejetting , then id try a diff carb to see if that sorts it ,failing that then id try a 260 jet an 20 or 25 pilot jet an a new plug

my 170 runs a lovley plug colour on 260 main standard pilot

ill tell ya if i need to rejet when i get the dep expanny

-- Edited by tripr on Sunday 7th of October 2012 09:21:45 PM

Reef · Guru

Sorry toadymc, never saw your message as was writing my last one when you sent it, anyway thanks, I will order one tommorow and after fitting it I'll follow all the instructions given above to try solving some of the other problems :) and then go for a ride and do a ply chop to see if it needs smaller or bigger pilot

;) yeah I will deffo check the seal But I'm hoping it hasn't gone and would be a bit strange as these problems only started occurring after changing the jet, but like you say it's worth checking

And thanks again bob for those instructions on how to change the seal if it's gone

So should I not also change the needle to suit these changes or should I leave it for the time being and see if all the problems can be resolved without it??

Once again, you don't know how much I appreciate all your help and the amount your putting in to help try to resolve these problems, so yeah thank you, and I will start working on it Wednesday hopefully as had work all day and mon/tues I have college all day

Reef · Guru

Ay will do, nope but I've actually got a dtx carb which I could try, when would you say to try that, 1st thing to see if it's any different

Cameron · Guru

Quick question, how long's it been running lean and was it ok before you touched it? The carb can't just start running lean all of a sudden if you haven't touched it. Make sure you haven't split the inlet manifold as I snapped mine clean off lol.

Reef · Guru

not long, and it never been running that lean supposedly, the reason why it is running slightly and i mean slightly lean is because I fitted a DEP xpanny which replaced my standard, and therefore that's why i had to jet it, but it was running a tad rich beforehand, which suggests that it was solely the pipe at first which affected how it was running,

and ok, ill check that as well thanks ;) im determined to sort this out ;)

Reef · Guru

Ay the standard has a massive hole in it, which will probably affect plug colours i guess, and its way too noisy to be taking it out, but yeah, what ill do i think from that and everything else is to order a new bigger pilot jet, clean the dtx carb with carb cleaner, put the new pilot jet and main jet in it, change idle settings to how toadymc recommended and see how its running after that, probably my best bet first ay, least if its too much and it runs too rich i can go from there. if it still comes to it where its hissing around that area as well as if it still runs poor ill strip it down and look into doing everything suggested

Reef · Guru

Hello lads, me again ;) haha

Whilst waiting for a new different sized pilot jet to come in I thought it might be a good idea to start stripping down the dtx carb to see how everything is put in to help save time when i come to fit it to my existing carb; but I'm stuck already lol, and ive only just took one of the covers off.

So im trying to remove the pilot jet, after looking into a service manual and the carb diagrams in this section I know its found in this part of the carb but how do i get to it and where is it, I'm baffled as one diagram shows one thing and another shows different, Heres where I've got to??

And oh yeah how do i get this jet needle holder to go back into the tubing lol?? it seems to just slip out when i removed it, am i supposed to squeeze it in?? lol

Cheers ;)

FunkeyMunkeyDavid · Guru

1st pic you put on,the pilot jet is in the hole above where the main jet was (little round brass thing) screws out with a long slotted screwdriver. same pic also shows the screw and plate the hold the needle jet in place. blow down every tube you can see while its apart,make sure they're clear. you get a varnish-like gunk build up in them,plays havoc with the way your bike runs hmm

Reef · Guru

Ay thanks mate, removed the pilot jet now, some of those diagrams dont make it easy

"same pic also shows the screw and plate the hold the needle jet in place" - Cant see that mate at all haha??? huh?? how does the jet needle holder sit in that tube which holds the main jet?

Seiki · Admin

Needle holder just slips back in the hole with a little persuasion

Reef · Guru

thanks seiki :)