You can also try a Delorto VHSA32 which is a 32mm carb used on the TZR 4DL which shares the same engine as the DT125R.

Only putting it out there, if it were me, I'd go for a tm28ss which is standard on DT125R from 1991 as Darty says.

The jetting changed in around 1996 as well but that will depend on the conditions of where you ride so you'll have to experiment with that.

Yup, get it sorted with a new floatvlave and seat.

DOH! didn't look at the back of the haynes manual (pg140) where they added later bike models. From 2004 onwards the main jet was 210 and pilot was 17.5 - so my bike was set up correctly! Problem now is my jet needle is a little bent and shows excessive wear on the bent side which means I need to replace my needle and needle jet ( 5j40 and q2m(939) ) but I can't find those anywhere on the web.

Yeah which is why it was a side note rather than a big point. Still not something I would do personally.

@mezzaaa rough inlet helps with fuel atomisation. This helps to burn the combustible mix properly.

However this only occurs once the fuel and air are together. Polishing the bell mouth helps draw air in. You want to be doing that as fast as possible.

@Calum Thanks 😃

@MIGHTYMAN couldn't comment other than its a round slide carb which is a no no for performance.

try adjusting air/fuel mixture this should help mate i had a similar problem with mine so got it cheap he thought it had bad problem. i will probably get around to buying after market crab as mine has a small crack on the carburettor body i have my tick over screw screwed in
all the way

@MIGHTYMAN said in Is upsetting necessary?:

4FU from Germany.

Not talking about the cylinder pal. Was talking about the Chassis/Engine code. Not that it makes too much difference but the 4DL's are ever so slightly different internally compared to the 3BN.

Finding out it's a 4GW model will tell you what spec the engine was, I.E 4DL ran VHSA carbs over the 3BNs Mikuni TMX28. Stuff like that just tells you a bit more about the problem.

Yea tried the needle position when all was standard but the leaner I put it the worse it ran the richer the better but still didn't cure the hesitation.

Thanks for the help.

Ah - thanks, now it starts to make sense. Been fiddling with it this afternoon and it seems to run great with a 260 main jet and 30 pilot jet - the only thing I wanted to achieve is reliabilty, making sure it not runs to lean, not to maximize performance..

Respect!

thanks callum the carbs all working fine now but cant seem to get the powervalve set right now...