@ninja well duh 🙄 everyone knows ducks add horsepower

Go to motocarb select parts then tm and it’s no.2

Pictures are fine my end.

@calum okay thanks anyway mate I not sure it’s the overflow as I’m sure another pipe is the overflow but I’ll have to do some testing

@declan Not the hoses he's referring to.

@oldman There won't be much difference at wide open throttle, but at part throttle, the air can seep around the round slide, causing the fueling to be ever so slightly lean. It's not going to cause any issues, but that's a draw back of the round slide.

@declan The dellorto round slide probably has a power jet.

Brand new? Just lube it up, some aftermarked actually come preoiled. The stock isnt.
I've removed my snorkel, and added some protection to keep splashing water away from the intake.

Thats prob half your issue you wanna try get that sorted

Well it's broken isn't it.

I will ask that this is a separate problem and as such should be placed within the appropriate section, rather than reeds.

There are suppose to mount the exhaust to the frame with a rubber dampener. I guess Yamaha would be the place to get another one.

I never ran that one to be honest anyway.

@Jens-Eskildsen Absolutely, unless you have a DTRE CDI where it closes the port at 10K RPM. But earth the green and black wire behind the clocks and BOOM! Full power. Easiest bike to derestrict. It's like the Japs knew 😄

Measure both ends and length... This VM28 is 35 at the engine side, and 43mm at the air filter side and total length is abt 84mm.

I was going off float hight for a dtr when it was a Dt 2 mil difference and just realised the pod filter was batterd and was restricting air flow all good now cheers guys

Look at this on eBay http://www.ebay.com/itm/262372673935

That should be the top of the Mikuni carb

have bought a second hand normal dt inlet that im going to trim out.i have the original 4dl 32mm joiner and will try to join that to the original.i have ho idea of the needle size thats currently in it but she is fairly thin and pointy.ive went the opposite way to you and bought a u1 needle to try.the jet size is a 148.

@Louis-James I used the wr200 cables as was a direct swap and I plan to put all new on the wr anyway, It seemed to take far too much air in, maybe try again at some point I'll just have to order a handful of jets and have done with it

I managed to find a company that makes precision jets for mikuni carbs (KMT Products) haven't fitted the 250 yet (240 standard I think) but have now reset then tweaked my mix screw and idle slightly and it is running much better in the lower rev range, no bogging when dropping gears etc. Feels slightly 'held back' in the midrange though and the same at the top end of the revs, with a slight 'cough' at full throttle. Hopefully will have time to fit the 250 main and raise the needle slightly this weekend and see how that does. It also feels as though it's revving extremely high in 1st & 2nd (pinned pv) then taking longer for the revs to reach 6.5K (hit the power band) in 3rd and upwards. Bit of a strange one, definitely a fuelling issue I reckon though...

@vtrn_raptor post some pics mate

@vtrn_raptor You have just answered your own question there dude. Just like fire, combustion engine's require three elements to produce combustion or energy; Air + Fuel + Spark = Energy. If the mix is wrong then the combustion will be imbalanced. As long as your spark plug is fine you should be producing a good spark to ignite the fuel and air mixture. Did you fit a new spark plug after the rebuild? If not then I would recommend that you get a new one ASAP.

Too much fuel will cause the engine to run rich, with un-burnt fuel getting pumped out of the combustion chamber by the piston. Basically the mixture will be too wet. Too much air will cause the mixture to run lean aka dry. In effect too much air will dry out the mixture. Have you looked at the spark plug since the rebuild? Refer to a Haynes manual to check the colour of your spark plug? This will tell you if the mixture is correct or not? Adjust accordingly if required? If the mixture is fine then I would look at the timing next, perhaps the engine is miss-timed, which would give you a rough idle and poor running at RPM.

If your bike runs good with the choke ON, that's because you are adding fuel to the mixture, aka over-fueling, which tells us that your mixture is wrong. Perhaps it was poorly set-up by the previous owner, or there was an air leak due to the top-end or a gasket being worn. Now that you have an air tight barrel, your engine requires a different set-up, one which is as it should be.

If you don't have a Haynes manual for your bike then I would suggest that you get one ASAP. They are a wealth of info for home maintenance and have a great section's on diagnosing problems too. There well worth their weight in gold, plus there's always some for sale on ebay. 😉

@Raydt Yeah that's how you would test.

In fact WD40 everything whilst it's idling high will tell you if its an air leak.

Some times it can be something simple like throttle cable sticking too high.

Again I was just under the impression the float shut off the fuel to the bowl.

But obviously it's it's too high it'll shut off the fuel too early, and too low will cause it to overflow.