Runs with choke
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The only other thing I can think of air getting in isā¦
So the reed rubber bit where it goes onto the reed valve that has its own gasket doesnāt it the rubber bit, Iāve put a gasket onto that as itās got a reed spaced air wouldnāt get in there would it? Or would it be best to take that gasket out and just put it without as it is from factory?
Thanks
Thereās a gasket below the metal reed valve. None above (and between) the reed valve and rubber intake (it has its own seal). If youāve fitted one strip it down and try again. The inlet is the most likely cause for your symptomsā¦
Do you have much hands on experience with engines, or is this a first bike?
One of my first experiences with the dtr was an almost Invisible split in the rubber mount⦠-
Thereās a gasket below the metal reed valve. None above (and between) the reed valve and rubber intake (it has its own seal). If youāve fitted one strip it down and try again. The inlet is the most likely cause for your symptomsā¦
Do you have much hands on experience with engines, or is this a first bike?
One of my first experiences with the dtr was an almost Invisible split in the rubber mount⦠-
Have you changed the jetting, or is it the same as in the start of the thread?
210
.225
Ect?Iāll take the gasket off today mate, Iāve had a couple dts and mx bike Iāve always done rebuilds on but this one seems to be testing meā¦
Iām currently running 240 main
25 pilotWent for a ride on choke then turn choke off when moving goes for Abit then bogs when let off and try to use throttle again just bogs but flick the choke back up and runs again
Am I thinking itās lean?
Iām off to get some brake cleaner in a minute and going to test for leaks again
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Iāll take the gasket off today mate, Iāve had a couple dts and mx bike Iāve always done rebuilds on but this one seems to be testing meā¦
Iām currently running 240 main
25 pilotWent for a ride on choke then turn choke off when moving goes for Abit then bogs when let off and try to use throttle again just bogs but flick the choke back up and runs again
Am I thinking itās lean?
Iām off to get some brake cleaner in a minute and going to test for leaks again
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Itās definitely lean. Itās just where the fux itās taking unmetered air at? The power jet pipe is connected, yeah?
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Powerjet is connected, Iāve blasted brake cleaner around everywhere and no change in revs, Iām going to completely take the carb apart everything and clean and check everything
I had to ask, I honestly donāt think that youāre as big an idiot as me š I just donāt understand where an air leak big enough that changing the jetting as you have, has made no difference, can beā¦
Again, sorry, I have to ask! You are spraying and checking while the choke is off? When I sprayed even a tiny bit near where the leak was my engine stopped āhuntingā and settled down.
Yours will tick over without choke yes? But be all āfast & twangyā?There are only so many places air can enter unmetered
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I had to ask, I honestly donāt think that youāre as big an idiot as me š I just donāt understand where an air leak big enough that changing the jetting as you have, has made no difference, can beā¦
Again, sorry, I have to ask! You are spraying and checking while the choke is off? When I sprayed even a tiny bit near where the leak was my engine stopped āhuntingā and settled down.
Yours will tick over without choke yes? But be all āfast & twangyā?There are only so many places air can enter unmetered
Fixed it!!!
So airscrew didnāt have a o ring so put one in.
Also when I was checking air leaks nothing, so I thought Iād take carb out and check all rubbers, where the jubliee clip tightens up onto the carb on inlet there was a hairline crack under the clip which I only saw when I flexed it about. so put the carb back on and sprayed like 2mm away from the place I saw the crack and sure thing revved up. So thatās why I didnāt rev before when I sprayed because I had to be really really close to it!After all that š Iām glad though crazy how a tiny tiny little crack can do that but where it was hidden under the clip it didnāt pick up the brake cleaner until really close.
Thank you everyone been a couple of stressful days but thatās a win and learn something on the way
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Fixed it!!!
So airscrew didnāt have a o ring so put one in.
Also when I was checking air leaks nothing, so I thought Iād take carb out and check all rubbers, where the jubliee clip tightens up onto the carb on inlet there was a hairline crack under the clip which I only saw when I flexed it about. so put the carb back on and sprayed like 2mm away from the place I saw the crack and sure thing revved up. So thatās why I didnāt rev before when I sprayed because I had to be really really close to it!After all that š Iām glad though crazy how a tiny tiny little crack can do that but where it was hidden under the clip it didnāt pick up the brake cleaner until really close.
Thank you everyone been a couple of stressful days but thatās a win and learn something on the way
@OllieDTR Cool you've fixed it :+1: :+1: Here you go bud, DTRe 1D01-1D03 (2004-onwards) wiring diagram as discussed:

I'd still try those washers above and below the carb needle E-clip, stopping that moving up and down too much will be no bad thing. And here's a pic of my airbox when I sealed it up, this is why I like to take them out to do this so the part you've glued can sit on the bench horizontally while the glue goes off. While you've got the Seal-All out you can also replace the foam on the back of the filter element holder where it slides into the airbox as this is another thing "previous owners" miss, it rots out providing another route for dirt to get in. 5mm air filter foam is pretty cheap on eBay etc.

https://www.repairingproducts.co.uk/product/seal-all-gas-oil-resistant-adhesive/
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Fixed it!!!
So airscrew didnāt have a o ring so put one in.
Also when I was checking air leaks nothing, so I thought Iād take carb out and check all rubbers, where the jubliee clip tightens up onto the carb on inlet there was a hairline crack under the clip which I only saw when I flexed it about. so put the carb back on and sprayed like 2mm away from the place I saw the crack and sure thing revved up. So thatās why I didnāt rev before when I sprayed because I had to be really really close to it!After all that š Iām glad though crazy how a tiny tiny little crack can do that but where it was hidden under the clip it didnāt pick up the brake cleaner until really close.
Thank you everyone been a couple of stressful days but thatās a win and learn something on the way
Fuxin sweet! All you have to do now is make sure you got the right jetting for the carb! š
Have you got another rubber inlet? I can probably flog you one if needed. I went through a spell of snapping them up after I had my ācracking up problemsāā¦
I did āinjectā silicone sealant into the split and around it for a temp fix. Nothing beats a good seal thoughā¦
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Fuxin sweet! All you have to do now is make sure you got the right jetting for the carb! š
Have you got another rubber inlet? I can probably flog you one if needed. I went through a spell of snapping them up after I had my ācracking up problemsāā¦
I did āinjectā silicone sealant into the split and around it for a temp fix. Nothing beats a good seal thoughā¦
Result ay mate! Was on the phone with @HOTSHOT-III and we was running through some stuff and made me think to double check and check again everything.
Iāve just picked my spare one up from my mums so will be putting that one on tomorrow.
As regards of jetting Iāve got
4th clip on needle
240 main
.25 pilotIām sure thatās correct for my year as itās an DTRE engine.
I just wasnāt sure if I needed to upjet at all as Iāve got dep, Boyseen dual stage reeds and 1mm oversize re bore?I will do a plug chop when itās all running properly and go from there
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I feel like a right idiotā¦
So the main problem was the split in the inlet rubber got new one on. But when I was changing the jets I had a jet that came in the carb already and that 20 pilot from mikuni I put it next to a .20 pilot I had from my new jets and the new jet holes was tiny compared to this one, to get the same size holes from my new jets compared to this 20 I had would be like a 35ā¦
Never buy jets from eBay thatās a Chinese seller I guess
So anyways my mates got a dt so I rang him up and borrowed a 25 pilot and sure thing it ran the sweetest ever!! So now I need to order a 25 pilot from a good company also will probably get a 240 main jet aswell while Iām at it
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I feel like a right idiotā¦
So the main problem was the split in the inlet rubber got new one on. But when I was changing the jets I had a jet that came in the carb already and that 20 pilot from mikuni I put it next to a .20 pilot I had from my new jets and the new jet holes was tiny compared to this one, to get the same size holes from my new jets compared to this 20 I had would be like a 35ā¦
Never buy jets from eBay thatās a Chinese seller I guess
So anyways my mates got a dt so I rang him up and borrowed a 25 pilot and sure thing it ran the sweetest ever!! So now I need to order a 25 pilot from a good company also will probably get a 240 main jet aswell while Iām at it
Bud! Iāve done the fleabay SHITTY jet thing myself. Donāt beat yourself up, itās all a learning curve š ā¦
I got a good aftermarket .25 jet from
Sportaxracing. The difference it made to my bike was unbelievable. Starts first kick, ticks over and revs up crisp and clean. Itās where Iād goā¦Iāve also bought āEBCā jets that were shite, because getting a Mikuni genuine.25 is impossible in the UK. I donāt know if a genuine 240 is possible eitherā¦
Iām happy for you that itās running sweet! š
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Bud! Iāve done the fleabay SHITTY jet thing myself. Donāt beat yourself up, itās all a learning curve š ā¦
I got a good aftermarket .25 jet from
Sportaxracing. The difference it made to my bike was unbelievable. Starts first kick, ticks over and revs up crisp and clean. Itās where Iād goā¦Iāve also bought āEBCā jets that were shite, because getting a Mikuni genuine.25 is impossible in the UK. I donāt know if a genuine 240 is possible eitherā¦
Iām happy for you that itās running sweet! š
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I was annoyed but pleased at the same time I finally narrowed it down mate!
What do you think of these?
https://jetsplus.co.uk/product/mikuni-pilot-jet-vm22-210-ax100-en-tzr-tm-2-stroke-4-stroke-10-65/@OllieDTR Looks like a good website to me but TBH I've never bought a Mikuni pilot jet so I wouldn't know how to measure them to ensure they're genuine. I think there's a set of gauges you can buy which are just labelled bits of wire the correct diameter.
Mikuni main jets you can get from PJME so it might be worth calling them and asking about the pilots, also try Allens Performance in the UK or Mikunioz.com (things posted from Australia arrive surprisingly quickly).
https://mikunioz.com/?v=13b249c5dfa9
https://www.allensperformance.co.uk/
And I'd take a look at Yamaha France parts lookup, get the part numbers of the jets from a late model DTRe and then Google for these because someone somewhere might have a NOS one and if it's in a sealed bag with a Yamaha part number it's bound to be genuine.
Yamaha France is a very good resource generally; very accurate and they seem to have info for any Yamaha product, not just those sold in France and on a PC you can just hit Translate. As an experiment I keyed in the VIN number for my original 1990 white/red UK (i.e restricted to 12bhp via no YPVS servo and PV pinned closed) DTR I owned in 1992 and it showed the PV end cap on the barrel instead of the YPVS pulley, cables and servo. Obviously it made no reference to myself and several other teenage malcontents accidentaly on purpose reassembling these components by the side of the road to alter this about an hour after I bought the bike...
https://www.yamaha-motor.eu/fr/fr/service-maintenance/parts-catalogue/
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@OllieDTR Looks like a good website to me but TBH I've never bought a Mikuni pilot jet so I wouldn't know how to measure them to ensure they're genuine. I think there's a set of gauges you can buy which are just labelled bits of wire the correct diameter.
Mikuni main jets you can get from PJME so it might be worth calling them and asking about the pilots, also try Allens Performance in the UK or Mikunioz.com (things posted from Australia arrive surprisingly quickly).
https://mikunioz.com/?v=13b249c5dfa9
https://www.allensperformance.co.uk/
And I'd take a look at Yamaha France parts lookup, get the part numbers of the jets from a late model DTRe and then Google for these because someone somewhere might have a NOS one and if it's in a sealed bag with a Yamaha part number it's bound to be genuine.
Yamaha France is a very good resource generally; very accurate and they seem to have info for any Yamaha product, not just those sold in France and on a PC you can just hit Translate. As an experiment I keyed in the VIN number for my original 1990 white/red UK (i.e restricted to 12bhp via no YPVS servo and PV pinned closed) DTR I owned in 1992 and it showed the PV end cap on the barrel instead of the YPVS pulley, cables and servo. Obviously it made no reference to myself and several other teenage malcontents accidentaly on purpose reassembling these components by the side of the road to alter this about an hour after I bought the bike...
https://www.yamaha-motor.eu/fr/fr/service-maintenance/parts-catalogue/
Thank you for all that info bud if doesnāt go un missed!
So today Iām going to look at my slide to see what number it has on it, just looking at the emulsion tube needle etc itās definitely the higher jetting rather than the dtre 210, 17.5
As yesterday I tried the 20 pilot that came in the carb and had to have the airscrew right in so definitely needs upjet so I can have it 1 to 1.5 turns out so with the 17.5 the standard DTRE engine has thatāll be to low, maybe itās because itās got some āperformance modsā on to the bike bike now I donāt know, Iāve ordered from that jets place now looks like one of the better sites and got good reviews, Iāve ordered 210 main, 220 main, and 240,
22.5 pilot, 25 pilot and 27.5 pilot just incase I need to go to 27.5 not sure why I would but always good to have incase,
I paid Ā£8 before for them other jets that should ring alarm bells as I got like 20 jets for that priceš and now Iām paying Ā£5 a jet
Ready for the road soon š¤š»
I did order a horn for the bike from AliExpress and it cost me 40p with free shipping and it arrived in 8 daysš it works like a horn and canāt complain for 40p š -
Yeah, if you're going to use aftermarket jets then DON'T JET TO STANDARD! Jet to suit!
It's fine to have knock off jets, provided your entire collection is knock off.
I just buy genuine jets and stick to genuine.
240 genuine may be 210 or 260 knock off. So to say "It's stock jetting" but using aftermarket jets would leave us scratching our heads as to why it isn't working. Potentially leading us to misadvise and cost more money in the long run.
I don't have Mikunis in any of my bikes, they are all Dellortos and Eurocarb seems to have me covered on that. Dellortos were also used on the Belgarda engines as well as the Aprilia RS 125s and many Italian bikes. Common scene in the Vespa/Lambretta world and therefore abundance of parts available.
Not sure why you're having trouble with Mikunis...
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Yeah, if you're going to use aftermarket jets then DON'T JET TO STANDARD! Jet to suit!
It's fine to have knock off jets, provided your entire collection is knock off.
I just buy genuine jets and stick to genuine.
240 genuine may be 210 or 260 knock off. So to say "It's stock jetting" but using aftermarket jets would leave us scratching our heads as to why it isn't working. Potentially leading us to misadvise and cost more money in the long run.
I don't have Mikunis in any of my bikes, they are all Dellortos and Eurocarb seems to have me covered on that. Dellortos were also used on the Belgarda engines as well as the Aprilia RS 125s and many Italian bikes. Common scene in the Vespa/Lambretta world and therefore abundance of parts available.
Not sure why you're having trouble with Mikunis...
He bought the bike with the wrong jets fitted, You canāt get a .25 Mikuni genuine pilot jet in the UK for love nor money š
I got a .25 pilot from sportaxracing and i know the bikes been running sweet since. Itās unmarked but runs perfectly. I really couldnāt comment on the othersā¦
Only way to tell a genuine Mikuni jet is that they have a tiny āsquare in another squares cornerā stamped into themā¦