Runs with choke
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Fuxin sweet! All you have to do now is make sure you got the right jetting for the carb!
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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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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Bud! Iāve done the fleabay SHITTY jet thing myself. Donāt beat yourself up, itās all a learning curve
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!
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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/
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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 price
and now Iām paying Ā£5 a jetReady for the road soon
I did order a horn for the bike from AliExpress and it cost me 40p with free shipping and it arrived in 8 days
it works like a horn and canāt complain for 40p -
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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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
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¦
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So jets arrived today put 25 pilot in and runs a lot better but still hangs for couple seconds before idles good again. Air screw all the way in so needs bigger, Iāve ordered 27.5 and 30 pilot
Strange how big it is but all bikes different I guess
Mod listBoyseen dual stage reeds with rev plate
Dep downpipe and end can -
@OllieDTR
15~16mm
The 21 is the setting for the 26mm round slide Mikuni fitted to early bikesā¦Have you fitted the 240 main? Thereās no way you should need a bigger jet than 25. Needle 1 groove up from the bottom. Airscrew 1&1/4 turns outā¦
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If it ran perfectly with your mates genuine.25 Mikuni pilot in it, itās possible that the one you bought is subpar.
Get a known good one from sportaxracing, they are perfect. Edit: I can absolutely vouch for them
ā¦It needs the proper main jet as well ā¦
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@SpookDog
Right so, the mates 25 pilot jet worked the same as my 25 pilot jet but you had to have the airbox closed off a fair bit for the revs not to hang,Iāve ordered 27.5 and 30 from sportx place so should be here today
I tested the bike with them Chinese jets I put the biggest one I had in which was 37.5 obviously itās not that big in genuine mikuni size but that worked really well with the airbox opened up almost to the size of the snorkel,
I think the 30 pilot will sort it out, I was just thinking if my airscrew is 1.5 turns out and it revs perfect does it matter Iāve got a big pilot?
The way I think of it all bikes are different so they all wonāt work on stock jetting? Iāve got 0 air leaks and few mods so can understand it running a bigger pilot?
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@OllieDTR I don't think it matters within reason what size jets you end up running as long as the actual running of the bike is good.
A lot of this kind of stuff is caused by the vagaries of mass production, it's pretty common even with competition bikes for two people to buy the same model off the showroom floor, then find out one runs better than the other when they go out riding.
In the 90s Performance Bikes magazine bought a 500 miles from new damaged repairable Kawasaki KR1-S to make into a road racing bike. It didn't run very well (they dyno'd it at 45bhp and a good one of those is more like 60) so they stripped the engine and found the KIPS valves had been fitted the wrong way round at the factory and some of the port timings were over 1mm out. IIRC they got it blueprinted (which just makes every dimension in the engine exactly what it should be) by Stan Stephens and without any actual tuning this resulted in almost the exact power output Kawasaki claimed when they tested it again. It ended up being faster than some of the "tuned" ones they raced it against!
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What does āhave the air box closed off a fair bitā mean? It works ok?ā¦
Try to post a video, or get someone on the phone to hear the ārevs hangā just to see how much of an issue it is. Are you trying to fix a fault or balance your ātuning mods?ā¦
Put things back to standard to fix faults. Then when they are fixed go ahead with tuning, or modding. Otherwise itāll just exasperate the problemā¦
