1994 Yamaha Dt 125 RE Carb Replacement Advise
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Hi guys, I'm a complete newbie to motorbike world and get started riding one by owning a 1994 Dt 125RE which i've been using for a month. I like the bike very much but have some issues with my carburetor (i guess) which leaks fuel all the time (also all the fuel time to time) and causes bogging when i throttle a bit especially while the engine is cold. Anyway, i headed to a couple of repairmen but all complained about the bike and didn't show any interest in looking into it and repair accordingly. So eventually i decided to buy a fresh new carburetor and replace the current one to able to get rid of these issues mentioned.
When i look into specs of the bike on the internet it tells me that this bike uses a Mikuni branded carburetor called TS28SS https://www.autoevolution.com/moto/yamaha-dt-125-r-1993.html#aeng_yamaha-dt-125-r-1993-124 But despite my searched there's nothing about that carburetor on the internet and the closest model i could able to find is Mikuni TM28 carburetor. I kindly need your help guys on which carburetor model is the best fit for my bike. There are also so many knockoff choices out there on Aliexpress so i kinda a bit confused where to go.
Any advise and help would be appreciated very much.
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You have the original carb, they are pricy cause theyre the best fit for the DT. I wouldnt change it for a chineese copy. Go to ebay and buy a bowl gasket, needle valve, replace a hose that goes from bottom cover to the power jet as it should be black, made for constat fuel flow. The transparent ones are not so good. Clean the carb, blow all the lines and jets with compressed air. Maybe rejet it with 240/30 jets depending on your mods/exhaust system and set the air/fuel ratio at the end. I bet there are some guides on the internet on how to do that in a 2 stroke. Just handle the air mixture screw with care, yours looks good and you dont want to mess it up as it can be costly to take it out later. Where does it leak from? Maybe the fuel hose from the tank does not sit tight, or the fuel tap needs to be rebuild?
You can also unplug the carb heating system(two hoses that go from the head to carb).
Generally there are many things to consider when setting up the carb as the needle position, jets, idle rpm screw and air/fuel mixture screw. You will have an easier job with this one as the bike runs and you can go back to the previous setting than with a new carb where youd have to find out the best setting for all of them. -
Dear @Challenger
Thank you for your reply, very much appreciated. Actually this morning i've seen the leakage was from the drainage hose located under the carb, it was heavily draining even i could able to see the fuel flow there.
Actually one of those repairmen disassembled the carb but told me that this carb is not rescuable and advised me that he can change it with another kind of (somewhat irrelevant) carb but since the guy's talk was totally cheap, i haven't been convinced by his shitty advise. My perception was that guy didn't know what is doing and gonna fuck up my bike. The rest of the repairmen i headed even did not show any interest and blackmailed yamaha dtr models by claiming that there's no permanent solution for such leakages, they even advised me to sell the bike.
I mean, the thing is that there's no any well proficient an reliable repaiman around so eventually i come up with the solution of replacing the carburetor completely with a new one which might be a best fit. If i go for rebuilding the carb by myself i'm sure i'm gonna mess it up.
Your advise is very valuable, please let me know.
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@dtre94
Sounds like the Float level is Setup all wrong,Motorcycle carbs are very simple when you get into them, if you plan on riding a 2stroke, then learning about carburettors by rebuilding the one you have, which is probably fine is the best thing to do,
You will need a Haynes Manual for the DTR/RE, this will be the best resource for you to rebuild it, and learn more!
It’s easy, basic tools, we can help you with carb setup at least here on the forum,
Don't buy just any carb, you will find it difficult to even fit one in there, let alone set it up,
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@dtre94 then if it comes to the leakage its either float level valve(called it a needle valve in earlier post, sorry) or someone bent that little blade on the float that closes the valve so it now overfills or the drain screw not tightened or damaged.
I cant help you much with choosing a new carb, if you buy one of these:
https://www.ebay.com/itm/MIKUNI-FLATSLIDE-CARB-MIKUNI-28MM-VM28-418-28-mm-42-6090-13-5047-VM28-418-TM28FS/331172516361?epid=171186446&hash=item4d1b6b9209:g:wE8AAOSwhiZaUKEs
then you'll have to switch the top cap(where you mount the gas cable) as here it goes straight up and you need it to be bent about 60 degrees as it is now in your carb.
This carb is higher in general, dont remember if theres space for it in the DT. And the new ebay ones are generally in worse quality than the original one from the DT. They also use older type of floats, from the '70s-'80s. I wouldnt buy this one.
If you buy something with round slide there will be some loss on the performance.I heard some guys saying positive stuff about PWK carbs but im totally not familiar with them. But its the same thing with them, the gas linkage mount goes straight up and you wont switch your current top cap to them.
At the end its your choice. I learned all about those bikes myself, and for me its a big part of fun, not only riding but maintaining them.
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Dear @Challenger and @Darty
Thank you very much for your advise. I understand that there's no drop in replacement for this carb which will perform like the original. There are repair kits for the the stock carb on the internet like the ones below:
Rebuilding my carb by using this kit, is that possible to fix the leakage and resume a proper response when throttling?
Thank you.
