DJYAM

I am not arguing anything. I am simply responding to suggestions that I have already confirmed are not issues. No need to be sarcastic. It's been suggested about cleaning jets multiple times, which I have done. Checking for leaks, which I have done. All mentioned in the original post. I have asked multiple questions regarding float height etc with no direct response, just more nonsense. Answers about 2T and jet kits aren't helpful for obvious reasons. The ONLY thing I can think that is suspect, is there is a carb balancing 'port' on the engine side of the carb, which to my knowledge needs to be sealed, and is. With a fuel line and some glue, 100% sealed. I am not aware of any other 'air bleeds' that need to be open/closed. I do understand the physics of a carb, I have spent a long time making adjustments to them in the past. The questions I've asked about being too rich, but only running in this state haven't been answered. Howcome it runs relatively well when rich, but not at a 'normal' mixture? This doesn't suggest that there is a fuel blockage.

It's definitely clean, I have been through it multiple times. This still doesn't explain the rich running, as surely if a jet was blocked, it would run ok with slightly bigger jets, to get the same amount of fuel, not huge jets.

The idle jet is now 55, and the main 140. This is running way too rich, but seems to run better with less bog. So why can't I reduce bog with smaller jets, seeing as it is now running rich? Changing needle height didn't seem to have much of an effect at all. Float height? I've tried a few different ranges and not much difference noticed.

Yes... As I said, tried multiple sizes of each jet, all clean.

So... I tried a much smaller main jet, no better. So the next step was a much bigger idle jet, bogging was reduced by a good amount! Still slightly bogging, but much better. The problem now is, the bike is running way to rich, white exhaust smoke, excess fuel in carb-engine manifold, black plug. So what now, because reducing jets just seems to create bog? Is the carb just not suited to the bike?

It's not 2T. I have a bunch of jets already, just not below 100 as stated. I assume a 100 jet in one carb would provide a different mixture to the same jet in another, due to air flow and carb design?

Can anybody advise on jet sizes? All kits seem to start at 100 for the main, does going smaller than that seem like an odd thing to do? Could the carb just be too big for the bike?

I've checked for for air leaks, all ok. Slide keihin carb. Any place to get jets that isn't China? Delivery is shocking at the moment! New ISH plug. Previous owner was that silly bugger unfortunately, hence why the carb isn't standard

Also, the bike seems to have a rev hangup. If I raise the revs, they take a long time to fall back to idle.

Hi all, Thanks for the help previously, much appreciated. I have recently acquired a Yam TW125 for some green-lane fun. Bike starts fine and seems to idle OK too. When building revs very slowly the bike seems to reach max with no issue. When opening the throttle fast the bike bogs down and dies, unless I let off immediately. The plug was quite sooty, I thought it must be too rich. All of my research however tells me that my symptoms are that of a lean bike and I should adjust float hight. I have been experimenting swapping multiple sizes of pilot and main jet. Just swapped to a larger main, 120, and noticed fuel coming from exhaust, must be too rich. The base main jet I started with was 100, now I want to reduce to 90 ish, does this sound small? I know it is dependent on airflow but standard jets all seem to be 100+? The air flow on the bike should be good as it has an aftermarket exhaust and filter. Ps. Float height has been adjusted in both directions, neither seem to help, and definitely do not cure the issue. So, does bogging sound like a rich bikes problem? Is sub 100 main jet size small? Anything I'm missing? Thanks in advance

Sorry for so many messages. I have found an exhaust that has the 2A6 code instead of 2A8. Says it's from a 125 or 175 mx. Is this the same exhaust? Not sure what the number means. Mine has 'YAMAHA 2A8-14610' This one has '2A6-14610' No YAMAHA print. Looks genuine though. (old and dented/used)

I did consider taking it to a welder, I thought by the time they had done, it may cost as much as buying one. The crack goes all the way round the tube. Maybe I should buy one for now, as I shouldn't ride it like that. And see if someone could repair it for a spare or to sell.

Haha! I think I have, haven't I! I assume these are just prone to rusting and breaking in these places, due to it being a U bend and the shaking stress. Wow, that looks to be solid. I found one for 300£ yesterday but wanted to ask in case I was about to pay way too much. Hmm, 175 any more findable? I suppose not if there the same. Thanks guys

Hi guys, I have just finished restoring my DT125MX and it looked lovely. Rode lovely. Yesterday I started it and noticed that it was much louder, sounded like the exhaust blowing. I unwrapped the exhaust tape to unveil a gaping crack round the exhaust where it drops and bends out of the engine. I have been looking for exhausts online and have seen a few. Front ends! Is the 125 the same as the 175? Or is someone looking to get rid of one? Or know who is? Cheers. Dan.

Yeah, I had noticed that the panels are a slightly different shape! I also ordered a new pair which have a hole in the side, looks like it is meant for a fuel tap? Unused on my bike! Do you know anywhere I can buy the US stickers or should I buy the UK ones? Thanks for the help.

I have just resprayed my DT125MX and am looking to replace the stickers that were on the tank and side panels before the new paint job. I have attached a photo of the previous stickers (believed to be original). As I look on images, I see that all DT125MXs seem to have different stickers to mine. Mine is a US import and was wondering if anyone could shed any light on what the stickers should be and where I may be able to purchase some. Thanks for all the help Dan

Hi Cynic, Plug is a tan/black dusty colour. I'll open the carb again and try a new pilot jet as the one I have is knackered. I'll also give the floats a good look at.

The airbox is all original, Just the stocking which obviously isn't haha! I have ordered a new filter and see if I get any results. Thanks

Do you think that'd solve the power issue? If so I'll order one now! Hahah. Have you any experience of these carbs that are sold on the web?

Hi guys, My DT 125 MX has been running well with very few problems apart from it dying when accelerating quickly. The bike runs well but when you pin the accelerator open fast, the bike feels like it doesn't want to go any faster, and the revs drop 'bogs down'. I took the carb off and cleaned all the jets, put it back on and still have the same problem. The clean helped slightly but not much. At the moment, the air filter is a stocking which isn't ideal, when I remove the air filter the bike dyes much more, even at slower speeds. I tried putting some thicker foam over the intake to in theory 'increase pressure' thinking this might solve the problem as seen as I already cleaned the carb. This made the bike way underpowered and it wouldn't pull off. I've seen you can buy cheap replacement carbs of the Internet for the DT but wasn't sure if they'd be any good. Since cleaning the carb, the bike started as usual for around half a week. Forthe the past few days, the bike didn't want to start, it did nothing when being kicked. Then all of a sudden of the 10th or so kick it would start, when the bike had been used for a little while and sat again for an hour or so it would start first or second kick. Just when it had sat overnight and throughout the day it wouldn't start. This sounded like a faulty kill switch but I don't think it can be. Since it doesn't want to start, the bike starts second kick rather than like it did previously on the first kick There re is a tiny minute hole on the front end of the exhaust that does let out some air, could this cause such a big decrease in power? Any advise you have is much appreciated. Should I buy a carb? Should I buy new jets? Should I buy a proper foam filter or will this have the same affect as before? Is there something else I'm missing? ps. I can't find any leaks in gaskets that might cause loss of pressure. Thanks for all Dan

Haha! You load of boring sods! I'm sure it will be renamed when something goes wrong. For now, nut buster.

Hi, Wasn't really sure where to post this but here goes. I just got my DT 125 MX through its MOT and was wondering if anyone had any name suggestions, it's silver. Only characteristic I've noticed so far is that it wrecks my nuts every time I sit on it. Thanks

Haha yeah, not ridden it on the road yet so haven't got used to it. Hoping to MOT it this week, then there will be another DT on the road! The headlight was a bad connection from the alternator. All up and ready to go. I am missing the side pannels, that wouldn't affect the MOT would it? Thanks for all guys

Yeah, thanks Cynic. I think I got the oil light thing into my head! Haaha.

Haha sounds about right! The headlight is about as good as a candle behind frosted glass! Will check for a dry joint etc. Tomorrow Cheers lads