Airsick

Since I'm rather new, How do I adjust the main jet ? And which plugs am I checking and for what color ? Also I'm unfamiliar with the term leaned her out on w open throttle. And what would I check for an airleak? Thanks for your input and sorry for being such a newby that doesn't know much yet.

Hey I just wanted to give an update about this. So I took my bike out for the weekend 8-17. Well after playing around with my clutch things were working and I was making the best of it. Well after about 40 miles of riding it just takes a dive on me. Turns out I blew the piston and I was mis diagnosing the clutch for bad compression. Well I still think that my clutch will need adjusted but that's where I am. Currently in the Process of getting it replaced. Thanks for the input.

That term sounded familiar but I had to google it. I will be honest I'm just getting into how to actually work on my own bikes. So after learning what the term is, I would have to say yes. I have experienced clutch slipping. I can't say that this has happens all of the time but I have noticed times where the rpms spike and I have no surge in road movement or anything - so long as I understand the term. I have not adjusted the cable. If the clutch mechanism is the bolt that engages and disengages in the crank case when the clutch is pulled then, yes I have started making adjustments to that. I've made adjustments that make it feel like the gears are grabbing and everything, but I don't know exactly what I'm looking for when adjusting it. I put a couple of marks on the bolt to see if it was changing position after I made adjustments. I hope I've been able to describe this well, and thanks nayruf for that comment.

As an update. I thought that I may be having a fuel issue, my bike has been out in the hot weather for the 6 weeks or so and not I wasn't ridding much since I needed to change my front tire, and I hadn't ridden much. Tire replaced, and then I drained the fuel tank, replaced my inline fuel filter and replaced the fuel line as well with higher quality fuel line. It's running a lot better, I'm still having a slight power issue, but more within the gears itself rather than the engine- if that makes sense. So what happens is that when I'm in gear and start reaching higher rpms 5-6K it acts like it doesn't have a lot of power in the gear, the engine sounds good but you don't really accelerate that much when romping on the throttle, when you shift up to a higher gear, then you can accelerate some more until the same thing happens with the higher rpms. I would say that in 4th gear I was going about 35 or or so. I'm wondering if it's something to do with the clutch or transmission but not sure how to even go about testing. Thanks for reading.

Hey everyone, how's it going? I recently picked up a 79 XS400 and had been riding that around. I finally came back to my DT125 for a camping/motorcycle trip this weekend. I'm starting to loose power when you get to about 4-1/2K to 5K rpms after the bike has been running a little and starts to warm up. I say power loss but it almost acts like it's not quite getting the fuel that it needs. Also along with this is that it has a harder time starting up when it warms up and is experiencing this problem. I'm not sure if this could be a vapor lock issue - not very familiar with that. Any help or advice would be appreciated. Thanks.

I probably shouldn't post this on this link, but since people have mentioned a knocking sound and a loss of power, I figured it may not hurt. I'm starting to experience a power loss around 5-6000 rpms and I occasionly hear some knocking sounds. I may have seen blue smoke a couple of times when I've fired it up, but I can't say that I've consistantly seen blue smoke at all. This is for a 74 DT125a. Thanks alot. I'd appreciate to know if it's bad etiquite to ask a question like this on someone elses question. Thanks.

Hello everyone, My name is Josh. I'm from Pocatello, Idaho. I've just recently gotten into fixing up older motorcycles and I've really been enjoying it. Right now I'm currently working on a 1974 Yamaha DT125A and then I have a 1974 and 1979 Suzuki 185 TS that are in the process as well. I look forward to seeing everyones future, and current projects and being a member of this group. Thanks a bunch.

Hi everyone, I have a couple of problems and I'm going to do my best to describe them. As the title indiciates I have a 1974 DT125A I'm pretty sure it's the DT125A from research that I've done, and some references I've seen linked on other posts. First Issue: head light and tail light and brake light does not work while it is running. I've found the flasher relay and when made some slight adjustments on the outside - part of the assembly will spin somewhat - probably not a good sign. When it is rotated sometimes the lights will work while it's running. I suspect that the relay needs to be replaced but was wondering if anyone has had a similar issue or offer any other suggestions on how to repair/fix it without replacing. Second issue: Along with the first issue, sometimes when the lights are turned on and the turn signals are being used the engine will bog down somewhat, there have been some issues that the electrical drain will kill the engine. Not sure what this is - my only idea is the voltage regulator assembly which I've tried to clean up the best I can but I've been attempting to avoid 220$(USD) to replace it. Lastly: I've gotten to the point that if the bike is cool, or hasn't been ridden for a couple of hours it will fire right up, but now I've noticided kind of a cranking/rattling sound when it gets reved up-not sure if it doesn't have enough oil or something else- the other thing about this is that after it runs for a while and gets hot it seems to not fire the way it's supposed to or perhaps it's not getting the fuel it needs because it seems to have less power when you start reving past 4-5000 rpms - which of course is the opposite that you would expect. I hope I've been able to word this the best that I can. Thanks a bunch. -Josh