DT125R FORUM

Thank you very mutch, i will be looking for one of the Athena ones. I have managed to get hold of a 3bm head but it is badly damaged on the inside so i will send it back and switch it for a Athena head.

@Calum i have found a 3mb head, would you know the squish for this head?

Also do you know someone who could get that 3bn head ristriction out?

Ok, i will look into rebuilding the top end. I will also check the squish, do you know what the normal squish is on these bikes? Also, it got the 3bn head could that be a problem for the compression?

It gets about 90 psi compression with throttle fully open

I looked for the reed switch behind the speedo but there was none. I can attach a picture to be shure. I have a compression tester, and i will test today and let you know. I also orderd a zeeltronic cdi unit So hopefully that resolves the problem.

Hello, i have a dt125r out of 1996. I have it for several months now. And have road it for about 2 months now. Before i began riding it, i fully deristricted it. I followed the guide on this forum. I got a different pipe from romeu henriques, looked if there was a reed switch or a grey box. Nether of those where on the bike, so it probably is the CDI that is still restricted. But my problem is that it has almost no power it goes max 97 km/h ( 60 mp/h) it hits the power band at around 7/8000 rpm. But the powerband is not incredible fast, it just goes a tiny bit faster. Also it cannot rev higher then 9/10 rpm and in the last to second last gear it does not surpass 5000 rpms. I thought maybe it is the powervalve, but it moves when i turn it on. And also when i feel with my hand it is flush with the exhaust port walls. I tried disconnecting the servo and riding it with the power valve pinned open, then it had no power overall. It was almost unrideble, i tried pinning it in the closed position thats when it gave alot more botten end power. But overall still not great. What could it be that i am missing?

Ok, thank you very much for the help. I am going to try some things. And pressing out the steering stem is a good idea, because the dt stem is 30 and the Husqvarna 25 so i can just mill the 30 mm stem to 25 and press it in. Thank alot.

yes I know, but those cups are exspensive to make and I was wandering if I can just buy a bearing that fits. so do you know the size of the lower headstock bearing? because the machine shops in my area all say around a 100 € per cup for those tolerantes.

Or is there an easier solution for this?

Hello,
I am doing a USD conversion on my Yamaha DT125R 1998, with a Husqvarna 450 fork. The triple clamp axle is 25 mm, whereas the original DT125R triple clamp axle is 30 mm. I want to buy a new roller taper bearing for the underside of the headstock. When I measured it, I got 30x56x17. So, I looked for a bearing in the size 25x56x17, but there are none available. I then searched for the original taper bearing for the DT125R headstock, and I can only find taper bearings sized 30x55x17. Did I measure it wrong, or is my headstock somehow special?