DT125R FORUM

Use Yamabond to seal the crankcase halves.

https://www.ebay.co.uk/itm/283564713529?chn=ps&_ul=GB&google_free_listing_action=view_item

Like that bud

Why would it be the waterpump? That's on the other side of the engine/bike. It's no where near the stand?

Do you mean you think it's getting hot and overflowing because the waterpump doesn't work???

The Mikuni 28mm that is fitted from factory is a very good and serviceable unit. Before replacing it, it is well worth giving it a refurbishment first. They're also becoming like hens teeth and as such is well worth keeping ahold of.

I ended up going with a 32mm Dellorto VHSA that's found on the same engine which is fitted to the TZR Belgarda.

Sometimes you can hear the little end rattle, if it's never been replaced then that can cause some noise.

Another one can be the right hand side powervalve has come loose. Can whip the cover off and make sure it's all secure.

Be careful removing the cover though as they have a tendency to crack off.

@Stevie-Wonder Yay! Congrats dude! Welcome to the big boy club!

Aww, that sounds sick. I live near the Forest of Dean which I imagine would be endless fun of cycling round there. But I've never been as I don't have anyway to transport push bikes over to there (40 ish mile).

That does sound like hard work though, just keeping the bikes riding nicely

@gary76 I have logged into it myself with no dramas with the credentials provided in the email (omit the quotes).

You can confirm this by looking at the Last online date: https://dt125r.co.uk/user/gazza76

Oh yeah that's smart that.

Do you get much time to go out on them?

Yeah fair play! That's a sweet build there.

As much as I love the DT and motorbikes, there is something so satisfying about a quality push bike. It's such an efficient mode of transport.

I clear/delete accounts that have zero posts/rep and inactive.

But otherwise you probably just forgot your password. I can reset the password for you to the associated email address.

I've never had any luck with the Chinese ones winner racing. I say that but the ones I bought for my ETX were from them and they actually fit, sort of.

But I have bought numerous previous one to no avail.

It's looking smart with that pipe on it.

The usual suspect for running hot can be the thermostat.

I must admit, DTs always seem to run hot, I tried all sorts (including twin radiators) and the solution for me was to remove the thermostat.

This is really not ideal as the thermostat is an integral part of the engines cooling, it applies pressure to the cylinder head and prevents hot spots from forming.

But I found the DT was just running too hot and would benefit from a lower temperature thermostat (especially if tuned).

But as they say Mr Yamaha know what they're doing and it's a tried and tested machine

Oh hey blast from the past!

Yeah @HOTSHOT-III is still knocking about.

Sorry to hear about your health problems, considering how much you use your DT that's a crying shame.

Good, sounds like you've ruled out those two main issues, so it'll be something simple. Radiator cap is a usual suspect.

Okay, good, using a good gasket set and the head/skim means it's unlikely to be that.

But yes, the headgasket only goes on one way.

You should be able to read UP on the gasket as it's installed. Otherwise you've installed it upside down.

Let's assume you haven't done that and it's all installed correctly, then I'd still be looking at the overflow bottle. It's possible that your radiator cap is shot and it's not hold 1.3 bar of pressure anymore and just overflowing.

The kickstand, or are you talking about the coolant overflow pipes that should be routed through the holders next to the shock absorber to the flow.

This is usually an indication of head gasket failure.

When you rebuilt the top end, did you skim the head like I describe: https://dt125r.co.uk/topic/11/how-to-i-gentle-skim-your-head-barrel

Did you ensure to use genuine/Athena head gasket?

Do not use those cheap white head gaskets they don't work.

Also did you fit the gasket the right way around.

If you stick your fingers into the top of the radiator, are your fingers black/oily?

Okay...so some overnight parts from Japan and CMSNL and some others from Australia I've finished the gearbox rebuild.....

Brand new genuine output shaft from Japan and a brand new genuine 3rd gear....

This completes the output shaft rebuild.

New genuine shims, circlips and bearings.

Fingers cross that's all back together correctly, I'll have to remember to select all gears and test BEFORE firing up the motor, else this will be £8000 down the drain if it destroys the motor.

And whilst picking the shock spring up from the paints for my ETX, I also picked up the swinging arm for this bike too.

Should go without saying, all near bearings and a lovely carbon fibre chain guard which I bought about 5 years ago for the Raptor. I'll probably keep the Raptor bone stock and therefore it's not needed for that project and can go onto this beasty.

I did have some swinging arm spool spacers machined up but for the life of me I simply cannot find what I done with them. No doubt they'll turn up eventually.

@HOTSHOT-III No, I believe it's a Yamaha DT230 Lanza arm. But yes it's like half the weight of the original one I had. I just need to get the right parts machined up to fit my wheels etc. I've been so spent on 4/5 other very expensive projects that I just haven't bit the bullet yet to order the machine shop work.

With regards to mudflap where, I'll probably design some sacrificial item in CAD and 3D print it.

@RikuRo I've sent you various links. Any DTR from 1989-2004 will do.

https://dt125r.co.uk/topic/13/kick-start-conversion-dtre