Derestricting a DT125RN (4BL, 1997) Looking for advice before I buy

[panosm00]

Hi all,

I'm looking to buy a Yamaha DT125R and I've found one, but it's a DT125RN, model code 4BL, from 1997. I've heard this version is restricted to 80 km/h.

Does anyone here know how to derestrict this specific version? What exactly is limited on the 4BL (exhaust, carb/jetting, ignition/CDI, power valve, intake), and what needs to change to remove the restriction?

Also:

• Which parts are needed, and are the originals still available?
• Any problems to watch for after derestricting (jetting, reliability, piston/cylinder)?
• What should I check before buying the bike ?

Photos of what to look for would be a big help. Thanks in advance!

[Calum]

Lot's of information on this site already.

I find going to Google and use site:dt125r.co.uk 4bl derestriction better than the internal search.

https://dt125r.co.uk/topic/3102/derestrict-yamaha-dt-125-r-1997/66?page=4

It does depend on what region you live in, but the easiest way to get full power is

• Zeeltronic Ignition
• DEP Pipe

Make sure you've got 3MB cylinder head (3BN denotes you've got a combustion ring head that benefits from machining out). But otherwise you'll be laughing!

[panosm00]

@Calum yea the thing is that I have heard that the German version uses a diffrent cdi from other regions and I haven't found a guide on how to derestrict the cdi on a German one