ns125r-k help please?

greenwood2000 · L Plate Warrior Joined: 13 May 2021 Karma :

So i've got an ns125r-k 1989 model.
When i bought it the guy listed a few jobs left to finish, and he doesn't think it was jetted properly. Can anyone tell me what all the stock jets are, and where to find em? I can't seem to find a website that makes it easy to pick the jets out.

It's got a huge flat spot starting at about 6krpm, which just totally kills the power. If there's anything else to check/possible causes that'd be great as well. Running the stock airbox and exhaust at the moment so i presume the jetting just needs fixing?

Cheers.

MarJay · But it's British! Joined: 15 Sep 2003 Karma :

You sir are the jammiest man who ever lived.

You come onto a forum which originated not as an NS125 forum, but as an NSR forum.

You find a man whose first bike was identical to your bike.

Who bought a Haynes manual back in the day

who retained said Haynes manual

Who recently retrieved it from his parents loft, not deliberately but in a box of junk his parents wanted rid of

Who then placed said Haynes manual in his library of Haynes manuals instead of getting rid

Said library is easy access from where said man currently sits

The man had the inclination to walk down to the garage to retrieve said Haynes manual and take a photo of the correct page.

https://www.bikechatforums.com/files/ns125r_carb_spec_small.jpg
____________________
British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

greenwood2000 · L Plate Warrior Joined: 13 May 2021 Karma :

Brilliant!
Cheers mate

bit of a question though. It says main and slow jet sizes, but what do i need for the rest of em? there's a power jet and starter jet, and a needle jet too i believe?

thanks for your help

MarJay · But it's British! Joined: 15 Sep 2003 Karma :

Nobby the Bastard · Harley Gaydar Joined: 16 Aug 2013 Karma :

MarJay · But it's British! Joined: 15 Sep 2003 Karma :

greenwood2000 · L Plate Warrior Joined: 13 May 2021 Karma :

cheers lads that's great. I'll get it all back to stock and let you know how it goes

Robby · Dirty Old Man Joined: 16 May 2002 Karma :

I had one of them.

Check the rear shock linkage. They tended to wear and develop a lot of play 20 years ago, so will probably need their second rebuild by now.

Possibly a pain in the arse to de-restrict the exhaust. Conventional wisdom used to be to buy an aftermarket one, but it may be possible to DIY it now. Tools like welders were expensive back then and commonplace now. If you're lucky it just needs to have a washer drilled out in the collar.

stevo123 · Nitrous Nuisance Joined: 10 Aug 2004 Karma :

Can confirm, washer in downpipe section of exhaust and restrictor plate between carb and reeds. Also check exhaust port is clean - a lot of years ago when I had my exhaust off to get the restrictor out the port was really furred up. Probably caused by previous owner using shit 2T oil made for chainsaws or something not as fussy.