ns125rk , poor running

[stubydoo]

hi there every one. im new to this so please be patient with me. i have a ns125rk on a 89 plate. im having problems getting it to run properly. it has an allspeed exhaust. and up to about 6000 revs it is very rough. it splutters as though it is missing and runs very unevenly. once passed 6000-6500 it starts to pull very well and by 7500 starts to realy fly, all the way up to 10500 ish revs . have tried different jets in the carb. it had 48 slow jet,95 power jet and 170 main jet. it now has 42 slow jet, 65 power jet and 138 main jet. have tried mixing and matching the jets but cant get it to run properly at low revs. have also just put new rings on the piston as compresion was down to about 103 psi . any help on this would be greatly recieved. many thanks, stuart......... also if any one wants to they can contact me on the phone . 07894749606. cheeers .

[Kickstart]

Hi

Firstly those jet sizes sound far too large. Certainly the 170. From the Honda workshop manual the main jet is listed as a 110 (and this is covering the full power version with a 48 slow jet.

Secondly the main jet is there for fueling at or close to full throttle. It acts as the ultimate limit on fuel. At mid revs you should be on part throttle and that will depend on the needle position. Standard it should be on the 2nd groove.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[stubydoo]

thanks for that . is that the 2nd grove down on the needle?

[Kickstart]

Hi

Yep, 2nd from the top in the manual.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing