Honda NS125 RK problem

aviator543 · L Plate Warrior Joined: 19 Jan 2013 Karma :

I have just bought a 1989 NS125 RK and since I bought it it keeps wanting to stall at low revs, hot or cold but wouldn't if I kept the revs up. This morning it stalled 5 times, a few at low revs and a few at high revs. Each time I had to wait a few minz before it would run again and each time it would die 5 minz down the road. Does anyone know what the problem could be? I'd be greatful for any help

nightshaddow · Nearly there... Joined: 18 Feb 2008 Karma :

could be anyone of a few problems

most likely the idle is too low, turn the idle up with the screw to left side of the carb

does the bike run well while riding under load ie accelerating riding at a steady pace
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"WHAT DO YOU MEAN 100 MPH THATS IMPOSSIBLE Its chinese OFFICER."
Current rides CB 125 TDE(the next project) NS125RK ( now on the road ) CB125TDC (soon to be project 17) melody ( the nephews )

aviator543 · L Plate Warrior Joined: 19 Jan 2013 Karma :

nightshaddow · Nearly there... Joined: 18 Feb 2008 Karma :

sounds like you could have a general fuel flow problem then as it is cheap and easy to do give the poor thing a service,

change the coolant
change the spark plug
change the fuel lines and filter (or fit inline if one not already there)
clean the carb
change the engine oil

if you do it yourself it should cost you less than £20
____________________
"WHAT DO YOU MEAN 100 MPH THATS IMPOSSIBLE Its chinese OFFICER."
Current rides CB 125 TDE(the next project) NS125RK ( now on the road ) CB125TDC (soon to be project 17) melody ( the nephews )

Aff · World Chat Champion Joined: 05 May 2011 Karma :

Up to 1/4 throttle is controlled by the pilot jet.

Take the carb apart and give all the jets a good clean.

If your still having issues, check all carb rubbers for splits/cracks.

If that's fine someone may have changed your jets, if you have a pilot jet that's too large, your bike could be running rich on the pilot and that will make it feel sluggish and bog under 1/4 throttle.
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Current Bikes:Honda 929RR Fireblade, Honda CD200 Benly (Project), Stomp Z2 140
Electric Bike Project

aviator543 · L Plate Warrior Joined: 19 Jan 2013 Karma :

The idle screw was about 6 turns out so that's why it was stalling all the time, that's fixed now. Thanx for that info nightshadow and I'll service it at weekend. Aff I'll strip the carb when I'm servicing her and keep you informed. I came to the bike this morning and noticed the petrol tank was empty but I gave her 2 gallon 60 miles ago, the bike should do at least double that on 2 gallons. Is this a simptom or does my bike just drink way too much?

skatefreak · World Chat Champion Joined: 06 Feb 2010 Karma :

The NSR will get 50MPG if you are hammering it, around 75mpg if you behave so it sounds like something's not right there...

-Jvr

Aff · World Chat Champion Joined: 05 May 2011 Karma :

If its running rich it wont be doing any good to your fuel economy.
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Current Bikes:Honda 929RR Fireblade, Honda CD200 Benly (Project), Stomp Z2 140
Electric Bike Project

nightshaddow · Nearly there... Joined: 18 Feb 2008 Karma :

aviator543 · L Plate Warrior Joined: 19 Jan 2013 Karma :

Bit of an up date... I changed the 2 stroke/trans oil, the coolant and cleaned the air filter before the weather hit me today. Looked at the old spark plug and it looks like it has carbon fouling so I think it is running rich like Aff said. Couldnt get hold of a carb rebuild kit in time so can't do anything to fix it yet. I may ajust the pilot screw to see if that helps at all