NSR dies when throttle twisted

[Fidge]

I have bought an NSR 125 (JC20) but when it starts the engine will die Id i leave it idle for 30 secs, If i twist the throttle when it's started it then dies. What is the problem and how do I fix? thanks

(The bike barely been used for the past 6 years or sow and been sat around).

[Vincent]

Sounds like crap in the fuel and possible blocked jets in the carb.
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[Fidge]

Thanks, could you tell me how to fix or what to search for on the internetwork?

[Vincent]

you could try searching on here for "blocked jets" or similar.

Have you taken any old fuel out of the tank?
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[RhynoCZ]

Could be dirt or it could be water in the fuel. Take the carburetor off and take off the carburetor's bowl. If there is a ball of slime, you have water in your fuel. If nothing, then give it just a proper clean. Get it all back together and ride it. You don't even need to take it all apart, just the bowl and the float. Spray some carb-cleaner into jets, blow all the dirt out.

If this won't help, the ignition could be faulty.
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'87 Honda XBR 500, '96 Kawasaki ZX7R P1, '90 Honda CB-1, '88 Kawasaki GPz550, MZ 150 ETZ
'95 Mercedes-Benz w202 C200 CGI, '98 Mercedes-Benz w210 E200 Kompressor

[Fidge]

[Vincent]

Aye....get all the old fuel out. You can syphon most, then remove the tank and get every last drop out.

Might be a good idea to get yerself a workshop manual.
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[Fidge]

[Fidge]

Do you know how to use these clips? how do I remove and put back on? https://i.gyazo.com/3b4be4e8b0f1d94a3abb2a0ee2523513.png

[Vincent]

You should be able to twist them and get them off. they're not the best type and can deform once removed.
Try and twist the pipe and pull at the same time.
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[Fidge]

ahh, been working on the bike all day and now I've put the hard bits together there is a petrol leak in the carb. I think it's because there weren't any O rings or they need replacing and I couldn't see a strainer screen in there https://i.gyazo.com/2a3a8e42e8f7087e7d0a9dcb4e77087f.png

[alains]

carb is 28PHBH/** (** FD for JC22 , FS for JC20)
see spares https://www.dellorto.co.uk
strainer is 6109,banjo is 6273A,Oring is 9424 (i hope you've got the bolt)
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[Fidge]

Do I need to use a spark plug removal tool to remove the spark plug or can I use a spanner because I don't know how I would get one of those long tools in here.
https://i.imgur.com/pyEHHni.jpg

and where do I measure a fuel filter from?
https://i.imgur.com/RXmFTBo.jpg

thanks


Also do any of you know if there could be anything else causing the leak? the carb seems to have a lot of petrol in it when removing, could there be a float problem and petrol coming out the overflows or faulty overflow screws (if they exist)?

[alains]

normally the tool is given with the bike
if you havent buy a tube tool (short) with a rod
any motoring shop will have it
something like this
https://www.ebay.co.uk/itm/Spark-Plug-Removal-Tool-Trials-Bike-Beta-Evo-Rev-3-Gas-Gas-Scorpa-Sherco-4rt-/111467393216?pt=UK_Motorcycle_Parts&hash=item19f3f970c0
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the worst day fishing is better than the best day working

[Fidge]

[alains]

NO!!!!!!!!!!
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the worst day fishing is better than the best day working

[Vincent]

Whilst you're always better off using the right tools, I can't see any problem using a spanner to get the plug out, just be careful not to damage the ceramic part. Some old British bikes had normal type spanners for the plugs in the tool kit.

Looks like you need an ew plug cap too
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[Fidge]

I have a new problem, the fuel leak is coming out the overflows, apparently its because of blocked passageways in the carb, is there any other reason everything could be overflowing? The overflow screw is done up and float seems to be working correctly.

[Vincent]

Did you replace the float valve?
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[Fidge]

[Vincent]

If it's got a rubber tip on the needle, it may have gone hard. Did you say the bike's been standing for a while?
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[Fidge]

[Vincent]

You'll probably need at least a new float needle. That's the problem with getting a bike that's been standing - various different seals can petrify and start to leak. Let's hope the crank seals are ok.

Be aware that if the carb overflow doesn't work for any reason and the float is sticking open, the fuel may get into the cylinder which can cause all sorts of problems.
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[Fidge]

This thing inside the float chamber being the float needle? What does it do?
https://i.gyazo.com/953b0040248bba47b9e5e8b31c4a9721.png

[alains]

just dismantle the carb and clean it , especially the float valve !!!
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the worst day fishing is better than the best day working