nsr newbie help needed

dmatthias77 · L Plate Warrior Joined: 13 Aug 2010 Karma :

HELP NEEDED:
I just bought an nsr 2002 plate. Rode it 30 miles home, rode just as it should.

It has an induction filter on it, filthy it was so I took it off and cleaned it. Put it back on( done this several times with a car so know what im doing )

Thing is since then it wont accelerate properly, it seems to hit a wall and then splutter a bit then is fine again, it doesnt do this all the time. I just put a brand new iridium spark plug in it as this seemed the obvious diagnosis.

No change, im no mechanic. Ive tried taking the filter back off and then on again, still no change..

Does anyone have any ideas what it might be?

Kind REgards

taz4626 · Renault 5 Driver Joined: 30 Aug 2009 Karma :

at what revs does it start to splutter? and is it at the same revs every time?

slyrob · Traffic Copper Joined: 03 Jan 2010 Karma :

worth checking the powervalve servo is moving freely and not sticking, i also had a similar problem with an nsr and it was the choke cable sticking so give that a look too, failing that clean out the carbs and checking its not just rubbish in the fuel tank
____________________
Pitslayer wrote "it could be Ndubz.....ruining this once great place with donkey gobbling loafer knobbing "music".
silky666 wrote "In my eyes, when you shake cocks with the devil, you may as well go for the full reach around"
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dmatthias77 · L Plate Warrior Joined: 13 Aug 2010 Karma :

hi guys thanx for advice, with regards to revs its about 6000rpm and it does seem to be in the same place every time.

where if i may ask is the power valave, is it easy to get too. How ill I know if the choke is sticking, and how do |I stop it.

sorry for all the qs but I am NOT mechanicaly minded.

huge thanx for all advice given Smile

taz4626 · Renault 5 Driver Joined: 30 Aug 2009 Karma :

ok power valve should change at about 7k so it may be that its not changinging smoothly.

when you fist turn the key on you should hear a servo move which is your power valve resetting for starting the bike after it starts it moves again and then changes back at 7k. it is located under the tank just rear of the 2 stroke bottle (the servo part anyways) and looks like a wheel with two cables attatched to it, leave the tank up and start the bike making sure it moves once started, rev it up past 7k and see if it operates smoothly ps make sure you let the bike warm up first

this wheel and cables operates a gate as it were to allow more or less exhaust gasses out of the cylinder there is also a window on the side of the barrel covered with a small triangular piece of plastic which swings out of the way. and there are some alignment marks that need to match aswell but cant 100% remember which way round its meant to align however it is all in the haynes service manual which is readily available online just google it carl salters website i think does it

G · The Voice of Reason Joined: 02 Feb 2002 Karma :

First off, in my experience it's very rare that changing a spark plug makes a decent difference and definitely not in what you are describing.

A stuck powervalve should not make it stutter - it should still go through the rev range, but won't make as much power doing so. Before I sorted the RC servo on my CRM 125 (uses a NSR engine) I would often ride it with the powervalve set to closed and it wasn't a massive difference.

First off, is this happening in all gears?
A revvy bike like the NSR needs to be changed up at decent revs in higher gears, other wise you are not making enough power from low revs to go faster - while if you change in to the gear already at higher revs, it's got enough power.

Is it an actual 'stutter' feel, or just slowing down?

It's definitely worth looking at/cleaning out the carb.

Skinned · Renault 5 Driver Joined: 17 May 2010 Karma :

I had a similar problem on mine. When I bought the bike it had an aftermarket cone type filter. The carb had been rejetted to take it but the bike would still splutter at 6-7k mark. I removed the air filter and but back the standard air box back and filter back in.
I had to mod the airbox slightly to get the right air/fuel mix but now runs sweet, well will do when Wemoto can be f**ked to send my piston kit.
Sounds like after cleaning your airfilter out its now getting more air. Have you got the original airbox with it?

dmatthias77 · L Plate Warrior Joined: 13 Aug 2010 Karma :

Hi Skinned, No it came with a cone air filter as yours did. I am watching an original air filter on ebay. The thing is I have no idea how to adjust the jets on the bike. Your diagnosis seems very feesable, considering the problem started right after I cleaned the air filter.

Can u offer any advice on how I can adjust the settings.

This is a top forumn with some ace guys with advice. Big Thanks to all who have offered there advice to me... Smile

slyrob · Traffic Copper Joined: 03 Jan 2010 Karma :

most likely its the cone filter, Alains on here and www.125ccsportsbikes.com (wealth of NSR info) is the NSR oracle and iirc he strongly advises against using an aftermarket cone filter, if the bike is derestricted the airbox can be modified to suit
____________________
Pitslayer wrote "it could be Ndubz.....ruining this once great place with donkey gobbling loafer knobbing "music".
silky666 wrote "In my eyes, when you shake cocks with the devil, you may as well go for the full reach around"
Villers wrote "as reliable as a ginger stepchild on smack"

dmatthias77 · L Plate Warrior Joined: 13 Aug 2010 Karma :

Just wanted to say thanks for help guys.

Problem now sorted, just thought u wud like to know.

I spoke to me neighbour who builds bikes etc, he took one look at my induction filter ans asked if I oiled it, I said i did as that's what I thought u did to these filters. He said my filter wasnt a sponge one and so it needed to be dry,

I washed it in fairy liquid...dryed it off, and there u have it, accelerates beautifuly.

Im one happy bunny now.....