NSR rebuild

monkeyman · Scooby Slapper Joined: 26 Jan 2004 Karma :

My 2001 NSR until today would idle quite happily when it was warmed up. but today i went for a long ride and did give it some stick. Anyway then every time i stopped or pulled up at lights etc it would just die.

I also noticed although it may just be in my head that after about 10 mins of riding it, i was having problems getting it up to the power band i.e it gets to about 7k and runs a little rough just like it does when its cold until you push through to about 9k where as it sounds fine.

Any help would be greatly appreciated.
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Im not the best, but im in the top one
RM 250, Husky TE610, K1 GSXR 750

alains · World Chat Champion Joined: 08 Jul 2004 Karma :

do you said "when i put the lights on" ?
anyway check :
- sparkplug color (if too rich or poor or too much oil) . main jet screw (tight fully then unscrew 2 1/2 turns) will adjust the mixture
- if the sparkplug is black and carboned , adjust the oil pump (take off oil pump cover , untight the under nut then with the upper nut adjust and tight both when ok)
- level of battry charge (must be 12,4 to 13,2 volts) . a battry which not keep the charge needs replacement
control is simple : put in charge for 6-8 H at 2Amps MAX . the voltage must reach at least 12,8 . live it for a while and check voltage time to time(at lest 1/2H) if the voltage go down more than 0,3 Volts , replace it
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the worst day fishing is better than the best day working

mr jamez · World Chat Champion Joined: 04 Aug 2003 Karma :

monkeyman · Scooby Slapper Joined: 26 Jan 2004 Karma :

Its just had a new battery last week, and the starter motor sounds fine so i think its holding enough charge.

I dont rag it when its cold, i just happened to do it once or twice before i knew the damage it was doing so i doubt its anthing to do with that.

I will look at plug tommorow but im pretty sure the oil mixture is fine.

I was wondering if it may be the carb, i.e its closeing to much.

I dont really no, but ill try the plug tommorow

cheers for the help
____________________
Im not the best, but im in the top one
RM 250, Husky TE610, K1 GSXR 750

monkeyman · Scooby Slapper Joined: 26 Jan 2004 Karma :

unfortunately none of these things have done the trick. and it is becoming apparent that it is getting worse.

After a 20 min ride it still doesn't want 2 go from 6k - 7k after that its sounds fine but it takes like 5 seconds 2 push through.

I have also noticed that it idles fine when i start it for the first time without the choke (very unusual) then when i go for a ride it wont idle at all.

So i've decided as the bike has no service history and previous owner did not know when it was rebuilt last i will try and rebuild it for the bikes sake and for personal interest really.

i'm pretty confident with spanner but have never done anything as big as this.

i've read a similar post witch lists all of the parts i should need, i was wondering:

1. Is it worth getting a completely new barrel or should i just send it off to stan stephens and get it welded and plated again (if needed)

2. What does a full rebuild entail.

3. where can i get a service manual for a 2001 nsr

4. what sort of timescale am i looking at from start 2 finish

5. what sort of figure am i looking at for a full rebuild with a new barrel and piston.

Any help would be appreciated, it hurts me 2 see my bike this way
____________________
Im not the best, but im in the top one
RM 250, Husky TE610, K1 GSXR 750

mr jamez · World Chat Champion Joined: 04 Aug 2003 Karma :

Do a compression test first, it should be around 142PSI. I just did a rebuild, including a new barrel, you need to strip it down first to see what is damaged. The barrel will probably be OK, but you may want to replace it anyway. It is cheaper to buy a new barrel than it is to get it replated.

I dropped the engine out of the bike to do the rebuild, makes it so much easier. Barrel and piston is £85, piston rings are £22 and cylinder heads are about £20 (if you need one) then of course the base gasket, head gasket, small end bearing, gudgeon pin, circlips, RC valve dust seal, exhaust gasket. I also bought new cyclinder head/exhaust port studs and nuts to save the bother of getting the old ones out. The rebuild cost me over £150, but I had extra parts on top so it wont be as much for you, I bought all the parts from david silver spares.

It took me 2 hours to fit the new parts, the only tricky part was fitting the rings on the piston. As for a service manual, they pop up on ebay every now and again as having it in front of you helps, I think Ste is hosting the manual but I don't know if he wants that to be common knowledge Razz

monkeyman · Scooby Slapper Joined: 26 Jan 2004 Karma :

I got in contact with david silver spares and he wanted some more information, so here i am

How do i find out what barrel,piston and rings i need are.
I.e A,B,C,D or E.

Could anyone explain what a RC valve dust seal is please?

Cheers
____________________
Im not the best, but im in the top one
RM 250, Husky TE610, K1 GSXR 750

mr jamez · World Chat Champion Joined: 04 Aug 2003 Karma :

The type of barrel and piston you need will be stamped on the bottom of the barrel, just a single capital letter. The piston is unmarked. The RC valve dust seal is fitted into the recess on the barrel where the power valve shaft is fitted, it is just to stop exhaust gas escaping out the side. You will need a new one as the old one will probably get damaged when you remove it.