Rebuilding top end on NSR, help needed

bonceunounce · Banned Joined: 22 Aug 2003 Karma :

Right, got all my top end parts from david silver spares this morning.

First problem, cant get the powervalve out, ive got that little spindle sticking out the side of the barrel and ive dug out the rubber seal ive pulled on it like scotty said and it wont budge?

Also the piston doesnt have an arrow on it so i dont know which way round to put it on? The notches on the piston itself that the rings squeeze onto, shoud they be at the back of the barrel or at the front ? Common sense told me they go to the back, but i not sure.

Cheers

Scotty · Scooter Boi Joined: 31 Jul 2002 Karma :

Did you download the manual.
I think theres a circlip in there somewhere stopping it coming out.
me thinks.
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Regards
Scott

bonceunounce · Banned Joined: 22 Aug 2003 Karma :

yeh i downloaded, how come u aint online? i want your tank flap bit.

Now the top piston ring wont sit properly in the piston, just sticks out and doesnt move Twisted Evil

bonceunounce · Banned Joined: 22 Aug 2003 Karma :

this is turning into a proper pisstake!

What the hell is going on with piston and rings?

Right , the picture below is the one im looking at

ive got two rings OFFICIAL HONDA PARTS

it says fit expander to bottom ring part, done that , then it says , on the bottom ring there will be a marking - well not on mine, where it says the marking should be all i have it a 'N' on BOTH rings, on one of the rings the N is bigger than the other? does the N go facing upwards or downwards ?

starting to really get to me now, been at it since 3 a clock and so far all ive achieved is major stress! Twisted Evil

bonceunounce · Banned Joined: 22 Aug 2003 Karma :

dont worry done the rings
Cool

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

Reading the manual both rings should be marked. As I read it they are just saying not to interchange them, ie if you have installed them and used them then do a rebuild and reuse the rings make sure they go back in the same positions. The marks should face up.

The power valve is held in place with a circlip which is under the seal. The shaft will only go into the bits of the power valve inside the exhaust port in one position.

The gaps in the rings should sit over the small pins in the ring gaps (it stops them rotating round the piston), and those pins should point towards the back of the engine.

All the best

Keith
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bonceunounce · Banned Joined: 22 Aug 2003 Karma :

Cheers keith thats brilliant

The poweralve wont budge, i dug and dug at that damn seal and it just comes out in little bits , also this spring has came out a really thin fine long spring which is half stretched.

I think ill just buy a new powervlave before i go insane

cheers

bonceunounce · Banned Joined: 22 Aug 2003 Karma :

okay. still wont budge

ive attached a picture of how the manual says to remove it.

so far ive got nearly all the rubber seal out, then i was left with a gap down the side of the 'shaft' about half an inch.

I scraped around that with razorblade to remove more welded on rubber and this dodgy spring came out, bout 2 inch long in total half stretched??! were th fuck did that come from and i cant see no 'e' clip as they call it on there, if there is one, it must be about a inch down inside the barrel which is going to be near impossible to remove. Like scotty said his barrel powervalve didnt a 'e' clip or circlip???!?!

Im thinkin of sticking the side of the barrel on the bench grinder and grinding away the side but ill probs just shag the powervalve then Rolling Eyes

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

The seal has a long small spring as part of it. You are probably most of the way there.

All the best

Keith
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Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

Scottys did have a circlip , but it didn't survive being removed! Once the seal of out I think the shaft should just come out.

All the best

Keith
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bonceunounce · Banned Joined: 22 Aug 2003 Karma :

it must be to do with the way the RC valves inside are.

shud the two valve bits in the exhaust port be down or up when taking the shaft out?

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

Don't think it matter whether they are up or down. Just pull firmly and carefully (be careful not to bend the shaft). Remember that the shaft and those flaps have been subject to loads of heat and exhaust gases for the past decade.

All the best

Keith
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bonceunounce · Banned Joined: 22 Aug 2003 Karma :

i totally give up, ive pulled and pulled and it wont budge it sort of comes out about 2mm and stops and goes back in.

cheers
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Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

Take the barrel along to a local motor engineer / decent bike shop. They can probably hoik it out in 2 minutes flat.

All the best

Keith
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bonceunounce · Banned Joined: 22 Aug 2003 Karma :

anyone fancy a tug?
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bonceunounce · Banned Joined: 22 Aug 2003 Karma :

solved it, bloody half mettal half rubber thick washer thing stopping it, dug it out with a homemade screwdriver on the bench grinder!!

Cheers Razz

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bonceunounce · Banned Joined: 22 Aug 2003 Karma :

What about running it in? its a whole top end ive replaced.

cheers
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Scotty · Scooter Boi Joined: 31 Jul 2002 Karma :

Well tis what i'll be doing!
I imagine not to bollock the bike, try keep it below 5k i imagine,
but vary the throttle every now and again i think.
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Regards
Scott

bonceunounce · Banned Joined: 22 Aug 2003 Karma :

lol will be fun.

This bike is taking the piss out of me, so far i managed to get the new piston and rings onto the conrod and fit the new base gasket.

Went to put the powervalve shaft through the new barrel , through the valves, and it stuck out about half inch? The valves still turned, but the shaft woulndt go all the way through, so , i pushed it a little harder and it went in, great i thought, then the friggin valves wont turn in the exhaust port Twisted Evil

so took it to bits and it works with 1 valve but not 2 valves!! Now what in the soddin hell is going on!!ARGHHH Twisted Evil

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Scotty · Scooter Boi Joined: 31 Jul 2002 Karma :

imagine all the trouble if it was a 4 stroke you'd be having Very Happy

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Regards
Scott

bonceunounce · Banned Joined: 22 Aug 2003 Karma :

lol

that bike really does hate me

went to change a blown headlight bulb, i squeezed to hard and it shattered and ive gashed my fingers and wont stop bleeding, been bleeding a good 2 hours nice big bloody gash in my index finger Twisted Evil

does anyone know which cable goes were into the RC valve case? i though the springed one goes in the right hand side and te cable with 2 nuts on goes on the left?

put ignition on, it just makes a creek sound and i can hear the rc valve motor buzzing as if its stuck? Rolling Eyes

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Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

Disconnect the cables from the servo. The turn the ignition on and allow it to reset its position.

The one with the spring goes on the right (ie front of the bike) as you said.

As far as I can make out the cable with the spring connects to the servo motor nearest the frame.

Make sure you get the cables the right way round or it will do all sorts of odd things (such as have no power). Also make sure you adjust them correctly as if the cables are too tight you stand a fair chance of burning the servo motor or its control unit out.

All the best

Keith
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bonceunounce · Banned Joined: 22 Aug 2003 Karma :

okay keith cheers

Its okay, ill maybe loosen one of the nuts off a bit, even tho it was just finger tight, spins okay.

So far ive got the new top end on, engine back in the bike (when i can find the big allen key!)

Just got to put all colling hoses on, electrics bits in, carb and airbox and see if she fires up!!

Turns over great now!

Me very pleased, i just hope something doesnt happen with the powervalve and shag my new barrel, tho i wont be going fast enough to open and close it Rolling Eyes

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bonceunounce · Banned Joined: 22 Aug 2003 Karma :

Its all done!

Been out all night! Im so happy

Took me all day, rebuit the engine putting all bits back on.

Its a shitter getting over taken by 50 riders.

What is a good rule for running in?

Ive been riding at 5 - 6000 rpm , max speed 45 - 50mph

But how many kms for?

Cheers
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Hex · Party Boy Joined: 04 Feb 2002 Karma :

Been covered lots of times how to run in mate if you do a search. Basically you want to vary the revs and keep under certain limits (about 7k for so many hundred miles etc).

Normal running in period is 500 miles.

As said do a search and you should find loads on it as its been covered a lot of times before.

Hex
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