NSR rear wheel locked up

[Hadies]

Hey all. Just had a scary moment. I was doing bout 70 and rear wheel locked up. the back end came round and i can't really recall doing anything special but the bike straightened itself out . The revs dropped before the wheel locked up, i pulled the clutch in but the bike still slowed down quite rapidly (was expecting to freewheel) as if i had the brakes on. I stopped by the side of the road and had to get breakdown recovery to take me home because the bike wouldnt start.
I recently changed the engine oil myself with good quality 4 stroke oil because it was as black as the night sky and cleaned the chain and lubed it all up and this was the first time out on my bike since i did the work. I was a bit hesitant on going far because I didnt really trust the work Id done so I rode around for a bit near the house and the gears felt awesome smooth and the bike was fine so I decided to go further. As soon as i did that shit scary thing happened.
The bike had petrol(made that mistake before lol) and plenty of 2 stroke oil.
What do you think has happened?
Thanks all, much appreciated

[rotax81]

as you describe it, i would say it locked up in gearbox but its more like to happen to the engine itself being a 2 stroke.
____________________
ZX636C6F road. ZX636C1H track. ZX7R redundant. ZX0.5R minimoto as ornament.
Audi A4 Avant 1.9TDi and VW Transporter 2.5TDi 888 Special (no mot and tax lol)

[Hadies]

Thanks for the reply. Im a bit of a noob as you probs can tell.
How serious is this? How do you fix it if its the gearbox and how do you fix it if its the engine and the costs involved? Im worried about touching my bike and working on it after today.
As fun as it was sliding around and having to sit in the cold for more than an hour I don't want to risk this happening again.
Thanks all

[rotax81]

you need to start by taking the head off and having a look. if all looks well then check the crank then the gearbox.
try the top end first though.
____________________
ZX636C6F road. ZX636C1H track. ZX7R redundant. ZX0.5R minimoto as ornament.
Audi A4 Avant 1.9TDi and VW Transporter 2.5TDi 888 Special (no mot and tax lol)

[Cigaro]

But you said it stayed locked even with the clutch in.

The chain hasn't come off the sprocket has it?

[Hadies]

rotax81: I didnt understand anything you just said. I'll probs have to get a mechanic to everything you just said lol

bassjunky: nah the chain was still on there.

It slowed down in quite a wierd way. It was as if it was engine braking but a hell of a lot quicker and harder. The road side assisstant didn't even bother looking at it lol. He just said I'll take you home. I was expecting to ride it home.

[Finglonga]

[Cigaro]

Aye, missed that bit.

The oil that you changed would probably be the gearbox oil, and you're supposed to put, well, gear oil in it.

OOPS



edit: quick google says maybe 4-stroke oil is ok after all. in which case, fail on my part.

BUT, I would imagine that it is reccomended to use actual gearbox oil for gearboxes.

[Hadies]

Lol. I did plenty of research on it because it was my first job on my bike and i didnt want to mess it up and i may have. In the service manual it does say 0.7l of 4 stroke oil is what i needed and its what i put. Ive read threads on here where people have put 2 stroke oil where the gearbox oil is meant to go. I learnt from their mistakes

[Cigaro]

Which grade did you use?

apparently should be 10w40.

just clutching at straws, i know nothing about NSR's but i think it does sound like something to do with the gearbox, if the engine had seized it wouldn't make sense that it would be slowing down with the clutch in.

[Hadies]

I used castrol power 1 racing 4T 10W-40. Please tell me this is ok lol

[salty21]

yep thats fine, i used it for near on 12,000 miles on my nsr, can you get it into neutral?, is it still stiff to push?
____________________
04 NSR 125(sold) ---- 03 CBR 600rr(sold) ----90 pan euro ST1100 '' ----02 CG 125
94 CB400 Super Four ---- 2000 VTR SP1 (sold) ---- 08 ninja p8f(sold, meh) ----05 CBR600rr

[Mr Hammers]

That should be ok, i replaced mine recently and had a similar confusion, but the guy at the racing shop assured me it was fine - i went for Putoline 10w-40 - and that was classed as 4T too.

Have you had a look at the bike since? Is the rear wheel still locked, or is it free now? How tight or loose is your chain?

I'm wondering if it could be that the chain has come off the front sprocket. If you take off the sprocket cover you'll be able to see if that's the case, if the wheel is still locked.
____________________
A Guide To Powerbands

[Hadies]

Hey all.
Yes I can get it in to neutral. I had to wheel it down the back alley because the truck couldnt reverse in when it dropped me off. lol

I should've mentioned this before too. When i start it in gear, clutch pulled in, the bike starts to edge forward as if i've got the biting point but dies before it moves much. When i say edge forward i mean a cm or 2. Hope this helps

The chain is definately still on and is tight. Ive been reading around and I hope its not "seized." Not fully sure what this means but it don't sound good.

[Cigaro]

Hadies> how tight exactly is the chain?

Also, do you mean you've managed to get it started, or was this before the incident?

[ZaphodBeeble]

I'm pretty sure the gearbox oil should be 75w oil not 10w/40. The engine oil would be the one under the tank which would be 2-stroke oil. The gearbox is the one with the dipstick.

With the bike in neutral will the engine turn over with the starter?
____________________
Current bike: VTR1000F Firestorm. Previous: Firestorm (written off) - XJ600 Divvy - NSR125 - DT125 and a load of offroaders.

[Cigaro]

[Hadies]

TheBassJunky: The chain is the same tightness as its always been. I havent managed to get it started. What I explained above is what happens if I try to start it.

ZaphodBeeble: The bike wont start in neutral. It just chugs. But as I said above, if I put it in gear and try to start it, clutch pulled in, it edges forward as it chugs.

[joop200789]

the clutch biting point and only a bit of movement, may be that the release arm may have failed or something along the lines,may need adjusting again

[alains]

well , well , well i read a lot of unaccurate posts . the correct gear box oil is 10-40W , quantity of 0.7 is right . it could be the gearbox , but i doubt !
my first think is an engine seizure , the symptom is very often a blocked wheel and when running fast a fall . i hope it's not that otherwise prepare to rebuilt your top-end (if no damage to the conrod) . if you can get in neutral , then push the bike a couple yards , does it move freely ? now engage 1rst gear , can you push the bike ? if yes first and no second you have a seizure
also with a seized engine you will never start
rebuilding a top-end will cost £180 (£200 if the head is damaged)
if the conrod is damaged too , better you fing a 2nd hand engine
obviously cost is without the work if you are not able to DIY
____________________
the worst day fishing is better than the best day working

[Hadies]

Thanks all for the input. I have had someone who has more mech skills than me look at it today.
alains: I can get it in to neutral and push the bike freely and i can also engage 1st and move freely so hopefully it hasn't seized. I was lucky not to fall lol

The mech who came round looked at the spark plug and turns out the bottom bit has blown off and its in the bike somewhere. He replaced the spark plug and it still wouldnt start. There is a spark and fuel is getting in cuz it was wet. In the attempts to start the bike there would sometimes be a wet sounding pop out of the exhaust. Not quite sure what this means. He's in the process of taking out the bit of metal from the spark plug.

[alains]

you probably have a damaged piston , you wont escape of a barrel dismantling in order to look the damages . when this plug break happens , generaly you've got a hole or an edge piston damage and the squish in the head has impacts . taking the head off will tell you a good idea . about the bit of your plug , it's probably now gone through the exhaust . are you going to DIY ?
____________________
the worst day fishing is better than the best day working

[Hadies]

Well the guy managed to get it started by running down the street but it dies if the revs fall below 3000. He too reckons I have a damaged piston and if im lucky the bit of spark plug may be wedged in the piston instead of falling into the engine. Is there any hope if it has fallen into the engine? The mech said i would need a new one if that were the case.
Im not looking to DIY it. I dont have the tools etc. We tried to take the top end off with the tools we had but the nuts were too tight.

[alains]

use a socket spanner (1/2") and you will be able to use an extension . be carefull if you change piston , they are fitted with the barrel and few of mechanics know that . they fit aftermarket standart size at 54.00 mm , which is wrong . the size is determined by the letter hammered under the barrel . if you want an example see https://www.geneva-racing.ch/~alains/lettre.jpg (it's an E) then look the table https://www.geneva-racing.ch/~alains/piston.jpg
for my point of view it's better to rebuilt the top-end £180 and £200 if you need a new head . if you want , i've got a list of spares with refs and prices (all from david silver spares) , i've ordered at least 10 times since last year for my mates in france and i can tell you they are the best prices
____________________
the worst day fishing is better than the best day working

[Hadies]

Thanks alains. That would be great. About how much would all this cost including labour charges on average?