I took my 21r to a friends place because he just had a 2.5 km straight driveway built on his farm. I warmed the bike up and took it for a thrash. It pulled really well until I got to 180 in 5th redline and went to change into 6th and the back wheel locked up and left a 90 meter black line down his new driveway. When I finally stop (without coming off) I tried to kick her over and there was no movement. I gave it a bit more and it freed up. I got it started again just to try find the problem. The top cylinder seems alright and the bottom has a very erratic exhaust gas release.

Just wondering if this has happened to anyone before and how much damage have I possible done inside.

Cheers

This has happended many times before!

Definitely a seizure. At the very least you should take both cylinders off for inspection. Many posts on the forum with pictures of seized / damaged pistons / barrels, try doing a search.

And do consider, its not just a question of replacing parts, you need to identify why it seized. If not it will seize again.
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Rich
MC21 Track Bike / RS250 NF5 'Spencer', NX5 'Cadalora' & NXA 'Aoyama' / RS500 / Two Brothers Racing RC30

I think it seized because I did the wire splice and left the jetting the same and the warm up was quite brief. I just took the fairings off and also found a little bit of coolant around the bottom cylinder. The reserve tank and radiator are at the same level they were before the breakdown. Is this common when seizing a cylinder?

There's no doubt, it did seize.

Get the spark plugs out and it will be clear which cylinder went, it's normally the bottom one.

Then just remove that cylinder exhaust, power valve butterfly (left hand thread), it's four base nuts and pull it off.

Then post some pics of the damage.
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Please do not PM me technical questions, if you can't find it on the Forum start a thread

The only reason I started this thread is that for a moment I thought it may have been a gearbox problem. Any advice is very appreciated as this bike is still very new to me as I have only ridden it about 10 times. Which at the same time makes me feel like a complete f-wit for doing what I did and how I went about it.

I'll sent the pictures asap. I have been working 140hr fortnights so Time is limited. At the same time I am keen to see the damage.
Cheers
Andy

Andy check out my recent threads Another US Track Day and Oh the Horror. Same thing happened to me last weekend.

Long straight.

Let off throttle.

Boom.

Cry.

You can say that again. I've been crying like a 6 year old girl with a skinned knee for two days. Oh well at least the wife will let me buy that top end rebuild kit now.

I was thinking about just doing the rebuild in the bike unless I find bits of piston in the crankcase. I just don't have the time at the moment to pull it all out.

The spark plugs came out last night and found the bottom cylinder was fine, the top was not so lucky.

I can't figure out the whole uploading pictures thing yet but I'll have a crack at it tomorrow.

Cheers All.

Andy

Andy I use photobucket and copy the last link for the pic. I think it's the one that starts with bracket and img. Just put that link in your post and you're done.

Craig

Cheers Craig, I think I know what you mean but I have a better idea. How about I send my spark plugs to you at my expense and you tell me if there are any similarities between the two cases. Just for a little fun.

I pulled the lower cylinder off this arvo and it looks alright.

Will have another crack at the picture thing next time.

Cheers All

It'd be much cheaper for you to borrow a mate's digital SLR and get some good lighting to take some photos of your plugs

I have a decent camera just lack computer skills. And I did say for fun not practicality. You also get a better look in person than you would with a picture.