The motor in my project 21 has been sitting for about 14 years unused, it was a runner before being laid up so what if anything can be checked without a complete stripdown?
I know i should strip it completely and that was the plan but time and funds are running short so if i could run it for a couple of trackdays this year then tackle it in the winter that would be ideal.

Wow! A truly open question, I'm afraid.

I've heard of bikes that have sat for years, and fired up with virtually no hesitation at all, and seen some incredible things in Asia, where working in the street, or on dust, dirt and sand, by the side of the road is commonplace, but we've also had bikes in that have been claimed to have been looked after (or even rebuilt!) that have been a disaster waiting to happen... and in one case, had already happened!

My personal point of view, and not from a business aspect, but from a practical one, is that the motors, and [new] parts for them, are getting increasing harder, and more expensive to source. I would recommend looking inside it much sooner, rather than later. It will cost less, and be easier; and could possibly cost substantially less, if the centre crank seal looks anything like either of the last two we've had in:





Worryingly, both customers claimed they had come out of [poorly] running bikes! One had been sold his bike, with the seller claiming "it just needs a dyno setup"!

Unfortunately, only one of those was caught in time. The other also ruined the crankcases.

I guess it comes down to how lucky or brave you're feeling, and particularly how the bike was stored. However, we are now seeing bikes that are being regularly used, with seals failing sooner and sooner, which we're thinking could be down to the higher and higher ethanol content in modern fuels.
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Andy.
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Sod it im stripping it im not into false economy.

On the subject of the seals i take it you've already looked into seeing if reproducing them would be viable?

We look into most parts that are NLA, depending on popularity. Other parts can often be substituted. Some discontinued MC16 seals for example, while being different to later bikes, can still be substituted with their later equivalents.

The centre seal for the 89~97 motors is part of the centre bearing. We've looked into reproducing the 87~88 centre seal, but the only people we've found who will do it, will not rate them to 13,000rpm, which is what we need. They will only rate to 10,000rpm.

You can check for a "good bad" centre seal with a leak down test, and a "bad bad" centre seal with the fuel-in-crankcase test.

As a very general rule of thumb, providing the bike runs, but runs poorly:

• If it leaks fuel across the centre seal quickly, the centre seal is buggered!
  
• If it leaks fuel across the centre seal slowly, but a leak down test drops pressure quickly, either one way or both ways, it's buggered!
  
• If it holds fuel, but the leak down test drops pressure, it's buggered, and on the way out!
  
• If it holds fuel, and holds pressure, it's new!

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Andy.
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You know what if im pulling it apart i may aswell go the whole hog and have the crank done, atleast then when its back together its only going to be coming apart again for a top end.

You have all the parts in stock andy? I do have 2 crank bearings that luke very kindly gave me with the fairings.

Luke's a good lad, isn't he!

Yes, we have many parts in stock, including crank service parts.

I don't suppose one of those bearings he gave you was a centre one, was it? We're getting low on those already!
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Andy.
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Aye Top man is luke.

Only had a quick look at the bearings but there both the same and i dont recall seeing a seal so they can't be the centre bearing right?

Yeah. In that case they will be outers.
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Andy.
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