Pics at last!

[Old Fogey]

Very very nice!
What color is it going to be,,,,,,,,, BLACK?

Guess you missed this previous post, Chef.

http://www.ngwclub.com/forum/viewtopic. ... c&start=90

[Cookie]

Good move for an old cabdriver. I never would have thought of that.

[Old Fogey]

Finally got the front Comstar mounted up and the brakes sorted out.

After a hunt for a 79 axle nut, availability of which is on a par with unicorn horns over here, I used the new 76 nut which is 5mm shorter ( thanks to CYBORG for measuring that for me) and the old spacer on the other side with a 5mm spacer both sides. Stainless spacer cost £3, new OEM nut and spacer £35; no contest!





I still like the look of the spokes better but at a cost difference of around £350 I think I can learn to love these

The little problem I had as to what to do with the cable bracket on the fender stay was solved easily after all. I just twisted it round to the inside after thinking about it for months. Sometimes the easiest solution is just staring you in the face all the time.




Where's the cable?

Ah, well. It wouldn't do to have things go right now would it!
The old cable was 6" too short so a new one was bought.
Yeah! right! only 6" too long this time.

It never fails.

[Cookie]

With 6'' too long you can just loop it around your elbow. Seriously can you find a way to run it a to take up some slack?
The front end looks pretty good to me.

[Old Fogey]

Thanks Cookie.

Its more like 8" to be honest and that's with the forks at full extension. I'm going to leave it for the moment until I get it down on it's wheels; it's a very minor detail really.

[Old Fogey]

Well, its been one of those days

I was told by the engineering shop that my stuff would have all been measured up, if not actually bored, out by today. When I get there nothing, but nothing, has been done!

On top of that, they reckoned that, because of the blind bore on the crank support side of the block, it was going to cost £120+VAT=£138 / $195 just to do the boring

Then 4 pistons sets totalling £280/ $395 on top of that.

So I took it all away again for a rethink.

The new decision is to de-ridge the bores, which have some wear in them mainly on the thrust side as you'd expect, and re-ring the original pistons which measure up about half worn. Not what I wanted to do at all but in the current climate it seems the best solution as new rings are about £25 / $35 per piston.
I should get a couple of years out of the engine this way as I don't see me putting an astronomical mileage ont it each year.

Because there are no markings on the bearing shells for the conrods the journals have to be measured and the new bearings calculated from that.

Theres a query here too.

The shells in this engine have no oil hole in either half although there is the same oil orifice drilled in the conrod as on the 76 rods which do have oil holes in the aftermarket shells, in both halves. Since there is no separate numbers for half shells with or half shells without I guess that the 76 rods are correct.
Most peculiar!


So now to the crank.
OK, need to buy a mic that can measure down to 0.001mm

Now, for those of you how can't envisage that, a human hair is roughly 4 thousands of an inch in diameter. Now divide that by 4 and you have 0.001".

Now divide that again, by 25!!!! This will give you 0.001mm

Needless to say, these mics sure ain't cheap!

However a couple of hours searching the net and I've got one on its way.

Progress at last. Sort of.

[Cookie]

Can they knurl the pistons for you to cut slap? I've had very good luck with several rebuilds this way. They start getting a bit loose again after 40,000 miles or so, but it would seem that could give you several years.

[Old Fogey]

Good question, Cookie. I've heard of this but never seen or had it done.

I would need to find another shop to do it. The one I went to is the best but they are absolutelysnowed under with work, mainly major stuff, so my little jobs are more nuisance value than anything else.

I still have another option which would be as cheap as having that done. Silver is selling standard pistons at £10 each, thinking hard about doing just that.

[Cookie]

If you can drop a new standard in the bore and measure the clearance with a feeler guage you will get an idea where you are. Usually just the amount of ridge you cut off gives you an some feeling about wear.
A few years back we re-ringed engines without boring very commonly.
Knurling can take up side slop that a standard piston can't. It might almost be tough to find someone who can do it as we live in such a throw away society these days.

[Neil]

That front wheel looks really good. Are you happy with the stainless brake lines you have

[ElPiloto]

I have used knurling on brand new pistons. The knurled area holds oil and lubricates the pistons better.

Knurling was very popular in the 30s, 40s and 50s when everything was repaired, not discarded.

There are 2 ways to knurl a piston. The first is to use a knurling machine. You clamped the piston, upside down, and tightened the knurling wheels and twisted the piston back and forth by hand until the knurl was finished. Needless to say, these machines are very rare now.

The modern way is the chuck the pistons up in a lathe and mount the knurling wheel in the tool holder. Then you can move the piston back and forth by hand until the knurl is done on both sides of the piston.

If there is an auto repair shop that has been around for 50 or 60 years, they will probably be able to do it. Most young mechanics have never heard of knurling.

[Old Fogey]

That front wheel looks really good. Are you happy with the stainless brake lines you have

In a word. No!

But they came with the bike, they are in good condition although not like the modern versions that have a vinyl or PVC covering.
So they will do the job until the financial view improves.

[Old Fogey]

I have used knurling on brand new pistons. The knurled area holds oil and lubricates the pistons better.

Knurling was very popular in the 30s, 40s and 50s when everything was repaired, not discarded.

There are 2 ways to knurl a piston. The first is to use a knurling machine. You clamped the piston, upside down, and tightened the knurling wheels and twisted the piston back and forth by hand until the knurl was finished. Needless to say, these machines are very rare now.

The modern way is the chuck the pistons up in a lathe and mount the knurling wheel in the tool holder. Then you can move the piston back and forth by hand until the knurl is done on both sides of the piston.

If there is an auto repair shop that has been around for 50 or 60 years, they will probably be able to do it. Most young mechanics have never heard of knurling.

Do you reckon a centre punch, small hammer and a few hours might do the trick?

[ElPiloto]

I was able to reuse the pistons on a Yamaha 2 stroke by using a punch and hammer. Just don't hit the punch too hard. A worn or rounded off punch works really well. If you use a spring loaded automatic punch, all the dimples will be the same.

[Old Fogey]

I was able to reuse the pistons on a Yamaha 2 stroke by using a punch and hammer. Just don't hit the punch too hard. A worn or rounded off punch works really well. If you use a spring loaded automatic punch, all the dimples will be the same.

Really??

Well, you learn something new every day! And I thought I was joking.
I have an old spring centre punch. Hmmm-- food for thought there.

Wonder what Mother Honda would think of punched pistons