Posts Tagged ‘SRM’

The Lightning Project… part eleven.

Posted: November 10, 2016 in Just Me
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Now where was I?

With the head all bolted down, and the rockers installed, it was time for those new SRM tappet adjusters to be fitted…

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SRM tappet adjusters

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SRM upgrade

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Tappet angle

Next on the list was cleaning and refitting the exhaust system…

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BSA A65L motor

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Original exhaust re-fitted

So I am getting there slowly, I need to order a few small parts, rocker cover studs, headstock bearings, and I still need to find some forks, but so far so good.

 

Pulling it all apart, putting it all together.

I have now for the moment taken the motor as far apart as I intend to go for the time being. I have drained and flushed through the crank cases, and was pleased to find no metal in the drained oil after letting it stand in the tray for a week, and filtering it off over a strong magnet.

The cylinder head has gone off to SRM in Wales for full refurbishment, which includes lead free seats, new guides, valves, springs etc. This work wasn’t cheap by any means, but it should last me out, and make for a good top end. I am looking forward to getting the head back so I can button up the top end.

Last weekend I cleaned off all the old base gasket material, and fitted the new pistons, I also honed out and painted the barrels ready to be fitted. I would have fitted the barrels but the supplied base gasket in the kit I bought was for the 1/4″ stud version cases and not the 3/8″ as required on the later cases, so again I find myself waiting.

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New +20 pistons

Next I turned my attention to the front end and dropped out both fork legs, water had got in through the torn gaiters, and was evident in both legs, water came out of the right hand side, but the left hand stanchion is at the moment seized solid. So I have left it soaking in some penetrating oil for the week, I shall see how it does this weekend.

The Lightning Project… part six.

Posted: September 30, 2016 in Just Me
Tags: , , , , ,

SRM.

I just ordered and received this new SRM magnetic sump plate assembly for the BSA Lightning. The quality is outstanding as I hope you can see from the pictures.

I also sent my head off to SRM to have new valves, guides etc. It is right about now that I hope the bottom end is all ok! everything seems fine but I won’t know for sure until I fire the bike up. A scary thought.

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SRM sump kit.

http://www.srmclassicbikes.com

 

The next step is to remove the head, so we can check the condition of the combustion chamber, the valves, the bores, and of course the pistons. Somewhere in here is the reason for the low compression in the right hand cylinder, it is just a case of checking out the parts as you see them.

The valves seem fine, and have no leaking, so that really only leaves the piston or rings.

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Valves

Now we get the heart of the matter, the first look at the bores, and piston crowns, there was a fair bit of carbon build up, which I have started to clean off the pistons. There is slight scoring in the bores showing signs of previous trouble, a minor nip up, or a ring broken in the past.

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A65L barrels and pistons

The barrel just needs a light hone, and will be good to go, the piston crowns show +20 so there was a past problem hence the signs of previous scoring, and with the barrel removed we find the cause of low compression, the rings are all stuck solid in the right piston, nothing too major then.

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+20

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Stuck rings = low compression

Right time to strip and clean all the parts, hone the barrels, new piston kits, valves, valve guides etc, and start building it back up.

The label on headstock says it all… February 1970 A65L.

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BSA Label

So that is where I have started, and now I start sorting parts, finding what’s good, and also what’s bad. And ordering new parts as I start to get the bike back on the road where it belongs….

As I intend to pull the top end, I have started getting a few parts for that area, de-coke gasket set was first, and while looking at the SRM site, I saw these nice tappet adjusters, which arrived today…

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SRM tappet adjusters

I have also ordered the new fork gaiters, and some stainless cable guides, but a list shall be made of required parts before the next Kempton jumble in a couple of weeks.