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Sorry to hear you're having such a hard time with the timing. Wish I could help but I don't know a darn thing about them. Good luck hope you get it figured out and please don't give up!......Gary
 

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What about using original BSA ( sport ) camshaft, I found it very good during my 10 years of A65 ownership.
It worked very well with one carb Thunderbolt head and small port 2 carb's Clubman head and was "too sporty" for the big port, big valve late head. Going into even sportier aftermarket camshaft will make your bike really difficult to ride in town and in traffic because of low torque below 3500 rpm.
 

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Discussion Starter #304
New exhaust rocker gear arrived and fitted, but there's a problem.
Even with adjusters fully undone and the cam off the lobe, the pushrod wont fit.
I seem to remember a similar thing happening when it was dismantled.
Both exhaust pushrods are the same length 7 3/4".
Maybe the valve stems are too high?
(In the pic, the pushrod is towards the camera).
I've a feeling this means, head off!
 

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Discussion Starter #305
Head off, its been skimmed.
I need a thick head gasket.
This will lower the compression ratio, not a bad thing with today's fuel.
No evidence of valve clash, but I did stop turning the engine immediately I felt resistance.
 

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Discussion Starter #306
Back when I had the problem above, I took it to my machinist mate.
I could tell he had very little enthusiasm by the way he was making excuses. 'Copper no, it will damage my mill cutters, etc.'
Then I had a lecture about the properties of various metals.

So, I had to hand-make my own, nil interest set in and I have just about finished it. (not an easy job).
It is fashioned from 2mm copper sheet. Original is 1mm thick.
Cutting and filing the profile and de-burring is a pita.
There is a problem with the hole/s alignments, but there was also with the original.
The holes will need to be expanded in certain directions.
After annealing and fitting, I will add a few lbs/in when torqueing. 5-10?

I have some copper spray (1100C) to aid sealing.
 

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Hi Caulky, I had a similar issue when rebuilding my A65 , Have you had oversize inlet valves fitted , it looks like it. If so I strongly suspect your inlet valaves are coil binding. this is because they sit further into the combustion chamber, there are two solutions, fit longer valves ( might be unobtanium) or have the seat cut deeper. You can check for coil binding easily, all the spring gaps will disappear.

On another note, nice to see some weel kent faces here, folks I have come to know from the britbike forum,, I will spend more time here I think.
 

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Discussion Starter #311
Hi Code Man

I don't seem to have time. Generally lost interest in bikes. My time is taken up with home studying for a second (honours) degree in Earth Science.
This follows on from Geoscience.
Very mature student :smile2:
I will do a bit after the June exam, hopefully!

Dave
 

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Hi Caulky, so you're into earthquakes and volcanoes now! Interesting stuff that's for sure. I do want to thank you for the video you put on YouTube that taught me how to put the 5 speed transmission back together on my T140V engine. The video was easy to follow and the tranny worked great first-time around.

Good luck with your studies. You're an interesting person!
 

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Discussion Starter #313
catch 22?

Hi all
After making a 'thick' head gasket (2mm copper) I thought all would be ok.
The inlets were ok after lifting the head a shade, pushrods in.
Now it was time to torque the head bolts.
Exhaust rocker gear fitted, exhaust rocker still arm too low. Can't fit the pushrods!
And I cant raise the head because its torqued.

As mentioned by GavinE, I have had a head job done, seats cut too deep? springs binding?.
I wonder if its possible to buy shorter pushrods?
 

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Discussion Starter #314
Job done!
After posting the problem on the BSAOC forum, it was revealed that the exhaust rocker gear has to be assembled with the pushrod cups engaged into the rocker arm balls.
This makes a fiddly job even more difficult.
 

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The inlet rocker spindle is pinching one of the thackeray washers and isnt fully home. Looks like the furthest away thaackeray.
 

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The rocker shimming spacers go like this, from Drive side. Plain washer, thackeray, rocker, plain washer. centre boss, plain washer , rocker, thackeray, plain washer with reduced ID.end boss, washer , nut.

( too late for this now) prefit the spindle with nothing else except the reduced ID washer and note how much overhang is present at the DS spindle end, measure this, check this measurement is the same on final assembly.

It help to heat the alloy bosses when moving the spindle. When done correctly all washers should spin freely except the last one with reduced ID which is trapped between the spindle shoulder and the boss.
 

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Discussion Starter #318
Gavin, I'm glad you mentioned this, the right washers were bound-up.
But worse still in my haste I assembled the exhaust rocker gear in the wrong sequence.

Left inlet valve timing looks OK.
Pic with clock has just moved a fraction, degree wheel pic shows 51* BTDC at .015" gap.
Exhaust tomorrow.
 

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cam timing

Spot on at Inlet 51 degrees BTDC opening, I usually check all opening and closing figures, twice, expect a 2-3 degree variation.
If the inlet is good , the rest should fall into place.:smile2:

It still looks like the inlet rocker spindle isnt fully home, it has more protrusion than the exhaust, normally these are equal.
 

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Discussion Starter #320
I removed the right rocker gear and the shaft protrudes the same amount.
I'm thinking the taper on the shaft is different.
However I will remove all of the rocker assembly and do a check.
 
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