BSA Owners' Club Forum

The BSA Workshop => Twins => Topic started by: Caulky on 30 September, 2017, 16:45:33

Title: 1971 A65L Piston hitting inlet valve
Post by: Caulky on 30 September, 2017, 16:45:33
And it was going so well....
I fitted the inlet rocker gear and was about to fit the exhaust rockers.
Then I put the right-hand pushrod on, turning the engine with a spanner on the alternator nut.
Watched the valve opening, then it locked.
With the adjuster fully out it will turn-over completely.

This is a head off job now.
There could be many reasons for this to happen, just about everything is new.
I'm thinking, wrong camshaft, wrong followers, wrong pistons, etc.
Any thoughts? 
Title: Re: 1971 A65L Piston hitting inlet valve
Post by: Mike Farmer on 30 September, 2017, 17:20:24
Hi

Please don't be insulted. Have you got the push rods in the right position???

Mike
Title: Re: 1971 A65L Piston hitting inlet valve
Post by: Caulky on 30 September, 2017, 17:28:31
Well. I think so, short ones outside.
Title: Re: 1971 A65L Piston hitting inlet valve
Post by: DEREKANDERSON8 on 30 September, 2017, 17:48:32
Valve timing is all ok i presume?
Title: Re: 1971 A65L Piston hitting inlet valve
Post by: Caulky on 30 September, 2017, 18:15:38
I have not really had a chance to check the valve timing, but the inlet is open at TDC, which confirms my suspicions.
Title: Re: 1971 A65L Piston hitting inlet valve
Post by: DEREKANDERSON8 on 30 September, 2017, 18:29:58
sounds like the problem  ;)
Title: Re: 1971 A65L Piston hitting inlet valve
Post by: Caulky on 04 October, 2017, 18:16:32
Preliminary checks appear to show that the inlet valves are beginning to open far too early.
But, I can't find my degree wheel, so I'll make another to check it out.