The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => A7 & A10 Engine => Topic started by: michael snellin on 10.10. 2012 18:38

Title: Camshaft tappet !!!!! And chain case
Post by: michael snellin on 10.10. 2012 18:38
Hello, every one, does any one know and (i am sure there is) on the a10 barrell, there is a grub screw with a 3/16 ball and a locating pin, two screws at the end, havent got a clue as to what they do, and can they be fitted when barrell is fitted also is there a spacer req on the clutch case at the rear  end, its just want to do this bike correctly.
Title: Re: Camshaft tappet !!!!! And chain case
Post by: MG on 10.10. 2012 18:50
Hi Michael!
The parts you mentioned prevent the cam followers from falling out of the cylinder barrels if the latter are lifted off the crankcases. The longer grub screw is the only one that is accessible with the barrels fitted. The ball is located under that screw, at the rear of the barrels, right in the middle between the cylinders. The locating pin and two shorter grub screws are inserted in the tappet block before the cylinders are fitted on the cases.
Ref the spacer for the inner primary case half: You have to tighten the bolts securing the primary case to the engine case first, then add a washer/washers or spacer accordingly, in order to get good alignment and not warp the inner case when tightening to the frame.
Cheers, Markus
Title: Re: Camshaft tappet !!!!! And chain case
Post by: michael snellin on 11.10. 2012 14:10
Thanks to M.G. for your help on the above script,as i have purchased this bike as a basket case,urgh !! at the moment, i have no tappets/cam followers or push rods, had the barrell, bored out to 60 thou can i go ahead and fit the barrell without having the tappets/cam followers as the locating pin on the barrell  has two flats and i am not to sure what way round this should go.any help is very much appreciated.
Title: Re: Camshaft tappet !!!!! And chain case
Post by: MG on 11.10. 2012 20:25
Nope, the cam followers have to be fitted first, then held in place by the two grub screws and the locating pin, which in turn is held in place by the ball and longer grub screw. The locating pin is fitted with the flats facing sideways (ie the flats aligned vertically), the groove facing backwards. The exhaust followers have two additional flats machined on the rounded off side, that's where the locating pin fits in. The tiny ball engages with the groove in the locating pin. All has to go in BEFORE the barrels are fitted!!!
Hard to explain, but you'll see immediately how it all goes together when you got a set of followers at hand!
Best, Markus
Title: Tappets etc !!!
Post by: michael snellin on 12.10. 2012 09:49
Marcus, well done you have now answerd all my questions re, the above items,.
                                         thank you.
Title: Re: Tappets etc !!!
Post by: A10 JWO on 13.10. 2012 13:15
Hi Mike
Is that the red A10 I saw in your workshop last year. Mine is running great. Hope to see you for a cuppa soon.

Colin
Title: Colin Hi,
Post by: michael snellin on 15.10. 2012 18:00
Hello.Colin, yeah !!  thats the one spk soon,