The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => A7 & A10 Engine => Topic started by: Tukig on 15.04. 2013 18:27

Title: Cam follower block grub screw
Post by: Tukig on 15.04. 2013 18:27

Hello everyone,
Just returned from a 80 mile ride in the sun. On checking the bike over I found that the tappet block grub screw and ball bearing were not where they should be ie. in the threaded hole in the flange at the rear of the barrels. Luckily they were caught by the magnetism of the magneto and were sat neatly on top of it. You don't get that kind of service from a coil set up!

The screw and ball seem to screw in securely to the correct depth but I would like some input from the forum members as to if any thing could have gone astray inside the engine. The bike sounds fine.

thanks

Title: Re: Cam follower block grub screw
Post by: a10 gf on 15.04. 2013 19:38

Quote

Luckily they were caught by the magnetism of the magneto and were sat neatly on top of it. You don't get that kind of service from a coil set up!

*smile* one of the more funny (and positive) stories I've ever seen on the forum.

Title: Re: Cam follower block grub screw
Post by: muskrat on 15.04. 2013 22:07

G'day Tukig. The pin that the ball & screw locate is normally a tight fit and I don't think it will fall out with the barrels on the cases. Use a mirror and light to see that the ball will locate in the groove of the pin.
On the down side and I don't want to alarm you but if that one came loose I'm wondering about the other two screws on the inside. These screws and pin stop the followers dropping out when the barrels are lifted.
Cheers

Title: Re: Cam follower block grub screw
Post by: Zen Up 67 on 27.04. 2013 23:43

Quote "On the down side and I don't want to alarm you but if that one came loose I'm wondering about the other two screws on the inside."

Hi all,
On doing a rebore I also replaced the cam followers on my 1960 A7SS 250 miles ago and so had cause to mess around with these grub screws, I think I remember that the ones on the inside are up against a crankcase face so won't unscrew too far, where as the external one with ball has come loose on mine too! Its one of the things I check and tighten after a run!

Title: Re: Cam follower block grub screw
Post by: Tukig on 01.05. 2013 11:14

Thanks,

I little good news from someone who had similar is always reassuring.

Gary

Title: Re: Cam follower block grub screw
Post by: JulianM on 02.05. 2013 07:45

Little tip for locking these type of things,

Smear a little bit of silicone sealer over the end or the head after fitting,  just a little blob not a neat seam though.  Works extremely well even in places that shake out locktited bolts.

Regards,
Julian