The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => A7 1946-1950 => Topic started by: pdg on 24.12. 2016 10:35

Title: feeler gauges for tappet adjustment
Post by: pdg on 24.12. 2016 10:35
I've managed to undo the feeler gauge plugs to find that my parallel-edged feeler gauges won't fit through the access hole. Do "standard" tapered feeler gauges fit, or is it necessary to buy a special narrow set (from somewhere)?

Many thanks, Peter.
Title: Re: feeler gauges for tappet adjustment
Post by: terryg on 24.12. 2016 14:04
Time to break out the scissors and tin snips, perhaps?
Title: Re: feeler gauges for tappet adjustment
Post by: RichardL on 24.12. 2016 14:52
Peter,

I found the following in our section for manuals: http://www.a7a10.net/BSA/A7-47-50.pdf

There is one page in the maunal where they show needed tools and the feeler gauge they show as included in the tool kit has parallel sides. This said, I have zero experience with the longstroke engine and there may be other things at play.

Richard L.
Title: Re: feeler gauges for tappet adjustment
Post by: coater87 on 26.12. 2016 14:59
 Terry,

 If you need odd feeler gauges, you can get individual sheets (yes, sheets) of feeler guage material from companies like Granger. They even sell really long feelers, like 24 inch .004 material. How you would use that I dont know, like trying to push a wet noodle straight up a hill.

 That way you can keep your nice bladed set whole, and not feel guilty about cutting up a sheet to size and shape you need.

 Im sure this stuff is widely available, but most people dont know because they never need it.

 Lee
Title: Re: feeler gauges for tappet adjustment
Post by: RichardL on 26.12. 2016 17:26
Peter,

I'm still curious why a standard feeler gauge doesn't fit. Can you post a couple of pics?

Richard L.

Title: Re: feeler gauges for tappet adjustment
Post by: Tomcat on 27.12. 2016 06:08
I ground the side off the feeler gauge to set the tappets on my longstroke. FYI I found -015" too noisy so now have them at -010"and -012" with no problems. HTH Cheers TC
Title: Re: feeler gauges for tappet adjustment
Post by: Craig on 30.12. 2016 01:31
You need the tapered end type feeler gauges that will fit into the holes.

I got myself one of these.

http://www.ebay.co.uk/itm/DRAPER-36169-10-BLADE-METRIC-FEELER-GAUGE-SET-GUAGE-WAS-73988-/151230072884?hash=item233603c834:m:mxLM_nuhA4fCqhLcMo6C3Vw
Title: Re: feeler gauges for tappet adjustment
Post by: duTch on 29.01. 2017 12:16

 I couldn't answer this at the time, but kept it in mind.

 dunno if it's any help, but the 'recommended method' for adjusting the valve lash on my T100R ('69 Daytona 500) was to bring the adjuster to zero lash, and back it off (can't remember the ##, but ~?/? turn *????*). So @ 1/4" BSF (same as 1/4"BSC) a 1/2 turn would be 0.013".

 easy peasy
Title: Re: feeler gauges for tappet adjustment
Post by: muskrat on 29.01. 2017 19:03
I use that method on most engines to get them close to turn the motor over, then finish with feeler gauge.
26tpi = 0.03846" per 1 turn, 0.0096" per 1/4 turn.
Cheers
Title: Re: feeler gauges for tappet adjustment
Post by: pdg on 29.01. 2017 19:16
All sorted, thanks. Got some tapered feeler gauges from Halfords, and replaced the slotted access plugs with hex versions from Draganfly.
Title: Re: feeler gauges for tappet adjustment
Post by: duTch on 29.01. 2017 21:28

 I forgot to say that the T100  inspection holes are smaller diameter than the 650's so almost impossible to get anything in there anyway
Title: Re: feeler gauges for tappet adjustment
Post by: BSA_54A10 on 30.01. 2017 12:10
Peter,

I'm still curious why a standard feeler gauge doesn't fit. Can you post a couple of pics?

Richard L.
Because the tool kit came with a magneto spannar with had 3 x 5mm wide feelers on it , .012" for the points and an .008 + ,010 for the tappets (assuming I have renmembered the clearences properly )
Title: Re: feeler gauges for tappet adjustment
Post by: RichardL on 31.01. 2017 05:17
Peter,

I'm still curious why a standard feeler gauge doesn't fit. Can you post a couple of pics?

Richard L.
Because the tool kit came with a magneto spannar with had 3 x 5mm wide feelers on it , .012" for the points and an .008 + ,010 for the tappets (assuming I have renmembered the clearences properly )

For reasons unknown to me, it appears I'm determined to get to the bottom of this mystery, though it has no specific usefulness to me.  So, Trevor, how does that explain the valve clearance feeler gage shown in the picture from the manual? I see the magneto spanner in the picture, but why have a picture of a different gage labeled specifically for valves?

Richard L.
Title: Re: feeler gauges for tappet adjustment
Post by: Greybeard on 31.01. 2017 09:41
The feelers I use are parallel. I have no problem adjusting tappets. They might not work for an early A with small tappet covers.