The BSA A7-A10 Forum

Technical => A7 & A10 Engine => Topic started by: JohnH on 25.07. 2010 19:05

Title: A10 Pushrod alignment tool
Post by: JohnH on 25.07. 2010 19:05
I have been studying these forums and other web based resources a lot before I start to whip off my GF top end. I've already had tremendous help on the gasket cement front (thanks to all!). It's become very clear from my research that getting the pushrods properly aligned can be an enormous faff. So, come on you experts ... is it?

Those in the know seem to swear by the use of a pushrod alignment tool. I love to make my own whenever I can and I wonder if anyone has a drawing or dimensioned set of photos that they might be prepared to share. Having said all that, I'm expecting someone to give me another brilliant piece of advice that makes such a tool completely redundant.

Thanks.
John
Title: Re: A10 Pushrod alignment tool
Post by: chaterlea25 on 25.07. 2010 19:16
Hi JohnH
In the last couple of weeks I fitted a top end together and didnt bother with the tool,
I slackened off the tappet adjusters and put a little grease in the cups
as I lowered the box I was able to engage the pushrods in the rocker cups using a small torch and a long thin screwdriver
I found this easier than using the comb and you dont upset the gaskets/or goo!!!!

My 2 cent opinion again
John O R
Title: Re: A10 Pushrod alignment tool
Post by: taroha10 on 25.07. 2010 21:04
Hi John H,
Just in case you do want a pushrod comb,I saw one under the counter at Rockerbox Motorcycles Nr Farnham Surrey last week.I guess that they are still made by someone as it looked new.
Good luck howrever you sort it.
Taroha10
Title: Re: A10 Pushrod alignment tool
Post by: JohnH on 26.07. 2010 07:42
Thanks to John O R and Taroha10. I get Real Classics magazine and Humbernut is currently running a series on an A10 engine and power train. Seems really good and I noted in the section on the head that he was using a long thin screwdriver and makes exactly the point as John OR. I'll try to pop over to Rockerbox Motorcycles Taroha10 - I think I'll get one of the tools (while they're available!) and when I have it I'll try to put up a sketch of it for those who might like to make one ..... and for posterity!

Many thanks.
John
Title: Re: A10 Pushrod alignment tool
Post by: Brian on 26.07. 2010 07:47
Their easily available, just about any english bike shop has them or there are lots on evil-bay.


http://cgi.ebay.com.au/BSA-A7-BSA-A10-Push-Rod-Aligning-Comb-Tool-P179-/190419969510?cmd=ViewItem&pt=UK_Motorcycle_Parts&hash=item2c55ea25e6
Title: Re: A10 Pushrod alignment tool
Post by: a10gf on 26.07. 2010 09:35
Home made tools, see http://www.a7a10.net/forum/index.php/topic,368.0.html
Use search, there are lot's of topics about the pushrod tool.
Title: Re: A10 Pushrod alignment tool
Post by: JohnH on 26.07. 2010 10:23
Thanks for the help. I just got one from the eBay source described by Brian. Will try to post a sketch when I get the chance.

Thanks for all the help.
John
Title: Re: A10 Pushrod alignment tool
Post by: A10Boy on 26.07. 2010 11:23
I always use the screwdriver method. That tool is a pain in the arris, you end up with your carefully placed hylomar all messed up.
Title: Re: A10 Pushrod alignment tool
Post by: JohnH on 26.07. 2010 11:35
Thanks A10Boy - I plan to try the long screwdriver method first but I've learned from bitter experience that it's always a good idea to have a fallback position .... this is it - and I'll enjoy putting together a sketch of it so that others can put a fallback in place too!

Cheers
Title: Re: A10 Pushrod alignment tool
Post by: BSA_54A10 on 26.07. 2010 12:06
Originally I used a comb cut using the proper tool as a template from the stiff plastic on shirt boxes.
This was good because it would bend out of the way when you had the rockers nearly all the way.
Not I use some long right angled , normally closed tweezers .
This way I remove the tappet adjusters , hold the pushrod in position and replace the adjusters.
It dose take a little longer but as noted previously dose not mess up the joint faces ( & use Hylomar too )
Title: Re: A10 Pushrod alignment tool
Post by: A10Boy on 26.07. 2010 12:35
Those combs are only about 9 pence...
Title: Re: A10 Pushrod alignment tool
Post by: JohnH on 26.07. 2010 12:48
I like the sound of your method BSA_54A10.
 
So you're seating the rockerbox housing after removing the valve ajusters and you're then using your long right angled tweezers to hold each pushrod in place while you refix the valve adjuster, winding it in to seating in the pushrod top cup. Then presumably repeat for each pushrod. That sounds as though it overcomes the problem of messing up the rockerbox sealant and ensures that each pushrod is individually located - it has to beat trying to locate all 4 simultaneously. What do the other guys who have responded think?

I suspect you're right A10Boy - the combs do cost about 9 pence ..... if you make it yourself. But you do need a template or drawing to do that .... don't you?

Thanks for all the really good suggestions and thoughts.
John
Title: Re: A10 Pushrod alignment tool
Post by: bsa-bill on 26.07. 2010 12:57
Yes Trev, John I use a long piece of wire with a hook at the end, I don't take the tappet adjuster right out but slacken them right off, then fish each rod into it's respective cup.
Sounds fiddly but as you say beats having your sparingly placed goo wiped off and redistributed over  fingers , comb and every where in between
Title: Re: A10 Pushrod alignment tool
Post by: JohnH on 26.07. 2010 13:05
Nice! - I love it!

Many thanks,
John
Title: Re: A10 Pushrod alignment tool
Post by: muskrat on 26.07. 2010 14:14
I have another method. I put sealer on the underside of the gasket and place on head and sealer on the rocker box. Careful removal of the comb doesn't upset the sealer. But it still bl@@dy leaks. As I dont use the springs on the rocker shafts (shimmed instead) the rockers just flop down. I use elastic bands under the tappets and stretched across to the opposite top cover stud. This holds the cups down. When the box is lowered to with in 1/4" from the head I drop in the two bolts for the comb to sit against, drop it another 1/8" and all the rods are in their cups, the rubber bands keep pressure on them, remove comb, tighten bolts to bring the box home. I have used this method with bent wire instead of the comb as well.
Cheers
















Title: Re: A10 Pushrod alignment tool
Post by: JohnH on 26.07. 2010 15:50
And yet another good reply - thanks Muskrat.

That's a very pretty bike you've got there - looks as though it can go a bit!

John
Title: Re: A10 Pushrod alignment tool
Post by: iansoady on 26.07. 2010 16:37
I haven't had the pleasure of doing this on the A10 yet but what always worked on the Norton Commando I had for 20 years was to prop the head 1/2" or so clear of the barrels (the Norton has the rocker box integral with the head) then use the long screwdriver to get the pushrod ends into the rockers whilst gently waggling the rocker to make sure it was seated. Obviously this means the valve end of the rockers is a long way from contact but by gently lowering the head everything lines up.

The rocker covers on the Norton were much smaller than the BSA ones so I would have thought a similar procedure may work. I can see that the comb affair could cause problems with the gasket and any sealant used.
Title: Re: A10 Pushrod alignment tool
Post by: JohnH on 26.07. 2010 16:53
Yes - it looks as if the gasket goo could get into a right royal state to me - confirmed by several folks on this forum. I really like the sound of the tweezer solution though.

John