Huffing, Puffing, Wheezing and Timing marks

[bsa-bill]

Amazed and puzzled at the wheezing noises coming from the Rocket Gold Flash when turned slowly over, and this with plugs out so not valves letting in air or out, do they all do this, no my flash doesn't, I decided it must be breather related and as I needed to remove the timing cover to disconnect the dynamo drive to see if it would motor ( wasn't charging, turned out brushes stuck).
with the timing cover off there is no wheezing, can't see much wrong though, cork is right thickness, peg is engaged, top hat looks the same as others I've looked at images of.
I've squirted cleaner up the air escape route and blown air through it with my compressor, could it just be due to the engine being tight?

Now whilst I was in there I noticed there is one dash on the idler pinion but two dots, one is deeper than the other and they are one tooth apart, I have used the deeper one when setting up as I did not really notice the other (I've been to Specsaver since).
So it would be a great help if anyone with an engine apart or has a spare idler pinion could tell me how many teeth there are between the dash and the dot, both dash and dot are in the valley between teeth
There are 20 full teeth between the dash and deeper dot on mine, and 21 between dash and other dot

All the best - Bill

[wilko]

Has it wetsumped? Drain it and see.

[bsa-bill]

Thanks Wilko - No it's not wetsumped - it might be asthmatic but it's not incontinent

[trevinoz]

Bill,
          20 is correct.
     Trev.

[dpaddock]

The "wheezing" noise sounds about right; remember, the engine's expelling forty cubic inches each downstroke. You have good hearing!

Not sure about your timing marks question. Can you post a pic or two?

David

[chaterlea25]

Hello Again Bill,
Just so as you are aware, after setting up the timing marks, then rotating the engine it takes umpteen turns before they line up again
This is because the idler has an uneven number of teeth, its called a "hunting tooth" setup

HTH
John O R

[Retired Fireman]

Hi Bill, what number cam has your bike got in it? and did BSA make different idler pinion marks for the different grinds of cams?? e.g. Triumph inlet cams had 2 marks one for the thunderbird cam and the other for Tigers Trophys and Bonnies. Over the years some one might have replaced either the cam or the idler pinion and the dots are incorrect for the combination of what you have. The answer is you have to fit a degree disc to the crank along with a dial indicator to the vales set tappets at 020", establish TDC set a pointer on the disc ot TDC and then observe what you actual vavle timing is doing. A side benifit is the different cam grinds used different tappet settings so if nothing else you can prove that your cam is a 334 356 or 357 or something special someones ground then use the correct settings. To mount a disc to the timing side find an old worm drive oil pump drive and braze a 3" piece of 1/2" threaded rod onto the outer end and screw on 2 nuts and washers to mount the disc clear of the engine held between the inner nut/washer and tighten the outer nut washer to hold it to the shaft. There is always a couple of threads hanging out of the existing crank oil pump pinion to screw this on the timing side of the crank (left hand thread!), then get a timing cover screw and fashion a piece of coathangar wire or simular with a washer on the outside and fix this to a screw hole to hold in position then bend the point to 0 deg at TDC on the disc. You can also use this to check your ign timing acurately using a strobe light, don't forget to check both sides to see if they are the same. Hope this helps.

[Retired Fireman]

Whoops didn't say your valve timing might be slightly out therefor the the breathing might be out, I once found an repro cam that was ground wrong and the valve timing was everywere but were it should have been!

[trevinoz]

Fireman,
              As far as I know there was only one pinion made.
Sometimes the early long stroke pinions get fitted by mistake or ignorance.
They look exactly the same but have different timing marks.
Trev.

[Retired Fireman]

Thanks Trev wasn't sure now I know, my A10 sounds like it's got emphasima when I turn it over slowly but I would still check the valve timing with a disc. I take nothing for granted in these bikes until I have proven everthing is correct.

[bsa-bill]

Thanks Guys, Trev, 20 is what I wanted to know and where I had it set, 21 would mean the marks would not be entirely lined up although close.
John I think it takes around 78 to 80 turns to get the marks lined up again, easier when the inner cover is off to set the cam pinion so the timing mark is at 4 o clock (TDC) slip the pinion off and slowly turn the crank to get the dots and dashs lined up,
Retired Fireman - only one idler pinion listed and the cam is 356 (I have a 357, maybe try it someday when the lump is free and easy), it was that fact that there are two dots on the crank pinion that I wanted to clarify, looks like either Bert at BSA miscounted first time he counted the teeth or a PO had illusions of being a top tuner.
David my wife says my hearing is pathetic and I don't want her to think any different , the wheezing is pretty loud but can't be anything other than coming from the piston forcing air out through the breather, I've checked about everything apart from the exit hole behind the primary chain case could be a PO has stuffed something up there that is restricting airflow, need to look at that and the clearance between the tophat breather and the circular potion of the outer timing cover.

once again thanks for info - Bill

[RichardL]

This "hunting tooth" matter has come up before and I thought it pretty interesting, enough so to try the "maths" (bowing to the Brit spelling). 98 turns is the number and the post can be found in this thread:

http://www.a7a10.net/forum/index.php/topic,789.msg5039.html#msg5039


Richard L.