The BSA A7-A10 Forum

Technical => A7 & A10 Engine => Topic started by: Gerry on 08.10. 2014 12:16

Title: A10 valve timing
Post by: Gerry on 08.10. 2014 12:16
Hi Guys, Thanks a million for this info' but.....my pinion which I just rushed out and checked seems to be correct with 20 teeth between the two marks and is stamped 67-336!!! So where do I go now. I'm sure that I have got the number of degrees before TDC as I have checked it a zillion times and all times came out the same. Check out the pics' of my idler gear. Cheers. Gerry
Title: Re: A10 valve timing
Post by: beezermacc on 08.10. 2014 16:48
All the pinions are different, not just the idle pinion.
Title: Re: A10 valve timing
Post by: Gerry on 09.10. 2014 01:26
Hi Mac, OK I'll check them also as against the drawing I downloaded off here. Cheers. Gerry
Title: Re: A10 valve timing
Post by: Gerry on 09.10. 2014 04:37
OK checked the crankshaft pinion........looks like I have the A7 long stroke pinion!!! The dot is just to the left of the keyway. So maybe I might just get it right eh?
Wish me luck. Gerry
Title: Re: A10 valve timing
Post by: Gerry on 09.10. 2014 04:40
If I align the idler pinion mark with the third tooth to the left of the present mark on the crank shaft pinion will that do the trick?
Title: Re: A10 valve timing
Post by: Gerry on 09.10. 2014 07:57
Hi all, I have another problem.....My Hains manual says that valve timing should be as follows:- Inlet opens at 30 degrees BTDC and closes at 70 degrees ABDC. Exhaust opens at 65 degrees before BDC and closes at 25 degrees after TDC. While a friend looked the timing up in his charts and told me that they should be as follows 42 degrees, 62 degrees, 67 degrees and 37 degrees respectively for a 59 Gold Flash. Any one know which is correct? Cheers. Gerry
Title: Re: A10 valve timing
Post by: Brian on 09.10. 2014 08:05
Gerry the 30/70 figure is for the 334 cam, if yours has the 356 fitted its the 42/62.

The best way for you is to set it up with the degree disc. If you had the correct gears it would be right so one or more of your gears must be wrong.
Title: Re: A10 valve timing
Post by: beezermacc on 09.10. 2014 09:18
If we're not careful we're going to get confused. Longstroke cams and gears which were very distinctive with the cam looking more like an A65 cam with narrow lobes. The camshaft is not interchangeable with the shortstroke camshaft. The gears are physically the same except for the stub on the cam gear which times the top hat breather. But the timing dots are in different places. See the tech tips section on the cheshirebsa website.

The shortstroke A7 and A10 from 1950 usually had 67-334/356/357 cams, depending on the model. The part number is usually stamped on the end of the cam.
Title: Re: A10 valve timing
Post by: Gerry on 09.10. 2014 10:54
Sorry fellas, maybe should have started a new thread re the short stroke A10.Will do so now, but the information supplied here by you great fellas has really showed up my problem. Will start a new thread with any progress I make. Cheers. Gerry
Title: Re: A10 valve timing
Post by: muskrat on 09.10. 2014 20:36
G'day Gerry. My book says.
Long stroke A7 = 24, 65, 60, 21.5. Both tappets at 15thou, ign timing at 5/16" or 3/8" for star Twin.
Short stroke A7 '50-'54 = 30, 70, 65, 25. Both tappets 10thou,             "                     
Short Stroke A7 ST '50-'54 = 42, 62, 67, 37. Tappets 8 & 12thou.                                 "
Cheers
Title: Re: A10 valve timing
Post by: duTch on 09.10. 2014 23:04

  *conf*
   Yo, Gerry I'm getting confused if this is the same engine with the worn lifters, or a longstroke motor. ..?
Title: A10 valve timing
Post by: Gerry on 10.10. 2014 00:55
Hi fellas, Muskrat I have a Haines workshop manual which states the valve timing for the A10 to be - in' opens 30 deg's before TDC. In' closes 70 deg's after BDC. Ex' opens 65 deg's before BDC and closes 25 deg's after TDC. Now I'm told by a friend (who gave me the followers) that the valve timing should be as follows - In' opens 42 deg's before TDC closes 62 deg's after BDC. Ex' opens 67 deg's before BDC and closes 37 deg's after TDC. Now I have been told the later figures apply to engines after DA10 1647 so am going to check whether these figures apply to mine. If so and my crank shaft pinion is one tooth out (A7 pinion) then I recon' it just might come good if I shift the idler pinion mark one tooth to the left of the mark on the engine pinion. What say you? Would this give me the symptoms I'm getting? Cheers. Gerry
Title: Re: A10 valve timing
Post by: Brian on 10.10. 2014 01:17
Gerry ignore any information you have been given about engine numbers etc. Its the camshaft that matters, if you definitely have a 356 cam fitted then the 42/62 figure is correct.

The camshaft will have the number 356 stamped in the end of it.
Title: Re: A10 valve timing
Post by: Gerry on 10.10. 2014 01:48
Hi Brian, Yes the cam shaft is marked 356. The cam pinion number of teeth between the timing mark and the keyway is correct at 15 teeth clockwise. The idler pinion is correct at 21 teeth. But the engine pinion is one tooth to the left (anticlockwise) of the keyway which denotes it as A7 I believe, which gives me the wrong valve timing. Should be two teeth to the left for the A10. Cheers. Gerry
Title: Re: A10 valve timing
Post by: Gerry on 10.10. 2014 01:52
My engine number is DA10 4911 So I believe the later valve timing applies. Cheers again. Gerry
Title: Re: A10 valve timing
Post by: muskrat on 10.10. 2014 11:45
And definitely don't take the haynes manual as anything to go by. In their book they rebuilt one A10, an iron head. Our A's came in numerous models and variants. Even the bike on their cover has the wrong front brake ('68 A65).
Cheers
Title: Re: A10 valve timing
Post by: Gerry on 11.10. 2014 08:27
Hi Muskrat, Yes I'm beginning to realise that. The Haines Manual also doesn't give any mention of packing the dynamo chain and cogs with grease. Not that I could find anyway. Got the Super Rocket twin carb' head on yesterday and today fitted the rocker box........took me about 15 mins' whooohooo, getting bloody good at it. Too buggered to do any more and my old back is killing me. lol Tomorrow set the tappets, fit the tank and see if I can get it running and oil the floor with the timing cover off. Primary cover off so I can check ignition timing. Wish me luck fellas. Cheers. Gerry (Anyone see the Adelaide Advertiser paper today with the Great White chewing on a seal pup?) Great place Australia....more deadlies than anywhere else in the World.
Title: Re: A10 valve timing
Post by: muskrat on 11.10. 2014 12:08
Best of luck mate. Have you made provision to balance the carbs. a small 1/32" hole into each manifold opened up to 3/16" to glue a hose tail into. When not hooked up to gauges link together.
King Browns guard my bottom shed near the creek.
Cheers
Title: Re: A10 valve timing
Post by: duTch on 11.10. 2014 21:40

 Good luck with out Gerry, hope it goes like a rocket. ...!
Title: Re: A10 valve timing
Post by: Gerry on 12.10. 2014 00:54
Hi Muskrat, Dutch, 10am....just got out of bed...love this retirement game!! No Muskrat only got a single carb' and manifold for the moment. Got enough troubles as it is without giving myself any more eh? lol. Will use a separate 12 volt battery to check the ignition timing and this time check I have the clamp the right way round on the HT lead dooh!! Cheers Gerry
Title: Re: A10 valve timing
Post by: Gerry on 14.10. 2014 12:12
OK Guys.....Th latest is.......thought I'd adjust the primary a tad....top adjuster nut stripped!!!! Made a new one out of stainless hex' bar........kicked it over slowly to check valves were not coil bound and double check valve timing.......kickstart spring broke!! Went and got a new one and fitted it, refilled the gearbox and tried the kickstart and BANG out of the exhaust.....checked the ignition timing manually and all ok so changed the leads over and tried again.....kicked me back a few times so rechecked the ignition timing and seemed ok, the bloody advance was stuck in the fully advanced position. Gave it a few twists and put it into retard mode.....kicked it again and away she went, so much better than ever before. So packed the dynamo chain with grease, fitted a new gasket to the timing cover and refitted it. Had enough for today so still haven't checked the ignition timing with the strobe as yet, but will do so tomorrow and hopefully button up the primary cover and take her for a ride......if nothing else gives me trouble. lol Wish me luck fellas. Cheers. Gerry
Title: Re: A10 valve timing
Post by: Topdad on 14.10. 2014 14:05
Gerry, you're certainly due some particularly for sticking at it , very best of luck and enjoy tomorrow, BOBh
Title: Re: A10 valve timing
Post by: muskrat on 14.10. 2014 20:12
Good onya Gerry. Once your out on the road with her it will all fade away.
Cheers
Title: Re: A10 valve timing
Post by: Gerry on 22.10. 2014 04:11
Hi Guys, No news on how she goes as yet......too bloody hot out there, over 35 degrees and I aint going out without the leathers either. Only got 4 days of rego' left so got to do it before that ends...Cheers. Gerry
Title: Re: A10 valve timing
Post by: Gerry on 22.10. 2014 09:02
Hi Guys, OK bit the bullet and took her out for a short ride this evening just to see how she goes. Only problem I have now is she still misses on the left hand cylinder after slowing down and on opening up again half the time but not every time. Plus an oil leak from the primary cover which I oiled with transmission oil and greased the gasket before putting it back last time. So will remove it and use gasket cement (Locktite gasket eliminator). Anyone know if the A7 longstroke engine timing pinion, which is what I have on the bike, is the same as the A10 timing pinion other than the timing mark being different? Cheers. Gerry
Title: Re: A10 valve timing
Post by: trevinoz on 22.10. 2014 21:01
Hi Gerry, the pinion is the same except for the timing mark.
Title: Re: A10 valve timing
Post by: Gerry on 25.10. 2014 05:29
Hi Trev, OK thanks fella, it is appreciated.....at least now I know timing is correct and other than the missing on the left hand cylinder when ticking over occasionally and when opening up all seems ok. Will do another compression test on both cylinders alternately. Run on right cyl' and check the left and vice versa on the right. Might have to bore and new pistons if any appreciable difference between cylinders. Cheers. Gerry
Title: Re: A10 valve timing
Post by: muskrat on 25.10. 2014 11:11
Don't be lazy. Take out both plugs, test one at a time with the throttle wide open and about 10 kicks.
Cheers
Title: Re: A10 valve timing
Post by: Gerry on 25.10. 2014 14:33
Hi Muskrat, That's going to kill my poor old back fella!! Even with the plugs out. lol Will give it a go though your the master mate. Cheers. Gerry