Author Topic: A10 valve timing  (Read 3006 times)

Offline Gerry

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A10 valve timing
« 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

Offline beezermacc

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Re: A10 valve timing
« Reply #1 on: 08.10. 2014 16:48 »
All the pinions are different, not just the idle pinion.
Priory Magnetos Ltd - A10 spares, magneto and dynamo refurbs. www.priorymagnetos.co.uk

Offline Gerry

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Re: A10 valve timing
« Reply #2 on: 09.10. 2014 01:26 »
Hi Mac, OK I'll check them also as against the drawing I downloaded off here. Cheers. Gerry

Offline Gerry

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Re: A10 valve timing
« Reply #3 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

Offline Gerry

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Re: A10 valve timing
« Reply #4 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?

Offline Gerry

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Re: A10 valve timing
« Reply #5 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

Online Brian

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Re: A10 valve timing
« Reply #6 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.

Offline beezermacc

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Re: A10 valve timing
« Reply #7 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.
Priory Magnetos Ltd - A10 spares, magneto and dynamo refurbs. www.priorymagnetos.co.uk

Offline Gerry

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Re: A10 valve timing
« Reply #8 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

Online muskrat

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Re: A10 valve timing
« Reply #9 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
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
Muskys Plunger A7

Offline duTch

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Re: A10 valve timing
« Reply #10 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. ..?
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Offline Gerry

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A10 valve timing
« Reply #11 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

Online Brian

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Re: A10 valve timing
« Reply #12 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.

Offline Gerry

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Re: A10 valve timing
« Reply #13 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

Offline Gerry

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Re: A10 valve timing
« Reply #14 on: 10.10. 2014 01:52 »
My engine number is DA10 4911 So I believe the later valve timing applies. Cheers again. Gerry