Author Topic: bsa a10 650..the problem child !  (Read 12743 times)

Offline lawnmowerman

  • Resident Legend
  • *****
  • Join Date: Dec 2009
  • Posts: 602
  • Karma: 8
  • 1959 Super Rocket. Kent, England
Re: bsa a10 650..the problem child !
« Reply #30 on: 14.06. 2010 14:23 »
Hi Andy
I had a similar problem on my SR which was rebuilt by the PO. It would run for a few miles and cut, miss and sometimes backfire. I tried new plugs and leads, cleaned fuel filters but the problem persisted. In desperation I tried turning both fuel taps on and it never missed a beat. I checked the taps and the rubbers have spread after use and were severly restricting fuel flow. I will fit some better taps soon - possibly central heating oil full flow ball types.

Just a thought but a run with both taps on if you have not already tried it is an easy check before you pull it apart.

Jim
1959 A10 SR
1938 Wolseley 14/60
1955 Ferguson TEF20 tractor
1965 Ferguson 135 tractor
1952 Matchless G80 rigid
1960 BMW R60
1954 Matchless G80S
1955 Ariel 500 VH
1951 Sunbeam S7DL
1960 Matchless G12 with Watsonian Monza
......and loads of lawnmowers

Too old to Rock and Roll but too young to die  (Jethro Tull 1976)

Online RichardL

  • Outside Chicago, IL
  • Wise & Enlightened
  • *
  • Join Date: Nov 2007
  • Posts: 4979
  • Karma: 48
Re: bsa a10 650..the problem child !
« Reply #31 on: 14.06. 2010 14:41 »
Markus,

I suppose I could have hidden my ignorance by saying "iron-based". That would have covered it. Now, you force me to go to the web to try to see the machinery used in centrifugal casting. Danged information superhighway! If it turns out to be a way to find actors to fill roles as astronauts I'm going to be very disappointed.

Richard L.
Plan on signing up for the world-wide 2017 DISTINGUISHED GENTLEMAN'S RIDE on September 30, 2018. Watch website at https://www.gentlemansride.com for details.

Offline A10Boy

  • Wise & Enlightened
  • *
  • Join Date: Jun 2008
  • Posts: 1075
  • Karma: 11
  • Solihull, Near Birmingham England.
Re: bsa a10 650..the problem child !
« Reply #32 on: 14.06. 2010 16:01 »
I cant see thats its poor oiling to the valves. but what do i know. One thing you can do is remove the oil tank cap and put your finger over the oil return jet for a few seconds, that should oil the valves up.

What exactly did the electronic ignition replace, was it a full system, you now have no mag or what?

When it stops does it seem over heated?

Are you using an air filter, if so remove it and try it without.
Regards

Andy

1960 A10 - Black Golden Flash
Plus
1974 Kawasaki Z1a
Yam XJR 1300

Offline a10sausage

  • Moving Up
  • **
  • Join Date: Jan 2009
  • Posts: 98
  • Karma: 0
  • 58 flash
Re: bsa a10 650..the problem child !
« Reply #33 on: 14.06. 2010 16:17 »
wow thanks everybody for the help...muskrat your advice about opening the valve clearances a few thou more has got to be worth a go before i take the cylinder head off ..just to let the rest of the forum know that i am running ngk b6hs plugs and the carb is set up as standard via the book for a 58 a10..i have the valve clearances inlet 0.010 exhaust 0.013 hope this helps oh and pushrods have only done 2k from new..cheers andy
1959 bsa bantam d1
1956 ariel huntmaster
1922 triumph model h
1930 sunbeam model 8
1936 bsa q21 500 bluestar
1939 velocette mac
1975 honda cb750
2013 victory vegas

Offline a10sausage

  • Moving Up
  • **
  • Join Date: Jan 2009
  • Posts: 98
  • Karma: 0
  • 58 flash
Re: bsa a10 650..the problem child !
« Reply #34 on: 14.06. 2010 16:20 »
oh no...haynes manual says 0.016 for 58 flash is this correct
1959 bsa bantam d1
1956 ariel huntmaster
1922 triumph model h
1930 sunbeam model 8
1936 bsa q21 500 bluestar
1939 velocette mac
1975 honda cb750
2013 victory vegas

Offline a10sausage

  • Moving Up
  • **
  • Join Date: Jan 2009
  • Posts: 98
  • Karma: 0
  • 58 flash
1959 bsa bantam d1
1956 ariel huntmaster
1922 triumph model h
1930 sunbeam model 8
1936 bsa q21 500 bluestar
1939 velocette mac
1975 honda cb750
2013 victory vegas

Offline A10Boy

  • Wise & Enlightened
  • *
  • Join Date: Jun 2008
  • Posts: 1075
  • Karma: 11
  • Solihull, Near Birmingham England.
Re: bsa a10 650..the problem child !
« Reply #36 on: 14.06. 2010 19:16 »
Dont worry, my iron A10 is 10 and 12, and no probs.

Bigger clearances were given for hard use but 10 / 12 is OK for normal use. That certainly wont stop the engine.  *conf*
Regards

Andy

1960 A10 - Black Golden Flash
Plus
1974 Kawasaki Z1a
Yam XJR 1300

Offline MG

  • Resident Legend
  • *****
  • Join Date: Dec 2009
  • Posts: 949
  • Karma: 23
Re: bsa a10 650..the problem child !
« Reply #37 on: 14.06. 2010 19:41 »
Yep, I'm running mine on 10 thou exhaust and 8 thou inlet and it runs happily even when thrashed, although the engine is running on 9:1 CR.

The plot thickens, I'm afraid the sticking valve is the most likely culprit.


Quote
If it turns out to be a way to find actors to fill roles as astronauts I'm going to be very disappointed.

*lol*
The last one to barf gets to play Neil Armstrong.
1955 A7 Shooting Star
1956 A10 Golden Flash
1961 Matchless G12 CSR

www.histo-tech.at - Restoration, Repairs, Racing

Austria

Online trevinoz

  • Newcastle, N.S.W. Australia.
  • Wise & Enlightened
  • *
  • Join Date: Jul 2006
  • Posts: 2869
  • Karma: 67
Re: bsa a10 650..the problem child !
« Reply #38 on: 14.06. 2010 23:12 »
.016" is for 334 camshaft.
    Trev.

Offline muskrat

  • Global Moderator
  • Wise & Enlightened
  • **
  • Join Date: Jul 2009
  • Posts: 8098
  • Karma: 106
  • Lake Conjola NSW Oz
    • Shoalhaven Classic Motorcycle Club Inc
Re: bsa a10 650..the problem child !
« Reply #39 on: 15.06. 2010 10:21 »
Dont worry, my iron A10 is 10 and 12, and no probs.

Bigger clearances were given for hard use but 10 / 12 is OK for normal use. That certainly wont stop the engine.  *conf*
It will if it gets hot enough.
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, .
Australia
Muskys Plunger A7

Offline A10Boy

  • Wise & Enlightened
  • *
  • Join Date: Jun 2008
  • Posts: 1075
  • Karma: 11
  • Solihull, Near Birmingham England.
Re: bsa a10 650..the problem child !
« Reply #40 on: 15.06. 2010 11:43 »
10 / 12 is fine, I've had mine well hot on a long run. I wouldn't risk any damage. Some people use 8 / 10 without problems.

Thanks to Trev for the info table
Quote
The valve clearances are determined by the camshaft used.
67-334   .010/.016
67-356   .008/.008  Later changed to .008/.010
67-357   .008/.010,  Max power - .010/.012
Trev.
Regards

Andy

1960 A10 - Black Golden Flash
Plus
1974 Kawasaki Z1a
Yam XJR 1300

Offline olev

  • Brisbane, Australia
  • Valued Contributor
  • ****
  • Join Date: Sep 2008
  • Posts: 487
  • Karma: 3
Re: bsa a10 650..the problem child !
« Reply #41 on: 15.06. 2010 13:13 »
I bought a reconditioned iron head with oversize toyota valves some time back.
The gent who sold it to me got in contact later saying he was having trouble on 2 other bikes due to the bronze or brass valve guides he was putting in. Apparently they stuck when the engine got hot.
He changed the guides and had no further trouble.
So I'm not sure whether a dud batch came out of England a couple of years ago.
This guy owns an engine reconditioning shop and has A10s so I assume he knows what he's about.
I'll be keeping a close eye on mine if I ever get the damned thing finished.

Offline a10sausage

  • Moving Up
  • **
  • Join Date: Jan 2009
  • Posts: 98
  • Karma: 0
  • 58 flash
Re: bsa a10 650..the problem child !
« Reply #42 on: 15.06. 2010 21:09 »
hi folks i was talking the problem over with a friend and he put forward the idea that if it was a sticking exhaust valve the bike would continue to run on one cylinder..is this correct...sounds feasable to me!
1959 bsa bantam d1
1956 ariel huntmaster
1922 triumph model h
1930 sunbeam model 8
1936 bsa q21 500 bluestar
1939 velocette mac
1975 honda cb750
2013 victory vegas

Offline muskrat

  • Global Moderator
  • Wise & Enlightened
  • **
  • Join Date: Jul 2009
  • Posts: 8098
  • Karma: 106
  • Lake Conjola NSW Oz
    • Shoalhaven Classic Motorcycle Club Inc
Re: bsa a10 650..the problem child !
« Reply #43 on: 15.06. 2010 21:58 »
That is true, I recently bent both timing side valves and rode home (2 miles) on one lung. Seems unlikley, but not imposable, for both ex valves to stick. Have you tried larger clearances yet.
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, .
Australia
Muskys Plunger A7

Offline brackenfel

  • Valued Contributor
  • ****
  • Join Date: Jan 2010
  • Posts: 271
  • Karma: 2
  • Adrian - Bristol UK
Re: bsa a10 650..the problem child !
« Reply #44 on: 16.06. 2010 13:46 »
Not discounting the idea of a sticky valve I'll go with what Jim (lawnmowerman) suggested..

My Velo Viper has 2 fuel taps & both appear to work well when the tank is full. However when the level drops a little I get odd starvation problems if only one is open even when the fuel level is well above the "reserve" line, cured by opening both taps!.
It appears to be an odd vacuum type condition for some reason best known to the bike. I know which tap it is but no idea why...

Just a thought......
1961 A10 650 Golden Flash - Blue
1954 BSA B33
Velocette Viper
Laverda 750 SF1
Kawasaki W650
Buell XB9S
Ariel 350NH & Matchless G3LS in bits...