Author Topic: no power  (Read 3030 times)

Offline Frenchy

  • A's Best Friend
  • ***
  • Join Date: Oct 2009
  • Posts: 66
  • Karma: 0
  • 1957 A7
no power
« on: 25.08. 2010 15:09 »
I finally...  FINALLY... heard some life from my A7.  But there are some problems.  The biggest of which is that there's absolutely no power.  It'll take off in first gear, but at no more than 5 mph.  Has anyone else experienced this? 

Other problems include a wicked oil leak behind the primary.  I've got a gasket set, though, so I might be able to track that one down myself.  Also, the rear wheel spins true, but is at a bit of an angle.  I'll post a picture later.  It's like the swing arm might be bent. 

Any thoughts?  Or other posts that might address any of this?

1957 A7 bobber, swing arm
Columbus, Ohio, US

Offline lawnmowerman

  • Resident Legend
  • *****
  • Join Date: Dec 2009
  • Posts: 614
  • Karma: 8
  • 1959 Super Rocket. Kent, England
Re: no power
« Reply #1 on: 25.08. 2010 15:31 »
Possibly a blocked main jet if it has been standing for a while - does it rev up ok in neutral?
As far as wheel alignment goes - I remember a post a while ago from LJ where he made up a wheel alignment jig from a piece of timber and some studding.
Keep us posted - you will find all the advice and information you need on this forum.

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)

Offline a101960

  • Wise & Enlightened
  • *
  • Join Date: Sep 2007
  • Posts: 1040
  • Karma: 12
  • BSA RGS BSA C12
Re: no power
« Reply #2 on: 25.08. 2010 15:52 »
Might be that the needle clip is weak and is not gripping the needle. In which case the needle will not lift. Put your finger into the carb and operate the twist grip. Can you feel the needle lifting? If the engine revs in neutral you might have a slipping clutch, or binding brakes.

John

Offline beezalex

  • North Carolina, USA
  • Valued Contributor
  • ****
  • Join Date: Jan 2008
  • Posts: 374
  • Karma: 4
Re: no power
« Reply #3 on: 25.08. 2010 16:13 »
Could be a whole lot of things.

Does it smoke or pop/misfire?  Can you open the throttle, or does it die?  Is it running on both cylinders?  Does it rev at all?  Clutch slipping?  Is it blowing oil out the breather?

More specific info on symptoms would help.
Alex

Too many BSA's


Online bsa-bill

  • Wise & Enlightened
  • *
  • Join Date: Mar 2006
  • Posts: 5456
  • Karma: 62
Re: no power
« Reply #4 on: 25.08. 2010 18:14 »
A wicked leak behind the primary ????
not to many places behind the primary that should produce a wicked leak - other than wet sumping, in which case there just might be a connection to your lack of power, tell us more about the oil that is leaking is it - black (engine) - oil coloured  (primary), smells metallic ( gearbox)
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Offline a10gf

  • Wise & Enlightened
  • *
  • Join Date: Sep 2006
  • Posts: 2802
  • Karma: 42
  • West Coast, Norway & Alpes Maritimes, France
    • A10 GF
Re: no power
« Reply #5 on: 25.08. 2010 18:53 »
Quote
I finally...  FINALLY... heard some life from my A7.
*clap* Congrats, good work. You'll sort out the rest over time, and learn a lot in the process. Maybe start with a check of magneto + timing, valve clearances & carb.

A10 GF '53 My A10 website
"Success only gets you a ticket to a much more difficult task"

Offline Frenchy

  • A's Best Friend
  • ***
  • Join Date: Oct 2009
  • Posts: 66
  • Karma: 0
  • 1957 A7
Re: no power
« Reply #6 on: 25.08. 2010 22:34 »
Hmm, what does a slipping clutch feel like?  I don't really feel anything out of the ordinary...  'Cept for no umph.

I took some photos and will put a link up tonight with some more specifics.  Thanks again for everyone's expertise!
1957 A7 bobber, swing arm
Columbus, Ohio, US

Offline a10gf

  • Wise & Enlightened
  • *
  • Join Date: Sep 2006
  • Posts: 2802
  • Karma: 42
  • West Coast, Norway & Alpes Maritimes, France
    • A10 GF
Re: no power
« Reply #7 on: 25.08. 2010 23:03 »
Quote
what does a slipping clutch feel like?
lots of revs and no go

A10 GF '53 My A10 website
"Success only gets you a ticket to a much more difficult task"

Offline cus

  • Valued Contributor
  • ****
  • Join Date: Jun 2009
  • Posts: 305
  • Karma: 4
Re: no power
« Reply #8 on: 25.08. 2010 23:56 »
G'day Frenchy,
This is going to sound a bit obvious, but are you aware that gear selection is one up the rest down,
you might be taking off in 4th. Just thought I'd mention this because you might only be
familiar with more modern bikes!

Cus
56 G/Flash project

Offline Frenchy

  • A's Best Friend
  • ***
  • Join Date: Oct 2009
  • Posts: 66
  • Karma: 0
  • 1957 A7
Re: no power
« Reply #9 on: 26.08. 2010 00:19 »
One up, three down.  Please feel free to point out the obvious, I'm new at this!

Yeah, I've got lots of rev and no go.  Dang.  How much of a task is repairing the clutch?  Financially and otherwise.  I've got some guys coming over Friday to help out with my timing and to work on the oil leak.  Maybe it's as simple as that.  The Haynes lists both clutch and timing as a possible source of "no go."
1957 A7 bobber, swing arm
Columbus, Ohio, US

Offline cus

  • Valued Contributor
  • ****
  • Join Date: Jun 2009
  • Posts: 305
  • Karma: 4
Re: no power
« Reply #10 on: 26.08. 2010 00:43 »
Frenchy,
Take your primary case cover off, you'll see if it slips on takeoff.
Take off the pressure plate, pull all your plates out, wash with petrol,
put all back. Make sure you get the press. plate spinning even with lever
pulled in, & before you put the cover on experiment with how far down you
screw the springs in. Also, while the springs are out, check they are all
the same length, you may need new ones,

Cus
56 G/Flash project

Offline Frenchy

  • A's Best Friend
  • ***
  • Join Date: Oct 2009
  • Posts: 66
  • Karma: 0
  • 1957 A7
Re: no power
« Reply #11 on: 26.08. 2010 03:28 »
Thanks, Cus.  I'll do that Friday.  In the meantime here are some photos.  I put some notes on a few of them. 

http://www.flickr.com/photos/36327282@N07/
1957 A7 bobber, swing arm
Columbus, Ohio, US

Offline brackenfel

  • Valued Contributor
  • ****
  • Join Date: Jan 2010
  • Posts: 271
  • Karma: 2
  • Adrian - Bristol UK
Re: no power
« Reply #12 on: 26.08. 2010 07:26 »
Hi Frenchy,
As Cus says, get the cover off & have a look..
The hardest part on mine was getting the footrest off (shaft slightly bent and put in the wrong side with the head on the primary end!) - this makes it easier to remove the primary cover.

There are a couple of types, obvious when you get in there, 4 or 6 spring.
The springs have round slotted adjusters - if you can see lots of thread hanging out (which makes adjustment difficult - don't ask how I know!!) the plates are probably worn. They're freely available & not expensive..

Good luck,

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

Offline Pete Gray

  • A's Best Friend
  • ***
  • Join Date: Jun 2010
  • Posts: 148
  • Karma: 3
    • Scuppered Folk Band
Re: no power
« Reply #13 on: 26.08. 2010 09:50 »
Some very nice engineering there particularly the toolbox, well done.

Not being that well up on carburation but isn't the extra distance between the head and carb with the manifold adaptor a possible cause of the power problem ?

Pete

1961 Swinging arm A7
2000 BMW R1100R

Offline lawnmowerman

  • Resident Legend
  • *****
  • Join Date: Dec 2009
  • Posts: 614
  • Karma: 8
  • 1959 Super Rocket. Kent, England
Re: no power
« Reply #14 on: 26.08. 2010 10:14 »
Nice looking bike Frenchy - I am sure it will be worth the final fettling to get it right. The only thing I would point out is the carb manifold extension. There has been many posts about carburation problems and heat resistant spacers and bias spacers. The induction tract seems to be quite critical both in length and shape although I am no expert in this area and many others on the forum are and will no doubt have views. IMHO, it looks like the manifold extension is longer than it need be and you may get away with a heat reducing spacer (or two) with extended studs which will shorten the inlet tract. Also I think I read somewhere on the forum that the iron heads run quite hot so benefit from the spacer. It looks like the extension piece is solid steel so would transmit head heat to the carb - although the length may dissipate the heat.
Hope you get her running properly soon.

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)