Author Topic: RHS Exhaust blue A7  (Read 633 times)

Offline Pawack

  • Moving Up
  • **
  • Join Date: Oct 2014
  • Posts: 8
  • Karma: 0
RHS Exhaust blue A7
« on: 26.03. 2015 23:13 »
Hi Guys. My 51 A7 is running a dream following rebuild. No backfiring, good power, starts first kick. One thing annoying me is one exhaust turned blue within the first 20 km of riding and the other is bright shiney  chrome and not a hint of blue. The blue is only for the first 4 inches. Have checked the valves.  Do I ignore and enjoy the riding or go tampering?

Cheers, Paddy
 
1966 Dnepr 750 Sidecar
1951 BSA A7
Ireland

Offline Andreas Larsen

  • A's Best Friend
  • ***
  • Join Date: Feb 2014
  • Posts: 62
  • Karma: 1
Re: RHS Exhaust blue A7
« Reply #1 on: 27.03. 2015 10:35 »
Hey Paddy,

I had a similar problem with my A10 and I was quick to judge it as what I think is called induction bias, but it turned out I had a minor air leak at the carb flange that solved itself when I got a new o-ring for the carb and a new gasket - the old one had turned almost rock solid.

Andreas

Edit: I was a bit quick to drop the induction bias in here, but as I recall the A7 is not prone to that particular problem, but I'm sure some of the guys on here may be able to confirm if my memory serves me right.
'58 A10 swingarm

Online bsa-bill

  • Wise & Enlightened
  • *
  • Join Date: Mar 2006
  • Posts: 5557
  • Karma: 65
Re: RHS Exhaust blue A7
« Reply #2 on: 27.03. 2015 11:51 »
Yes I had that problem with the RGF, put mine down to a sticking EX valve on that side, but would not rule out other causes, bit annoying as you see many bikes with blue pipes but on both side and they seem to go well enough, I prefer the gold colour tho.
Took a good  bit of elbow grease and chrome polish to get rid of it and it hasn't come back but I do wonder what so much polisking does to the chrome?
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

Online Butch (cb)

  • Wise & Enlightened
  • *
  • Join Date: Aug 2010
  • Posts: 1574
  • Karma: 15
Re: RHS Exhaust blue A7
« Reply #3 on: 27.03. 2015 13:40 »
Heat wrapped mine.
Warning - observations made by this member have a 93% unreliability rating.

Of Bikes; various, including ...
'58 Iron Head Flash Bitza


Online bsa-bill

  • Wise & Enlightened
  • *
  • Join Date: Mar 2006
  • Posts: 5557
  • Karma: 65
Re: RHS Exhaust blue A7
« Reply #4 on: 27.03. 2015 15:12 »
Heat wrapped mine.

do you mean with that asbestos tape stuff, does that not make the engine run hotter
I'm curious as I never understood why that was done, nothing against it at all just not my look

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

Online Butch (cb)

  • Wise & Enlightened
  • *
  • Join Date: Aug 2010
  • Posts: 1574
  • Karma: 15
Re: RHS Exhaust blue A7
« Reply #5 on: 27.03. 2015 16:24 »
All iron motor. Smells hot when I’ve been out. Hasn’t melted or seized yet. Covers up the original rusty downpipes on an otherwise restored bike. Armours screwed me over on the replacements that didn’t fit and they refused to accept back = cheap cosmetic fix. I’ve kind of got used to it now, looks a little raffish I like to think. 
Warning - observations made by this member have a 93% unreliability rating.

Of Bikes; various, including ...
'58 Iron Head Flash Bitza


Online chaterlea25

  • Wise & Enlightened
  • *
  • Join Date: Jun 2009
  • Posts: 3367
  • Karma: 48
Re: RHS Exhaust blue A7
« Reply #6 on: 27.03. 2015 18:25 »
Hi Paddy,
Along with the advice already given, check the ignition timing on both cylinders,
quite often the timing is not an even 180deg split ???
one cylinders timing retarded will cause pipe blueing
there can be a few reasons why this happens, and there are several topics on the subject on here already
Firstly check tha points gap on both cams and compare

Regards
John
1961 Super Rocket
1963 RGS (ongoing)

Offline Pawack

  • Moving Up
  • **
  • Join Date: Oct 2014
  • Posts: 8
  • Karma: 0
Re: RHS Exhaust blue A7
« Reply #7 on: 28.03. 2015 10:34 »
Right. Thanks all for the advice. Paddy
1966 Dnepr 750 Sidecar
1951 BSA A7
Ireland

Offline nimrod650

  • Valued Contributor
  • ****
  • Join Date: Feb 2015
  • Posts: 446
  • Karma: 4
Re: RHS Exhaust blue A7
« Reply #8 on: 02.05. 2015 19:21 »
an old dodge was to put copper wire around pipe a  few times near the ex clamp