Author Topic: Top end strip  (Read 1557 times)

Offline tlmark

  • A's Best Friend
  • ***
  • Join Date: Aug 2016
  • Posts: 196
  • Karma: 2
  • Maidstone, Kent
Top end strip
« on: 12.03. 2017 14:03 »
My plan had always been to try to fix some of the oil leaks and track down why the left cylinder would smoke, over the winter.
best laid plans and all that busy at work and a bad dose of the Flu which over 4 weeks later is still not gone.

Anyway so this weekend I started the top end strip and it looks like the exhaust valve is the culprit what do you guys think? 

Online edboy

  • Valued Contributor
  • ****
  • Join Date: Oct 2012
  • Posts: 436
  • Karma: 3
Re: Top end strip
« Reply #1 on: 12.03. 2017 18:52 »
it looks like oil is blowing across from the pushrod tunnel to me.

Online Klaus

  • Valued Contributor
  • ****
  • Join Date: Jun 2015
  • Posts: 376
  • Karma: 10
Re: Top end strip
« Reply #2 on: 12.03. 2017 20:56 »
Have a check at the valve guid, or a pistonring is brocken.
Your headgasket is one I would throw it to scap. It dont fit the bore realy good.
 I made my own gaskets of 0.8mm copper special for any singel barrel.


If you think, everything is under control, you are not fast enought.

Offline BSA_54A10

  • Wise & Enlightened
  • *
  • Join Date: May 2008
  • Posts: 2018
  • Karma: 32
    • BSA National
Re: Top end strip
« Reply #3 on: 13.03. 2017 10:03 »
Inlets suck and exhausts blow so no the oil is not coming in the exhaust it is blowing out the exhaust & burning on the red hot valve.
Bike Beesa
Trevor

Online Greybeard

  • Jack of all trades; master of none.
  • Wise & Enlightened
  • *
  • Join Date: Feb 2011
  • Posts: 6185
  • Karma: 35
Re: Top end strip
« Reply #4 on: 13.03. 2017 11:12 »
When I last looked inside my A10s head it looked rather like that. I put it down to too much use of lead additive/octane improver and too many short runs. I now do not use additive and I try to get the old girl hot, (also the motorcycle!)

Offline tlmark

  • A's Best Friend
  • ***
  • Join Date: Aug 2016
  • Posts: 196
  • Karma: 2
  • Maidstone, Kent
Re: Top end strip
« Reply #5 on: 14.03. 2017 11:19 »
Thank for the ideas Guys.

Some progress I've removed the suspect exhaust valve only to find the edge is damaged?
there is no evidence of it hitting anything on the head. I'll have to clean the piston crowns and check those but the damage is at an odd place?

Anyway so it's gonna need a new valve at least.
check the pix and see what you think?

Online muskrat

  • Global Moderator
  • Wise & Enlightened
  • **
  • Join Date: Jul 2009
  • Posts: 8269
  • Karma: 106
  • Lake Conjola NSW Oz
    • Shoalhaven Classic Motorcycle Club Inc
Re: Top end strip
« Reply #6 on: 14.03. 2017 11:44 »
G'day tl.
She's started to burn. The most common cause is the valve not seating properly. This can be caused by the tappet clearance being too tight or riding, lean fuel/air mix, retarded ignition. This all creates excess heat which wears the valve and seat till it leaks, then erodes the valve.
Might be time for a head job  *shh*
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
Muskys Plunger A7

Offline tlmark

  • A's Best Friend
  • ***
  • Join Date: Aug 2016
  • Posts: 196
  • Karma: 2
  • Maidstone, Kent
Re: Top end strip
« Reply #7 on: 14.03. 2017 12:51 »
Ha Ha yeah I'm thinking the same I have found some corresponding damage on the valve seat  *sad2*

Offline coater87

  • Wise & Enlightened
  • *
  • Join Date: Jul 2008
  • Posts: 1181
  • Karma: 6
Re: Top end strip
« Reply #8 on: 14.03. 2017 19:31 »
 I always look at this kind of thing as opportunity.

 Done right, the head will be better than new and last a long time.

 Done "good enough for today" just means doing it again tomorrow. *sad2*

Lee
Central Wisconsin in the U.S.

Offline tlmark

  • A's Best Friend
  • ***
  • Join Date: Aug 2016
  • Posts: 196
  • Karma: 2
  • Maidstone, Kent
Re: Top end strip
« Reply #9 on: 16.03. 2017 20:28 »
I have packed the head and shipped it of to SRM for look and Recommissioning.
I decided as newbe with classic bikes I should start with a clean slate

Offline tlmark

  • A's Best Friend
  • ***
  • Join Date: Aug 2016
  • Posts: 196
  • Karma: 2
  • Maidstone, Kent
Re: Top end strip
« Reply #10 on: 26.04. 2017 12:26 »
My head is back from SRM.  *wink2*

hopefully get to work on it this weekend

Offline ralph

  • Moving Up
  • **
  • Join Date: May 2016
  • Posts: 27
  • Karma: 0
Re: Top end strip
« Reply #11 on: 26.04. 2017 23:28 »
My head is back from SRM.  *wink2*

hopefully get to work on it this weekend

gosh that looks tasty work. I think I'd be tempted to go another step and treat the engine to new rings. But you know their history...........
Iron head A10, Panther 120, BMW RS100, Norton 500T special,

Offline coater87

  • Wise & Enlightened
  • *
  • Join Date: Jul 2008
  • Posts: 1181
  • Karma: 6
Re: Top end strip
« Reply #12 on: 27.04. 2017 00:52 »
My head is back from SRM.  *wink2*

hopefully get to work on it this weekend

gosh that looks tasty work. I think I'd be tempted to go another step and treat the engine to new rings. But you know their history...........

 I second that. I would at least pull the cylinders and check the condition of the rings if you have any doubts at all. At this point it only costs a little time and a base gaskets..
Central Wisconsin in the U.S.

Offline tlmark

  • A's Best Friend
  • ***
  • Join Date: Aug 2016
  • Posts: 196
  • Karma: 2
  • Maidstone, Kent
Re: Top end strip
« Reply #13 on: 28.04. 2017 11:43 »
I had the barrels off while I was waiting for the head to be finished and it all looks fine (fingers crossed)  ;)


Offline TT John

  • A's Best Friend
  • ***
  • Join Date: Jan 2012
  • Posts: 213
  • Karma: 2
Re: Top end strip
« Reply #14 on: 30.04. 2017 13:47 »
Don't forget to fit a new set of Solid copper rocker box gaskets when you re assemble the top end, still available from me at ?16 Plus p+p. Make it easy on yourself, I think I could write a song about that. *smile* *smile*

TTJohn