Author Topic: Inlet valve contamination.  (Read 481 times)

Offline alanp

  • Plymouth, Devon
  • Valued Contributor
  • ****
  • Join Date: Jul 2009
  • Posts: 473
  • Karma: 7
Inlet valve contamination.
« on: 13.06. 2014 17:46 »
I had my valves out the other day and was amazed by the hard lumpy contamination on the inlet port side of the inlet valves. I've never seen anything like it. I had to run the valves in my bench drill and use emery cloth to shift it. My guess is I'm looking at contamination from the ethanol in the petrol. It wasn't carbon build up from leaky valve seats or oil from down the guides, I would recognise that if I saw it. Anyone else seen this type of contamination?
Member of the 'Last of the Summer Wine Club - Jennycliff'.

Online Topdad

  • bob hebdon
  • Wise & Enlightened
  • *
  • Join Date: May 2011
  • Posts: 2280
  • Karma: 32
  • l
Re: Inlet valve contamination.
« Reply #1 on: 13.06. 2014 19:02 »
Alan think you're spot on probably one of the new things we can expect ,be even worse if they increase the. % of the muck !was it inlet or ex ? BobH
" rules are made for the guidance of wise men and the blind obediance of fools"
United Kingdom

Online morris

  • Wise & Enlightened
  • *
  • Join Date: Aug 2012
  • Posts: 1669
  • Karma: 26
  • Antwerp, Belgium
Re: Inlet valve contamination.
« Reply #2 on: 13.06. 2014 20:19 »
Hi Alan,
do you own the bike already a long time? Otherwise it may be the PO who used some dubious petrol. I had a mate once who was always short on money, and would throw in anything that looked and smelled vaguely like petrol...
Don't dare guess what his internals looked like. Of his bike I mean...
'58 BSA A 10 SA
'52 BSA A 10 Plunger
The world looks better from a motorbike