Kevin Taylor wrote:
> Folks,
>
> Just an update on my rough running Subaru, please feel free to throw
> ideas at me if you have any.
>
> I spent the day messing around and didn't really get too far, let me
> tell you the symptoms and feel free to throw in any ideas, although I
> realise most of you have Rotax.
>
> Its intermittent rough running at low rpm tick over-3000 rpm,
> resulting in bad running?/vibration?/misfiring? (Engine cuts if I
> pull throttle back to idle)
>
> I drained and cleaned out the tank as the carb had what appears to be
> water and crap in!
>
> The voltmeter is odd and is reading 14-15 volts!? (If I take out the
> fuse for the alt charge it drops down to 12.5 ish where it should be)
>
> Leaning and carb heat appears to assist in easing the problem but
> doesn't cure it.
>
> Have checked the Diaphragm in the carb and it appears to be operating
> OK.
>
>
> Not sure where to start really.
>
> 1. Could junk in the carb but I have flushed it through now a good few
> times?
> 2. Could be ignition problem?
> 3. Could be a mixture problem
> 4. On the way home had an awful thought that the head gasket might
> have gone, water blowing back in to carb? I need to check the water
> level and oil I guess to confirm this is not the case.
>
> For info last set of plugs were blacker than normal, Oil change
> appeared to be OK, fitted new plugs and just had a though tonight I
> should check the gaps to make sure they were set right, although this
> problem was apparent on the last set of plugs.
>
>
> Maybe I have 2 problems? I've just had the panel out and something
> could be wrong there? giving the discrepancy in voltage.
>
> As I'm sure you have gathered from my description I'm not an engine
> man and am trying to ascertain the potential problem before deciding
> on my next steps to call in some reinforcements.
>
> Regards
>
> Kev T
Hi Kevin,
When charging, I would expect to see between 13 and 15V, the charge circuit
needs a slightly higher voltage to stop the battery 'blocking' the charge.
There are a couple of other things you should check:-
o Timing
o Advance/retard unit (if mechanical one used)
Does it run rough on both fuel pumps? Can you borrow a carb. from anyone?
(Sorry, my Subaru is fuel injected, but you can borrow my fuel system if you
want and if it fit's your engine).
Cheers,
Mark.
|