<VV> Ignition Timing?? Pertronix??

[P.H. Raker]

Hello, Bryan,
     See below:


--- On Wed, 8/6/08, Bryan Blackwell <bryan at skiblack.com> wrote:
> 
> I think now is the time to get a timing light - perhaps carry it with  
> you and see what goes on when the GB runs funny. 

To do that, I'd need a passenger who knows how to use a timing light who could read it while going down the road.  (It would have to be someone who doesn't mind straddling the open engine compartment while I'm driving.)  It only knocks when under load.  If I back way off the throttle or let it idle in neutral (or clutched), it's OK.  If I get back into the throttle again (still in the same gear - not lugging, but under 3000 rpm) it starts knocking again.

>
> Does the engine seem hot when this happens? 

It has no cylinder head temp gauge - only oil temp.  This is never above 220 degF.  The problem can occur at any time from initial drive-away through fully warmed up to normal operating temp.  The engine seems very cold-natured at start-up.  It generally lacks torque until it's well warmed.  I believe the accelerator pumps aren't working well.  I'd think THAT should only cause a transient difficulty (a brief lean stumble), which is far different from what usually occurs.

>
> One other question - are you sure it knocks first, or does the power 
> drop off and then it knocks when you try to maintain speed? 

It seems simultaneous.

>
> Are both damper doors open (if present)? 

Yes.

>
> If you shut it down and let it cool off, does it run ok then?

See my response to the "hot" question (above).


Phil (still puzzled) Raker




> On Aug 5, 2008, at 4:27 PM, P.H. Raker wrote:
> 
> > Hello, all you ignition experts,
> >      I'm finding a situation with my 'Brier
> 110/4 that puzzles me.   
> > Much of the time it runs wonderfully.  BUT,
> occasionally it will  
> > start pinging and knocking like someone has advanced
> the timing by  
> > about 15 degrees.  Of course, when that happens, it
> also gets very  
> > gutless - will hardly hold a steady speed.  If I can
> downshift or  
> > coax it up to 3000 rpm or more and hold it there for
> about 10-15  
> > seconds the problem usually seems to clear and it gets
> smooth and  
> > quiet again.
> >      It has a Pertronix 1 installed.  Is there
> something going  
> > crazy in the Pertronix unit?  Is it something else?  I
> can't think  
> > what else it could be.