[Healeys] A bit of tuning advice

Bob Spidell bspidell at comcast.net
Tue Jun 29 17:29:33 MDT 2010


re: 
" Sometimes if you get a strong pre-fire, it will cause the plug to 
dislodge slightly and create a vacuum leak" 

Or blow the thing out completely. 

Also, check for blockage in exhaust system. 


bs 

-------------------------------- 
Bob Spidell - San Jose, CA 


Paul - 

If your BN4 has the 12 port head, check the casting plug on the back 
of the intake manifold (the part facing the bulkhead). 

Sometimes if you get a strong pre-fire, it will cause the plug to 
dislodge slightly and create a vacuum leak. It can be very hard to 
see, you have to feel it with your hand - the plug is convex in shape 
with no lip. Feel around the circumference and if one side is poking 
out, that is your problem. 

Alan 

On 6/29/10, Paul Leeks <Paull at glasgows.co.uk> wrote: 
> After having problems with the poor running of my BN4, I put an electronic 
> ignition in the distributer (which was also overhauled) and rebuilt the 
> carbs 
> using a carb kit. However, I still can't seem to get any power. 
> 
> 
> 
> I am pretty certain that the timing is right (having checked it with a 
> timing 
> gun), all the electric connections (plugs, cables, etc.) seem to be sound 
> and 
> I cannot identify any specific problems with the carbs (ie leaks around the 
> inlet manifold, etc.). 
> 
> 
> 
> So I think the trouble is with the setting of the carbs, but I have been up 
> and down the adjustment nuts (rich to lean and back again) without any 
> success. 
> 
> 
> 
> The symptoms are ... a smooth idle, smooth but very sluggish pick-up on 
> acceleration accompanied by a loud machine-gun type rat-ta-tat-tat! 
> 
> 
> 
> Any ideas? 
> 
> 
> 
> Thanks 
> 
> 
> 
> Paul Leeks 
> 
> Lancashire 
> 
> 100/6 BN4 
> 
> 
> 
> Glasgows 
> Customs House, Customs Way, Preston, Lancashire, PR2 2UW 
> 
> Tel: 01772 767505 Fax: 01772 767566 
> Email: paull at glasgows.co.uk <mailto:paull at paull@glasgows.co.uk> 


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