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Re: Probably a really stupid question, but...

To: spitfires@autox.team.net
Subject: Re: Probably a really stupid question, but...
From: Michael Hargreave Mawson <OC@46thFoot.com>
Date: Tue, 27 Jan 2004 16:55:28 +0000
On Mon, 26 Jan 2004, at around 19:00:04 local time, Michael Hargreave 
Mawson <OC@46thFoot.com> wrote:
>...is my Spit running on only two cylinders?

>I shall be checking the tuning tomorrow, but if you have any other 
>ideas or suggestions, I'd be delighted to hear them.

Dear All,

Many thanks to those who replied with comments and suggestions to my 
message of yesterday.   I did play with the fuel supply and tuning 
today, and found that the rear carb was set very lean.   As a result of 
my fiddling, I now have the following symptoms:

- Noticeably increased power

- Much quieter engine

- Much deeper and nicer exhaust note

- Much smoother delivery of power when I press the accelerator

Unfortunately, I also have the following symptoms:

- The engine revs "hunt" whilst at idle; typically by about 200 revs, 
but occasionally by well over 1000 revs, between c. 700 and c. 1900 
revs.

- As a result of the "hunting", the slowest idle I can reliably set is 
approx. 1600 RPM, as anything slower than that stalls the engine at the 
bottom of the cycle.

There is obviously something wrong here, but I cannot fathom it. Please, 
someone, put me out of my misery!   What could cause this?   If all else 
fails, I shall just have to bite the bullet and pay someone to tune the 
thing for me - but I hate to admit defeat...

With regard to the behaviour of the engine when HT leads are 
disconnected, they do now at least all do the same thing. Disconnecting 
any one HT lead now has practically no effect on the engine note or 
revs.   Pretty forgiving, these engines, aren't they?

ATB
-- 
Mike
Ellie  - 1963 White Herald 1200 Convertible GA125624 CV
Connie - 1968 Conifer Herald 1200 Saloon GA237511 DL
Carly  - 1977 Inca Yellow Spitfire 1500 FH105671





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