Mon, 16 Feb 1998 09:54:24 +0100
- Message No. 2170
From: Sture Qvarfordt
Subject: Flat slide operation
Hej,
I have a RD07 and I have modified the air inlet, new exhaust, new main
jets, lifted the needle by 0,5 mm, and enlarged the little hole in the
slide to the diameter of the larger hole. I'm supposed to get a faster
response from the slide by increasing the air inlet at the bottom of the
slide. To much air inlet (to quick response) will choke the engine at
acceleration.
I have been wondering about the operation of the vacuum guided slide in
the carburetor. The slide, I guess, will be i balance between the two
forces working in opposite directions, the air pressure and the force of
the spring.
Will the change of the air inlet at the bottom of the slide affect the
balance, i.e. the position of the slide at a certain trottle position
(the circular one)? I have a problem with to lean mixture at the 4-5000
revs range. I should have increased the fuel flow be lifting the needle
but can it be opposed by a changed level of the slide? Is 0,5 mm too
little? The engine aspiration is now so easy that I have a correct
mixture at full rev with main jets of 140.
/Sture Q.

dipper@normans.isd.uni-stuttgart.de