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Thought I had seen it all, Folks.
An M88 for a WLC just came in from a Dealership, because it couldn't be tuned. No doubt.
The horrible reversed-throttle stop bodge (first attachment) probably had the body tossed in a bin for years before it was completely outfitted with Tedd hardware and bowl. There is no need to go into the endless problems with poor replacement hardware, or even that it had an OHV HS needle, main nozzle, and venturi, but I was amazed to see a very nice machine job on the manifold flange and aircleaner deck. Perhaps there was hope? Not.
The body had been partially over-bored (second attachment) for a Tedd nominal .030" oversize throttledisc (.0275" actually).
Since most bodies only need between .005" and .015" overbore, this means several 'lifetimes' of possible rebuilds had been hogged away.
The idle bleed slot was totally blocked with burr from the bore job (third attachment).
(We still do not know the effect of thinning the wall of these delicate metering orifices, but this one may give a clue.)
Now, brazing on a throttlestop and repairing the gouges risk distorting the bore, and the stepped bore prevents over-stroking with a hone.
Topping it all off was wonderfull O-ring job on a Colony venturi that could have been swaged. Apparently the rebuilder was a great machinist, but totally ignorant of the need for an air correction slot on an M88.
Never have I seen anyone go to such great lengths to get something so wrong.
....Cotten
An M88 for a WLC just came in from a Dealership, because it couldn't be tuned. No doubt.
The horrible reversed-throttle stop bodge (first attachment) probably had the body tossed in a bin for years before it was completely outfitted with Tedd hardware and bowl. There is no need to go into the endless problems with poor replacement hardware, or even that it had an OHV HS needle, main nozzle, and venturi, but I was amazed to see a very nice machine job on the manifold flange and aircleaner deck. Perhaps there was hope? Not.
The body had been partially over-bored (second attachment) for a Tedd nominal .030" oversize throttledisc (.0275" actually).
Since most bodies only need between .005" and .015" overbore, this means several 'lifetimes' of possible rebuilds had been hogged away.
The idle bleed slot was totally blocked with burr from the bore job (third attachment).
(We still do not know the effect of thinning the wall of these delicate metering orifices, but this one may give a clue.)
Now, brazing on a throttlestop and repairing the gouges risk distorting the bore, and the stepped bore prevents over-stroking with a hone.
Topping it all off was wonderfull O-ring job on a Colony venturi that could have been swaged. Apparently the rebuilder was a great machinist, but totally ignorant of the need for an air correction slot on an M88.
Never have I seen anyone go to such great lengths to get something so wrong.
....Cotten
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