09-07-2016, 11:28 AM
i have a considerably better understanding of the tilly alky carb now.
i've redone several and track tested them and have gotten extremely good results.
i have one more race (cuddeback) to do and then i should have time for pix.
as winter sets in i'll be posting all the stuff i've sharpened up on during this season.
the scope of this thread expanded into setting up dual carbs.
as soon as i get time to load pix and add text.
i have always liked dual carbs but was told except for the hartman gears there wasn't a good simple linkage set up.
the gem set up works really well but the long cable makes removing a single carb a real pain.
i'd bought out a fellow with several cresent dual carb mechanical linkage set ups but never could get one to work correctly.
i've let it ruminate in my mind and finally the correct set up popped into my head.
i'll be posting the how to's on that as a separate thread along with the gem dual and the hartman gear dual.
the nice part about the cresent stuff is it's mostly stock tilly parts re purposed and repackaged.
so getting parts should be simple??
anyway first tech hint which i'll be repeating.
removing the weltch plug is vital in any good rebuild.
the issue is theres almost ZERO wiggle room for drill bit penetration.
if you go too far you just scrapped the carb.
E.C. Birt suggests using a milling machine or bridgeport or recutting your drill bit to a shollower angle.
all easay stuff for the gearhead/machinist but a little harder for a home style shade tree guy.
so i thought about it a little.
most people have a dremel tool or at least a small hand drill.
so here's what cha do.
get a small round head diamond burr home depot even sells them.
install in power tool and grind , at an angle, a hole through the weltch plug.
as you're grinding lift the burr every few seconds to check progress.
you'll see when you just break trough the steel plate.
STOP as soon as a hole appears.
as long as you don't try to go straight in it's impossible to drill through the carb floor if you pay attention.
pry the weltch plug out with a small hook tool.
at least this way you save a trip to the machinist and don't need to own a bridgeport.
After you check the three holes for sizing carefully install a new welsh plug.
a small punch is needed to tap the center of the arch in the welsh plug to trap it in the hole.
further sealing the welch plug with epoxy is advised.
A side note:
Steve Welte has advised super glue seems to work well on sealing the welsh plug when you replace it.
he also reports having had no problem drilling the plug out with a 1/8" bit, SLOWLY.
Get a hole in it and pop it out with an awl.
dave l.
i've redone several and track tested them and have gotten extremely good results.
i have one more race (cuddeback) to do and then i should have time for pix.
as winter sets in i'll be posting all the stuff i've sharpened up on during this season.
the scope of this thread expanded into setting up dual carbs.
as soon as i get time to load pix and add text.
i have always liked dual carbs but was told except for the hartman gears there wasn't a good simple linkage set up.
the gem set up works really well but the long cable makes removing a single carb a real pain.
i'd bought out a fellow with several cresent dual carb mechanical linkage set ups but never could get one to work correctly.
i've let it ruminate in my mind and finally the correct set up popped into my head.
i'll be posting the how to's on that as a separate thread along with the gem dual and the hartman gear dual.
the nice part about the cresent stuff is it's mostly stock tilly parts re purposed and repackaged.
so getting parts should be simple??
anyway first tech hint which i'll be repeating.
removing the weltch plug is vital in any good rebuild.
the issue is theres almost ZERO wiggle room for drill bit penetration.
if you go too far you just scrapped the carb.
E.C. Birt suggests using a milling machine or bridgeport or recutting your drill bit to a shollower angle.
all easay stuff for the gearhead/machinist but a little harder for a home style shade tree guy.
so i thought about it a little.
most people have a dremel tool or at least a small hand drill.
so here's what cha do.
get a small round head diamond burr home depot even sells them.
install in power tool and grind , at an angle, a hole through the weltch plug.
as you're grinding lift the burr every few seconds to check progress.
you'll see when you just break trough the steel plate.
STOP as soon as a hole appears.
as long as you don't try to go straight in it's impossible to drill through the carb floor if you pay attention.
pry the weltch plug out with a small hook tool.
at least this way you save a trip to the machinist and don't need to own a bridgeport.
After you check the three holes for sizing carefully install a new welsh plug.
a small punch is needed to tap the center of the arch in the welsh plug to trap it in the hole.
further sealing the welch plug with epoxy is advised.
A side note:
Steve Welte has advised super glue seems to work well on sealing the welsh plug when you replace it.
he also reports having had no problem drilling the plug out with a 1/8" bit, SLOWLY.
Get a hole in it and pop it out with an awl.
dave l.