Above: stripped and complete carbs
Before you dive in, thinking you are going to eliminate your carburettor as the trouble with your VIRE, BE WARNED - it's not all here, and there are still things I cant see after doing dozens of repairs - that is why i
supply only tested on the boat - new and rebuilt exchange carburettors.
You might be lucky, certainly changing the diapragm should be done every 5 years, and internal grit and corrosion might be the cause of flooding, even poke clear the jets if you can find them, but even if you do
all this and it looks fine, there is in my experience 50% chance it will still play up.
So if you want to ELIMINATE the carb in one go, contact me for a replacement. As of July 2006 I have now ressurected drawings and new parts to be able with the cooperation of the manufacturers, a brand
new Vire 6/7 tillotson with the correct pies and modifications needed. This carb will be offered fully tested under full load and ready to fit. I also offer exchange teseted/tuned carbs - see my parts page to contact me / order.
Anyway if you are still keen to have a go.......
the tillotson HL carburettor manual is here
Before stripping, you can check the fuel pump diagragm hasnt ruptured
suck on the pipe going from the crankcase - there should be a resistance, if you can suck air thru - the diapragm must be broken/leaking.
another check is to make sure jets and galleries are clear
before removing low (idle-screw) and high (power-Tbar) speed jets from the side, it is worth noting how many turns out they have been adjusted to (count the turns to the nearest eight'h of a turn until
the jet GENTLY comes to a stop. noting the turns for each
place a bowl/tray to catch the petrol, remove the two jets.
remove the HT cap to prevent firing, and run the engine - this will eject/clear debris from the galleries, and give you an indication of the fuel supply, and contamination if any. you can also inset a
piece of 1/4" (like used in windscreen washer) tube into the jet and blow out any grit?
it might be possible to make a wire tool to clean out the bleed holes, but id advise removing/stripping instead
replace the jets, resetting them to the original turns-out, or 1+1/4 turns out if you forgot.
if the crank case pipe is not connected it wont pump fuel
if the carb is flooding/leaking fuel - suspect the float-diapragm is compromised/leaking
I have been rebuilding these carbs for years now, and i find that i can often offer a rebuilt, cleaned and tested/tuned carb ready to go for owners.
Unfortunately the bodies are alluminium which powders-up unless covered in WD40 or run regularly. If you are winterising, and not running for over a month, I suggest you spray it with WD40 and wrap an oily
rag/bag around it to reduce the salty air flowing over it.