10/4/2012 – 15/4/2012
After browsing the vehicle and deciding that it deserves to be restored for active pickup truck duty (and not a wussy trailer baby), I purposed that the first logical thing to do would be to check for a heartbeat. I knew that with the fuel pump already out it wouldn’t be drinking on its own, and since the carb had a stuck butterfly it wouldn’t be throttling on its own either. First a check of the main belt driven parts to check for seized parts; with a green-light here I slotted a good battery in and hooked up the decrepit battery cables to see if the vintage Flathead would pulse. I had music to the tune of about 3 seconds of rollover before the old battery cables gave up to current, but it told me that there was life in the starter, and that the motor wasn’t seized (it has been sitting with new oil in the pan so that is a huge plus).
With this in mind I didn’t fry anything else by continually rolling it. I will simply pick up some universal cables and re-wire the battery so it is less prone to shorting on the body. About 4 minutes of work had the tall-stack Carter Carb off of the side ported cast manifold and in my hand (leaking thick stale gas everywhere) bound for some rebuild work. I will shop around for a rebuild kit but for now the guts looked ok.
Taking the fuel pump apart revealed that the workings were a bit frozen from lack of use, but freed up once I got it all apart. The diaphragm’s inside looked ok too, but re-hosing everything will be a bit of a trick. Taking the carb apart revealed that several years of sitting rendered this carburetor a sludgy mess. It was in desperate need of a cleaning beyond what an old toothbrush can offer, leading to my recollection of a classmate who boiled his bike’s carb in lemon juice to clean it all up.
El Cheapo no-name Lemon juice in hand, I poured “the equivalent of 42 lemons” into an old drawn-steel soup pot; nice and deep for the legendary foam lemon juice creates. I brought it to a rolling boil and slipped the carb parts into the bath, bringing the juice down to a simmer to hold the boil without going overboard. The recipe (if you want to try this at home) goes like this:
- 1 pot; large enough for your parts and the juice, deep enough so it won’t boil over
- Enough lemon juice (even cheaper is white vinegar, which I found out about after) to just cover the part. I used 2x946ml bottles. You can add water to bring this level up
- Bring juice to a boil and set parts in. let simmer/boil for 20 minutes, moving the parts around periodically and turning to allow total penetration.
- Remove parts and place into tub of hot water with dish soap. Scrub off the lemon juice varnish with a toothbrush.
The results this method produced were unbelievable, working on both the white metal (or aluminum, I’m not sure) of the carb, and even better on the cast iron of the main butterfly section. I have no doubt that with this carb back together and properly adjusted; the engine is going to purr. Next is to try boiling the pump in vinegar to see if that manages to do the same thing. With standard vinegar having a 5% acetic acid content I should be fine. Next steps are to put these pieces back together and mount them back on the truck. I am tempted to give them a shot of paint to give them a cool shot of colour and protect them from future grime buildup.