Fuel problems.

[Stormin 4,458]

  The C-121, Black Horse, started to refuse to run right after standing all night in the cold at the HVC rally. Would only run on half choke. Managed to get it to where it was on display with it's stable mates.

  When the rally ended and I eventually found the time to load up, it refused to start at all. With some help it was pushed up onto the trailer. Back home and rolled off and put away.

  The following morning I decided to investigate, as I wasn't due back at the rally site till after lunch, (1 day rally. 5 days work.) to collect the cattle trailer loaded  with rally equipment., to take back to the farm.

  Good spark from the plug but plug dry. Disconnected pump from carb and a good flow through the pump. Removing float bowl from carb revealed bits of black dirt in there. So off with carb and cleaned out the jets. In line filter look clean so I drained the fuel tank. Some dirt was evident in the fuel, so I removed the tap. I then poured fuel into the tank to flush it out.

  After putting everything back together, the engine fired up straight away. I then tuned the carb and now he Black Horse runs as normal.

 I suspect the bouncing of the trailer disturb some bits of dirt. Hopefully all will be back to normal, but if it happens again I will take the tank out for a thorough clean and also replace the fuel lines in case the are starting to deteriorate inside

[Westie1 29]

How would you recommend cleaning these plastic tanks? Nuts and stardrops be ok?

[Wristpin 399]

Don’t think that you need anything too harsh or abrasive as in a plastic tank there is not usually any bound on dirt like rust to steel. I would remove the tank, seal off the outlet and add an inch or so of fuel and give it a good swirl round then pour it back into a can via a gauze filter funnel with a bit of blue roll in it as an additional filter paper. While pouring try to keep the fuel swirling to help any debris in suspension. Then have a look at the blue filter and see what may have been captured.

As an aside and not wishing to insult anyone, I used to regularly see people sealing off fuel pipes with a handy bolt. The problem is that the threads act as a rasp and loose of bits of pipe material which tend to fetch up where they aren’t welcome. Other than using the proper clamps, when scrapping an engine I used to save the mushroom cam followers. They are hard, polished and have slightly tapered ends and are unlikely to cause the above issues. Two or three different diameter ones are useful emergency bungs.

[Westie1 29]

Thanks ive 2 so ill pick the best and give it a clean as you suggest