7 replies to this topic

[tamlamotown123]

Hi I recently posted a problem regarding fuel starvation and received good suggestions on what to check. Carbs have been checked and functioning, new float valves too.

 

This week all rubber hoses have been fully  checked or renewed but still the problem existed.

 

Today I put a clamp on the inlet hose to the electric pump, then released the clamp and expected the fuel in the tank to drain out, but nothing came out.!!!

 

So I blew into the pump end of the hose, there was no resistance and air bubbles was observed in the fuel tank through the filler cap.

 

There s enough fuel in the tank as observed, fuel is clear, there appears to be an inbuilt tank filter at the bottom of the tank, is this right?

 

Any ideas why the tank did not drain and my next move?

 

Thanks

[Tornado99]

I think there is a metal sieve/screen in the tank outlet pipe. This can clog up. Has your tank been lined with any kind of protective coating. This is common to see in classic motorcycles but can/has been done in our minis at times. These can plug up the sieve if steps are not taken to prevent during coating process or if not cleared afterwards.

Also, when you tested fuel flow out the disconnected pipe, was fuel filler cap open? If not repeat with it open. Could be your tank vent is clogged, creating a vacuum effect when fuel tries to leave. Your tank may have a vent hose at top or may rely on the tiny hole in underside of cap sealing plate. Need to check they are clear.

[ThermalEvent]

I caused myself some starting issues when I cleaned my fuel tank with citric acid and then used POR fuel tank sealer.

Turns out it blocked the suction strainer in the tank. Had to remove the fuel tank sender and then remove the gauze filter on the pick up pipe with a prybar and calibrated impact tool. Added an inline filter and jobs a good'un 👍

[Spider]

There is a strainer on the outlet pipe in the tank. They are made from nylon. I make a point of breaking them off, I don't think they are too smart as they aren't serviceable. I just run one filter, after the pump, but of you're worried about crud from the tank, fit one before the pump - at least what ever is there will be serviceable.

If you have an electric diaphragm pump and a pre-pump filter though, be sure to check or replace the filter often. If that filter blocks up you will burn out the pump.

[Chris1275gt]

I had fuel problems traced to the nylon strainer that as you can see the mesh is really fine.

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Edited by Chris1275gt, 18 September 2021 - 10:18 PM.

[Tornado99]

I caused myself some starting issues when I cleaned my fuel tank with citric acid and then used POR fuel tank sealer.

Turns out it blocked the suction strainer in the tank. Had to remove the fuel tank sender and then remove the gauze filter on the pick up pipe with a prybar and calibrated impact tool. Added an inline filter and jobs a good'un

 

 

Viddy of how to clear such a blockage without doing your steps:

 

[tamlamotown123]

Hi, many thanks to Tornado99,ThermalEvent,Spider,Chris1275gt and Supermadmini for your advise on my fuel problem.

 

I took the tank out yesterday ,and yes thats the problem "blocked tank outlet.

 

What a relief! , best regards to all   

[bpirie1000]

Could say that fueled your thoughts.....