Misfire

[900Rebuilder]

Originally Posted by motomartin11

My mate has just phoned me to say he is unable to stop the debris from the tank blocking the fuel flow to the carbs so I'm going to have the old tank repaired as I am advised putting in a liner will be too risky .

I assume that the debris you mention is rust? I've been having reasonable success with my Jeep tank and electrolysis.

Fill with water and some soda crystals then wire up to a battery charger (negative to tank) and pop in a piece of steel which will act as the sacrificial positive (make sure it doesnt touch the tank) and away you go. There are plenty of YouTube videos on the subject for the exact details of how to do it

[motomartin11]

Originally Posted by 900Rebuilder

I assume that the debris you mention is rust? I've been having reasonable success with my Jeep tank and electrolysis.

Fill with water and some soda crystals then wire up to a battery charger (negative to tank) and pop in a piece of steel which will act as the sacrificial positive (make sure it doesnt touch the tank) and away you go. There are plenty of YouTube videos on the subject for the exact details of how to do it

Thanks...I did consider this and it would certainly be worth a try but I'm so demoralised with this tank that at the moments I'm going to stick with the plan to repair the original tank which is internally (apart from the slight weep near the hinge) in much better condition than the second tank. Interestingly the second tank has already been repaired in this area.
As to the debris this is tiny paint / rust flakes and a fine sand like substance. If you put your finger on what has come out of the tank after flushing -after the water has evaporated away-you can feel the sand like substance on your fingers.
There has been a fair amount of speculation as to what has happened historically from attempts at sand blasting not being cleaned out thoroughly to corrosion both as a result of time and possibly from what occurred after the welding had been completed as it seems the tank may have been stored for a time after the welding has been carried out. It also seems likely poor preparation of the internal tank surfaces is an issue. There is also some evidence of other bodged repairs using resin type substances-hence the reluctance to continue using the second tank. There is a load of debris which can be seen in the new fuel filter and the small diameter fuel outlet in the tank doesn't help as this is becoming blocked and cutting off the fuel supply.

[900Rebuilder]

I dont understand where its all coming from then if you have cleaned it out once and you are starting each time from a clean tank. What ever is in there must not be fully coming out each time as I cant see a full petrol tank rusting quickly enough to cause your issues each time.