Cleaning Fuel Pump Filter

[Justin Hambleton]

Anyone have any tips on cleaning the fuel pump filter? I had a race this weekend and my dump can introduced a bit of dirt into the tank. I drained and filtered the remaining gas and removed and disassembled the fuel pump. What is the best way to clean the fuel pump filter?

Edited December 6, 2011 by Justin Hambleton

[FORMA MOTO]

According to MXA, use sink dishwashing liquid soap.

[kx450f63]

No good way. Anything you put on that filter to clean it will get in the pump. If you are worried about it, I would say remove the rubber cover and fill a glass container with clean fuel and shake the pump assembly around in the clean fuel. You will then be able to see if you are actually cleaning anything. I did spray mine one with carb. cleaner once, it didn't seem to hurt anything.

Just remember, don't remove the filter from the pump, it will not go back on. It is a one time use.

[Justin Hambleton]

Thanks for the feedback guys. I'm not going to worry about it. There wasn't nearly as much dirt as I was expecting once I drained the tank and removed the fuel pump. None at all really.

Regular fill caps are easy to filter the fuel before it enters the tank. Dry breaks are a different beast, especially when fueling mid race. Gotta keep a lot of dust caps on hand.

[kx450f63]

Obsessive compulsive disorder comes with the territory when you start going fast on a dirt bike and you know the consequence. Think about it like this... when was the last time you cleaned the filter for the fuel pump in your truck or car? Never, rite, the filter that is on your mx bike is much better than what is in your truck. So you did the rite thing. Pull it apart, look in the tank, remove any large debris and inspect the filter for any obvious damage then re-install and go race.

I have seen some fuels deteriorate the filter material in the Honda's to the point it would starve the pump. You can tell this by trying to blow through the filter, if little air passes then little fuel will pass.

[FORMA MOTO]

Obsessive compulsive disorder comes with the territory when you start going fast on a dirt bike and you know the consequence. Think about it like this... when was the last time you cleaned the filter for the fuel pump in your truck or car? Never, rite, the filter that is on your mx bike is much better than what is in your truck. So you did the rite thing. Pull it apart, look in the tank, remove any large debris and inspect the filter for any obvious damage then re-install and go race.

I have seen some fuels deteriorate the filter material in the Honda's to the point it would starve the pump. You can tell this by trying to blow through the filter, if little air passes then little fuel will pass.

You make a good point about the filter, but the holes in the injector in your truck are 15 times larger.....much less likely to clog.

[kx450f63]

the holes in the injector in your truck are 15 times larger.....much less likely to clog.

15 times is much larger. I don't think that is accurate. Just because the truck is big... doesn't mean the injectors are. (I am referring to gasoline powered passenger trucks)

Do you have any proof of this? (hole size in relation to clogging)

I try not to clutter my brain with facts I don't need (not enough room as it is) so I don't remember the size of the holes in either injector. When I think about the comparison of one cylinder in our modern mx 450 cc bikes that produces about 50 HP to one cylinder of a typical truck, say 5300 cc that produces about 40 HP, which injector due you think should be taxed more, have larger holes, or flow more pounds per hour?

The filters are sized in such a manner to not allow anything large enough through that could potentially harm the pump, injector, or any part of the fuel system down stream of the filter.

In the case of a truck there is a secondary filter after the pump and before the injector just because they know they didn't filter the fuel well enough the first time. (before the pump) There are other reasons also, but this one covers my case.

[FORMA MOTO]

15 times is much larger. I don't think that is accurate. Just because the truck is big... doesn't mean the injectors are. (I am referring to gasoline powered passenger trucks)

Do you have any proof of this? (hole size in relation to clogging)

I try not to clutter my brain with facts I don't need (not enough room as it is) so I don't remember the size of the holes in either injector. When I think about the comparison of one cylinder in our modern mx 450 cc bikes that produces about 50 HP to one cylinder of a typical truck, say 5300 cc that produces about 40 HP, which injector due you think should be taxed more, have larger holes, or flow more pounds per hour?

The filters are sized in such a manner to not allow anything large enough through that could potentially harm the pump, injector, or any part of the fuel system down stream of the filter.

In the case of a truck there is a secondary filter after the pump and before the injector just because they know they didn't filter the fuel well enough the first time. (before the pump) There are other reasons also, but this one covers my case.

There was a post in the Jetting section that went into details about how MC off-road injectors use more smaller holes than any other injector currently being used, and why that was the primary issue for the delay in off-road competition motorcycle FI systems...filtering, varnishing, and leaking issues due to the new kind of injectors, and smaller holes.

[kx450f63]

I'm with ya Krannie. I will search for that thread to check it out. Referencing your last post, I don't see why people would think they needed to reinvent the wheel here. DFI has been around for quite a long time including injector technology. I haven't looked at the injectors they put in these bikes yet, but I would be willing to bet the manufacture has been using them in a different application before MX.

Anyway, I don't think clogging of the injector is an issue if the filter is not compromised.

[demon2003]

There was a post in the Jetting section that went into details about how MC off-road injectors use more smaller holes than any other injector currently being used, and why that was the primary issue for the delay in off-road competition motorcycle FI systems...filtering, varnishing, and leaking issues due to the new kind of injectors, and smaller holes.

I find this odd since the kx450 injector is used in the ZX10.