Pulse Pump Fuel Filter confusion

[CLH]

Hi, I'm trying to figure out the correct inline fuel filter to use with my Walbro pulse pump. It is powering a 7hp Tecumseh engine.

I've currently been using a sintered bronze filter like this. Problem is that I don't know the micron rating or if it's correct for using with my fuel pump: Sintered bronze fuel filter

I have had it hooked up to the pulse pump and been riding around, and seems to have been working fine, but I want to be certain I'm using the correct filter for my application. I haven't heard anything about the sintered brass style of filters being used with a pulse fuel pump. I've seen disc type w/ screen element, a sort of inline oblong type screen element, and even a suggestion to use a paper element type filter. My real confusion is what micron rating to use for optimal performance.

I found some OEM Briggs 75 micron disc style screen element filter that this and a couple other sellers claims can be used with a fuel pump. The seller doesn't specify what kind of pump, but I assume it's for your typical small engine/riding mower which mostly all use pulse pumps. See it here: OEM Briggs 75 micron disc style fuel filter

What confuses me is there is a seller from China who lists the same part number for a 75 micron filter, but claims it is for engines without a fuel pump Chinese 75 micron fuel filter I have a sneak of suspicion that is erroneous though. Maybe the seller saw WITH and typed WITHOUT?? They also claim it's for 5/16 fuel line...which is weird because no small engines really use 5/16 fuel line that I know of..its all 1/4 inch. So it might not even fit.

This pulse pump on eBay comes with a inline screen type filter Pulse pump with screen Is this type what I should be using? Seller doesn't say what micron the filter is.

I found a pretty good thread on another forum, and a couple people said the disc screen briggs type will work, (the consensus from all my sources sounds like the Briggs 75 micron disc type for fuel pump will work) and that a paper element type filter will work for a fuel pump application too (but not gravity fed for some reason? Not enough flow? Maybe that's why we use them on modern cars?). Here is that thread https://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=3046901

I also saw one from kohler that claims to work with fuel pumps, but it looks like for a V twin based off it's size.

So what fuel filter and micron rating should I use to power a 7hp Tecumseh motor? Please help. and Thank you for reading!

 

[CLH]

OKAY! After scouring the web I think I've found a consensus. I also had to better understand micron ratings. One answer was on Amazon in a Q&A section about the 75 micron disc, screen element, fuel filter. The other answer was on a link to a forum in my post above.

Amazon answer:

"45 years in small engine repair the white b/s filters are for fuel pump systems and red are for non fuel pump or gravity systems.
By Mower Doc on April 28, 2017 "

I think I'll take his word for it, and try it. Sounds like he knows what he's talking about. 45 years!

That info is consistent with the post in the link I posted to bobistheoilguy.com, The post by jeepman3071 says:
"The red disk filters are for engines without fuel pumps. The white disk filters and clear filters with paper media are for engines with fuel pumps. I have seen scenarios where the paper media filters restricted flow in gravity fed systems."

So basically the Briggs red 150 micron isn't used with a fuel pump because the fuel pump doesn't need that much flow, the pump can overcome it. But a Briggs 75 micron is acceptable because it allows for enough filtration and flow which the pump can make up for. I imagine because it is pumping/sucking gas through the filter. Which isn't there with a gravity fed system.

Lower micron = smaller pores in filter = less flow
Larger micron = bigger pores in filter = more flow

You want a low micron rating for more filtration. You want a larger micron rating for more flow.

A gravity fed system needs all the flow it can get, that is why the red Briggs 150 micron filter is used for a gravity fed application. Whereas the 75 micron has a smaller pore size, but because the pump is able to overcome this (because it is a pump and it well, pumps) you might as well have more filtration if you are able to. That's why Briggs recommend the 75 micron rating for fuel pump systems.I think. That's also why you'll hear people say a pulse pump fuel inlet should still be lower than the fuel tank, so there is fuel always flowing through the filter into the pump - on top of the pump pumping gas through the system.
A paper element fuel filter also works for a fuel pump fuel system...one Kohler one was referenced at 51 micron. But the paper element filters don't seem to be recommended for gravity fed fuel systems. Too small of a micron rating I suppose. Paper filters mean not enough flow for a gravity system.

With the cheap Chinese 1/4 inch sintered bronze filter I purchased off of ebay, one I looked at before installing had the sintered bronze element inside separated from filter body. This would have allowed debris to flow by and I'm glad I noticed it before installing. I haven't really been able to find a good, name brand, version of the 1/4 inch small engine sintered bronze fuel filters...I did notice K&N made some. But most I see appear to be no-name chinese versions, and therefore I will avoid them as there seems to be no product quality control. I'd rather have something manufactured and recommended directly by a small engine manufacturer, and their mechanics which service their engines, even if it's a litter higher micron at 75 microns vs 40 or so for the sintered bronze or 51 for the paper. More fuel flow is probably a good thing anyways. Too high of a micron rating means less filtration though, and risks getting small bits of debris in the carb because the micron rating is too large.

It boils down to:

Use the Briggs red 150 micron fuel filter for gravity fed fuel systems.
Use the Briggs clear 75 micron filter if you have a pump fed fuel system.

You can also use a paper element type for pump fed fuel systems. I guess paper element type filters are not recommended for gravity fed fuel systems because too small of a micron rating, therefore not enough flow for good performance. But on a fuel pump fed system they work fine. With a paper filter, you can get lower or comparable micron ratings to a sintered bronze filter, like the Kohler one rated at 51 micron. For pump fed systems, you have more choice of fuel filters and it likely comes down to what is available and personal preference. Having too small of a micron rating only becomes important if you have a gravity fed fuel system. Don't go to low micron rating or you might starve for fuel with a gravity fed fuel system. If you have a fuel pump, don't go too high of micron rating or you might suck bits of crap into the fuel pump or carb orifices shortening it's life. I'm sure it IS possible one can also go to low of a micron rating with a fuel pump and starve it, but good luck finding a 1/4 inch small engine filter that is that low of a micron rating.

SHEEESH hows that for a first post? details, details, details
Still interested in hearing someones take on this! Let's talk 1/4 inch fuel filters. I'm game! LoL

 

[bob58o]

Great First Post!
If you are going to get a fuel filter, you might as well learn all you can about fuel filters.

I am patiently awaiting for EZ^2's response.

"--- -- ---- -------"

I've always used something like this from the small engine section at O'Reillys on my gravity fed systems. Never really had an issue, but I don't turn the engine 10k RPM and I don't hold it wide open for more than a minute or so. Never really thought about the filter that much, but never ran into fuel starvation either.

But it seems I should be using something like this...
The red one's description is for 7-15 HP and no Pump
https://www.lowes.com/pd/Briggs-Str...IeV5yYim7Fa021GOpnbKhuy-t3Y8Epz4aAoRREALw_wcB

 

[Nosandwich]

^^^^^^A match made in Heaven. You guys could form 10 paragraphs on how strike anywhere matches work.

We all want to learn, and to help, but ,REALLY? The average Joe only wants a little bit at a time.

You are free to do as you please, but IMHO, these "novel length " posts barely get scanned.

 

[mckutzy]

Bob...In that case ....Match(es) that is.... where do you stand.... strikeanywheres... strike on box, paper....windproof......

Lighters....Bic or Zippo....

questions questions......mmmmmm


Disqus

 

[Ebrownie]

^^^^^^A match made in Heaven. You guys could form 10 paragraphs on how strike anywhere matches work.

We all want to learn, and to help, but ,REALLY? The average Joe only wants a little bit at a time.

You are free to do as you please, but IMHO, these "novel length " posts barely get scanned.

I disagree with this. I only click on a thread if it looks informational or interesting to me. So usually, if I click on it, I’ll read the posts, no matter how long they are. But maybe that’s just me. And I didn’t know that about filters, so it’s good to know.

 

[Nosandwich]

Not saying the information is bad, or even necessary for some. It's just in this day and age.....well, encyclopedia salesmen are extinct.????

 

[CLH]

LOL yeah, I can admittedly be a bit long-winded! At least I'm get the point across I suppose. I'll try to be more concise in the future. And thanks for posting the link to Lowes! Yet another source confirming the red filters are for engines without a fuel pump.
I'll go with the clear / white Briggs and Stratton brand filter.

Ironically I forgot to add that I'm not saying paper filters only are for fuel pump engines, there are paper filters that work with gravity systems because I see them on dirt bikes and ATV's and such. I was specifically referring to the paper filters I posted that are meant to be used with pumps. I think fuel starvation is only a problem with high performance gas hungry engines that rev over 7,000RPM and such.
thanks

 

[Nosandwich]

Bob...In that case ....Match(es) that is.... where do you stand.... strikeanywheres... strike on box, paper....windproof......

Lighters....Bic or Zippo....

questions questions......mmmmmm


Disqus

Now you've done it!!! Get ready for the history of fire!LOL

Ever wonder why Bob has trouble with women??? They don't get a chance to talk!

---------- Post added at 05:39 PM ---------- Previous post was at 05:32 PM ----------

Bob...In that case ....Match(es) that is.... where do you stand.... strikeanywheres... strike on box, paper....windproof......

Lighters....Bic or Zippo....

questions questions......mmmmmm


Disqus

Now you've done it!!! Get ready for the history of fire!LOL

 

[bob58o]

Bic for sure.

Matches and zippos are not optimal when using functional art.

 

[Nosandwich]

Bic for sure.

Matches and zippos are not optimal when using fart.

Hmmnnn

 

[mckutzy]

I prefer flint and steel myself...... Thats how I light my pipe, and my matchlock.....Well... I dont smoke and shoot.... but one or the other....

 

[ezcome-ezgo]

Who sells strike anywhere matches anymore? You'll burn your eye out with them things.

 

[Nosandwich]

I actually found some! Wasn't easy....

(Little consumer tip: those "Strike on box" matches don't work on just any box.)

 

[ezcome-ezgo]

Must have got them off the notorious match black market.

 

[landuse]

Who sells strike anywhere matches anymore? You'll burn your eye out with them things.

Camping goods stores often have them