720 experts

[mwells 8]

Hi guys I picked up a 720 and found it had a bad fuel pump. The inlet fitting on the carburetor has a port going back to the tank for a return as well as the one that goes into the carburetor to feed fuel to it. Just curious if this is factory and if so why does it have a return on it? I'm new to the powermax series so sorry if this is a dumb question. Thanks in advance!

[phillobbezoo 139]

I think at idle the pump puts out more fuel then the tractor needs so it runs it back to the tank or that's what I've always thought.

[phillobbezoo 139]

And by the way it does matter what way there hooked up, if you have them backyard you will be putting fuel in it all the time. The metal lines in the tank are different lengths the return line doesn't go as deep in the tank as the suction line. My brother had a 720 that always started to run like crap when it got to about half a tank if we topped it off it ran fine again. Took me awhile to figure it out, a lot of curse words and after pulling out most my hair I noticed the lines were different then my 9020

[mwells 8]

Ok thanks for the advice!! I can imagine how that would drive you nuts! Lol just curious why this gas engine has a return and Kohler's and Briggs engines don't.

[midnightpumpkin 83]

I suspect the reason for the fuel return is to prevent vapor lock as well as reduce pressure to the carburetor. If you take the fittings off of the fuel block you will find a small orfice in the return line port. The orfice is there to provide a small amount of pressure to the carburetor inlet.

If you install an electric fuel pump, highly recommended, keep the return line in place.

John U

[isetta 50]

Mike, check out the recent post best fuel filters. Scroll down for a picture of the hose routing on a 9020 with oem mechanical pump. I have not yet gone electric. The rebuild kits were 15 bucks a few years ago when I did my last overhaul

[mwells 8]

Thanks for the information John! You read my mind because I am wanting to go to an electric fuel pump. I'll check out the photos thanks!!

[720nut 4,225]

Mike, I can't post any pictures right now but if you do some checking I have pictures of my 620 electric pump setup posted on here (memory not real good) as to where.

[Marty-MN 0]

Even though you have a fuel return line if you go electric make sure you get a low pressure pimp.

[720nut 4,225]

www.bbsfuelpump.com

square pump, comes with fuel filter and all fittings needed to install part #7782 on box is low pressure (can't post pictures)

Facet # 40104 2-4 lbs was 21.99 on ebay when I bought mine.

[powerking_one 0]

quote:Even though you have a fuel return line if you go electric make sure you get a low pressure pimp.id="quote">

id="quote">

I guess that would make work easier for the older carbureted "girls"

Sorry, I just couldn't resist. (LOL)

Tom (PK)

[isetta 50]

That's a good one Tom. I am sitting in my car at McDonalds on a tractor getter trip reading your post and laughing out loud.... : )

[phillobbezoo 139]

Now what are you getting Rick, is it another Brantley

[720nut 4,225]

I've often wandered the same trying to corner the market?? I guess I must live a very shehtered life as all I ever see are the ones everyone wants a fortune for, do they really sell at those prices?

Mcdonalds on a tractor getter trip?

[isetta 50]

I just always seem to end up in Ohio eating at McDonalds, and that one from Tom about the old carbureted girls and their electric pimps just hit the funny bone: ). Oh and yes I dragged another Brantly home but I swear this is the last.......

[720nut 4,225]

Heard that one before

[isetta 50]

Of course then we change our minds when a deal is in front of us : )

[Talntedmrgreen 1,978]

I pack PB&J...I stop for fuel and to pee, and only when I need to do both at the same time. If the GPS isn't telling me I'm averaging 66mph, I pick up the pace! Gotta maximize my BS'n time!

[isetta 50]

I am with you on that Josh. This gentleman wanted to meet at Mickey Dees and I am cool with that. Heck I was the one carrying cash. Driving on the way down it was 73mph and leftover chicken wrap! Woo hoo getting down the road though. 3rd time to Columbus in 3 months : (

[Itsmechuck 6]

I put an electric fuel pump on mine a few years ago and it works great! The hardest part for me was finding enough space to install it without "butchering" anything. Also fabricated a metal plate to put over the hole where the mechanical fuel pump was bolted on.