Gas Powered Roof Pump Info Thread

I’m starting this thread as a spin-off of the info @Racer posted about his gas powered pump on that hotel access thread. (All you thread derailers, take a lesson from this!!:stuck_out_tongue_winking_eye:)

I’ve been wanting to set up something other than my 12-volt system for several years now, and I don’t know much about the gas powered pumps. I like the thought of an aodd, but the expense and the amount of space they take up are turn-offs for me.

I’m interested in setting up a small skid I could keep in a pickup bed, and a gas powered pump seems like a good candidate for that.

My biggest questions are:

  • How badly does it foam when recirculating?
  • How adjustable is the output? (Can you go from a fine mist to a flood just by changing nozzles and/or feathering the trigger, or do you have to adjust other things too?)
  • Udor’s chem pumps don’t seem to have the best reputation for use with SH… @Racer With the pump that came on your setup, what maintenance is required on the pump itself, and do you foresee any major pump component failures? (I assume you would plan on replacing the pump at some point, but I’d hate to have one start leaking or something like that and rot a pickup to pieces)

Thank you, in advance, for the info!

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I do not own one, but when I was in Nashville last winter at the power wash store event, I watched Paul take about 8 minutes to get the pump primed, that was an instant turn off for me.

Did he say if that was the norm? Russ had one in Nashville a couple years ago at a uamcc event and it fired right up and was pretty impressive for soft/roof washing.

Interesting…it seems like a properly located check valve would solve that, though…Maybe he didn’t set it up correctly?

I honestly don’t know, he had it just circulating back to the tank, and said it takes a few minutes to prime and I stood there for a long time waiting lol ( 8 minutes)

That’s good to know. Thanks for the info!

Don Phelps of All Seasons Exteriors out of Orlando was/is kind of the roof guru back 10-15 years ago. He ran the John Blue Udor pumps. They have 5.5 or 6.5 HP Hondas on them. He used to buy new ones each season and sell the 1 year olds cheap. I haven’t talked to Don in awhile but he is still around. He’s a good dude and don’t think he’d mind helping you out if you can reach him…

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Paul may have been demoing a booster pump. The gas one primes just like a pressure washer, Takes like 5 seconds and you just want to make sure no bubbles in flow before you switch pump out of bypass mode or that can hammer your pump.

Doesn’t foam at all when recirculating - that’s using 1oz of snotmenade/gal.

Yeah, the Udor pumps don’t last or at least didn’t, last time I checked with these type of systems. I’ve got the AR and I’m happy. Been using about 10months and the only thing I’ve had to do is replace an oring, and it was probably my fault it started leaking some… There are certain order of steps you go thru when starting and shutting down, mainly making sure it’s in bypass mode when you do either.
The pumps are really pretty simple to work on. Remember they’re pretty low pressure. Heck, 40% of the things you just pull a little pin out or unscrew with your hand. The pumps by themselves are like about$1000, but not really sure why you’d really ever need to replace the whole thing unless you somehow cracked the exterior housing.

Compared to the noise a large compressor makes and that chugging sound, these are pretty quiet. A honda 200 running 1/2 throttles, so not noisy at all…Other than the pump being able to handle SH, it’s basically the same setup that every yard spraying service in the country uses and you know how much they run theirs all the time. Heck they probably put more hours on theirs in a month then we would in a year.

You can buy a skid mounted one with tank and all, but that limits you to batch mixing. So you would have to carry spare chems or whatever to replenish it. With the flow you can flat go thru some mix if you’re not careful.

If it were me putting in a truck bed, and I ran mine out of my truck bed for several months, until I decided where to put on trailer, I’d just throw me a 275 tote in back of truck for water, mount a reel on it or somewhere, put your proportioning system mounted on side of tote, put a drum for your bleach and you can set this thing anywhere. I can pick it up by myself, doesn’t weigh 60 lbs. They’re pretty light. .

Just use your nozzles to throttle down flow. Doesn’t hurt it, because it’s a bypass system.

Hope this answers some of your questions. Heck, you’re 45 min away. Drive yourself down here one day and play with it.


LOL, On my trailer I have this, the 8,5gpm pw, 2 12-volts and a 4gpm machine. Realistically 4 people could work off this trailer at once and be productive if you could keep enough water in the tank. 1 12v and the 4 soaping and the 2 big ones rinsing. Of course I’d need 2 more reels to do that. :grinning:


How are you running the gas pump with. Proportioner? A long bypass loop to the inlet?

That’s good to know, I wouldn’t mind a gas system, for some reason I’ve had it stuck in my head that they took to long to prime lol

I’ve got a separate batch mix tank because when I got mine, using a proportioner wasn’t being done because of the bypass requirements and also because there weren’t any hi-flow proportioners. Now they do have and people have figured out you can have an internal bypss by using a longer hose to let it cool down, plus these pumps don’t generate nearly the heat anyway. I had heard that it could run about 10 min anyway w/o overheating but sometimes that’s not long enough if say you’re having to move ladders around etc. So I think there are enough people using now with the extra hose that it seems to be working… Plus now there are proportioners with more capability than we had a year ago.

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When I had a gas powered setup the bypass created lots of suds when it returned to the tank. Solution… install a bulk head on top of tank then thread a 1/2 or 3/4 pvc pipe to bulkhead. Make sure the pipe is a few inches from the bottom of the tank. No suds to worry about.

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