Hello
I am hoping someone can tell me what I have done wrong. I finished setting up my trailer and have run into what I hope is a small problem. I have the Honda Gx690 8 gpm comet pump 24 hp. It starts fine but when I release the trigger on the gun the motor shuts down. I am hoping someone has seen this problem and can tell me what I have done wrong. Please help! Thank you in advance for your help.
AJ
Sounds like an unloader failure
Even on a brand new machine?
Did you properly set the unloader?
When exactly is it dying? Are you squeezing the trigger when starting it and instantly let off the second it starts? If so, let it warm up for 30 seconds or so before letting off the trigger.
Brand new as in this is the first time you used it? Or used several times? Regardless, it could be the unloader failed.
Honda doesn’t make a 24hp motor but sounds like unloader
Agreed in the 24hp. Give more information and we will try to help all we can😎
If this is the first run, you may have something plumbed wrong. Check you unloader plumbing. Every port on it should be labeled, in, out, bypass… Or possibly you have the unloader set to a higher pressure than the engine can produce.
I hold the trigger while starting. It starts fine. It continues to run as long as I keep on the trigger. As soon as I release trigger it stalls instantly.
I wasn’t aware I had to set the unloader. I will continue to research. It is a brand new machine purchase new. Honda gx 690 3500 psi 8 gpm cold water machine. Never used.
Thanks
Definitely something plumbed wrong, or you need to set you unloader. It may be cranked down beyond that Honda’s HP.
8@3500 needs 25.4 HP, and you don’t have that, because the biggest Honda makes is 22HP these days (in the US) So I’d start with back in the unloader waaay down, check the problem again, if it keeps running, the set up your unloader properly. The most u will ever get under perfect conditions is 3000psi.
BS - I get 3600 out of mine all day every day which is the exact spec of the TSF 2021 pump with at least 21 hp at 1750 rpm’s.
I apologize if I offended you and made you call BS on me, buuuuuutttt…
I’ve been told/ read every single day since the first day I found this forum that THIS IS 100% FACT. I do not agree with it, because I have myself proven that math WRONG. I get 3900ps @ 5 gallons a min on 2 different Gx390’s, and 6 gal a min @ 3000psi with the 3rd. I know this for 100% I’ve checked it over and over! The 1100 rule seems to be the Gospel around here, but it’s not a fact. The only reason I posted that is because if I would’ve said anything different someone would have swiftly corrected me!!
Just a little aside, CAT pumps states this equation as gpm x psi / 1450 = required HP. Not
1100 as most speak of. If you use 1450, all the math works out for my machines, and yours! 
BUUUUTTTTT… when in Rome…
Most engines are not based on stall HP there based on duty cycles. The general rules of
1100 gas engine
1250 Diesel engines
1450 electric motor
1700 hydraulic motor
Are generally rated @ 50 percent duty cycle so you don’t over work the power plant.
This is only a general rule not FACT. Since all manufacturers are different.
Ironically with combustion engines gas or diesel the main hp rating is not necessarily based on power but commonly base on the engines ability to effectively remove the heat created .
And to one up that, most manufacturers now rate is FT/LB of torque nowadays! . But in our applications HP is more important that torque.
Most people don’t understand HP anyway. HORSEPOWER is just a math equation based off torque and RPM. Torque is what gets you there, and HP is what keeps you there, that’s how it was explained to me years ago.
RPM x TORQUE/ 5252 = HP
No sir. Still trying to figure this thing out. I may have to take it to some more experienced on Monday. This sucker fire right up and runs strong as long as I’m on the trigger. Shuts off as soon as I release trigger. I’m watching YouTube videos and reading owners Manuel to no avail. I’m a bit disappointed, but I will share the answer once it’s found. Thanks for your help.
Did u check all the plumbing? Did I try loosening the unloader spring?
I loosened unloader spring all the way out. Same result
I’d be happy to try and video my set up to let you look at it.
