Blessings!
Does anyone here know if the pulley has a direct relationship to volume?
I have rebuilt and old machine which has a TSF 2021 pump(General)
Replaced the engine with a honda 690, rebuilt the pump, put in a new coil and unloader
Pressure is great but am still only getting about 6.6 gallons a minute instead of about 8.5gpm
Am using a separate generator for the burner so that all power from the engine goes to the pump
Am running out of ideas
Any help would be greatly appreciated
Sounds like you may be turning less RPM than needed with that pump. See the alternate specs on your pump on the attached. If you’re only turning 1450, then you’re about right. You may just need a different sized pulley, but someone smarter than I would have to help you get right one. You could probably call Russ Johnson at Southside and he could help you.
The part number I gave him is for the sheave on the 690. If he switched motors, I’m thinking that may be the problem. No one gives pertinent info when they won’t something diagnosed though.
Are you testing volume at full pressure? The gx690 is 22 hp, so you won’t get full gpm at pressure. Depending on which formula you use, you would need either a 25 hp or 27 hp engine to make full specs. (I would go with 27, but Honda doesn’t make one)
Edit-the base calculation doesn’t factor in friction loss in the hose, so you have to account for that as well.
