[email protected]
Starting Member
- Total Posts : 8
- Scores: 0
- Reward points: 0
- Joined: 2021/12/08 13:47:55
- Status: offline
WB20XT water pump fluctuates in RPM and pressure
In fire fight mode, the engine runs strong for 15 -20 seconds producing high pressure. Then the RPMs decrease for about the same interval, producing a significant loss in flow and pressure. Any ideas?
|
[email protected]
Starting Member
- Total Posts : 8
- Scores: 0
- Reward points: 0
- Joined: 2021/12/08 13:47:55
- Status: offline
Re: WB20XT water pump fluctuates in RPM and pressure
2021/12/08 16:22:00
(permalink)
I should add that this pump system is brand new
|
SRTsFZ6
Super Member
- Total Posts : 2084
- Scores: 74
- Reward points: 0
- Joined: 2018/11/18 07:20:58
- Status: offline
Re: WB20XT water pump fluctuates in RPM and pressure
2021/12/08 17:17:35
(permalink)
I would disconnect the low oil sensor and see what happens...
When they fail, it usually KILLS the ignition, so it probably isn't the issue...
|
[email protected]
Starting Member
- Total Posts : 8
- Scores: 0
- Reward points: 0
- Joined: 2021/12/08 13:47:55
- Status: offline
Re: WB20XT water pump fluctuates in RPM and pressure
2021/12/09 06:43:56
(permalink)
Yes, the Owners Manual states that the low oil sensor kills the engine. I'm wondering if it could be the carburetor adjustment. There's a screw there that maybe I could adjust, though you would think that it would be set properly on a new unit (?).
|
SRTsFZ6
Super Member
- Total Posts : 2084
- Scores: 74
- Reward points: 0
- Joined: 2018/11/18 07:20:58
- Status: offline
Re: WB20XT water pump fluctuates in RPM and pressure
2021/12/09 07:20:54
(permalink)
I'm not sure what "carb" screw your talking about as the EPA pretty much has no more adjusters on the carb except for an idle adjuster screw..
Did the issue start RIGHT AFTER the new pump was installed?
|
[email protected]
Starting Member
- Total Posts : 8
- Scores: 0
- Reward points: 0
- Joined: 2021/12/08 13:47:55
- Status: offline
Re: WB20XT water pump fluctuates in RPM and pressure
2021/12/09 08:14:47
(permalink)
OK, I see a black screw head, phillips, on the carburetor body that is about 1/4" diameter. But I don't what it's for; maybe just an idle adjustment like you say. (I'd actually hope so because I always feel antsy messing with the carb adjustments on my leaf blower.)
When I first tested the pump I had set it up with the suction hose in a garbage can and a wide open discharge. It sucked the water out of the can really fast, and I didn't notice any change in rpms or flow rate. When I set it up with the suction hose in the river behind my house, and the full 50' discharge hose, I experienced the cyclical behavior. At the low ebb part of the cycle the output was really low ... useless for an actual fire situation. Then it would come back strong and shoot far enough to reach my house and some of the surrounding trees. If I can't eliminate the low-ebb part of the cycle I wouldn't trust it in an actual fire.
|
SRTsFZ6
Super Member
- Total Posts : 2084
- Scores: 74
- Reward points: 0
- Joined: 2018/11/18 07:20:58
- Status: offline
Re: WB20XT water pump fluctuates in RPM and pressure
2021/12/09 09:58:25
(permalink)
Sounds like your sucking air possibly from the line..
Also, that .25" screw IS the idle adjuster.
|
[email protected]
Starting Member
- Total Posts : 8
- Scores: 0
- Reward points: 0
- Joined: 2021/12/08 13:47:55
- Status: offline
Re: WB20XT water pump fluctuates in RPM and pressure
2021/12/09 14:49:20
(permalink)
The behavior I was seeing is well explained as an air leak in that the interval of the low-flow to high-flow was so repeatable. At high flow the leakage continues until enough air builds in the system to interrupt the prime. Then it reprimes and flows full. Then repeats.
Current status: I checked the 2" cam lock male adapter provided with the hose pump kit and I did find it to be loose; maybe 1/2 of a turn or so. I tightened it up and retested the system with the suction hose in a garbage can, filled to the top and with a garden hose adding water. The system pumped strong for the duration of the test and, although it sucked the water down very fast, I believe that the duration exceeded the time interval when I was experiencing the cyclic behavior. My wife agrees. So, I'm pretty optimistic. A proper test will be tomorrow, or the next day. The system is hard to set up using the river for water supply.
|
[email protected]
Starting Member
- Total Posts : 8
- Scores: 0
- Reward points: 0
- Joined: 2021/12/08 13:47:55
- Status: offline
Re: WB20XT water pump fluctuates in RPM and pressure
2021/12/12 12:14:49
(permalink)
I tested the pump in the river today and saw that the pump ran strong (high pressure) for several minutes. I thought that I had indeed solved the problem. But then it started fluctuating again with the low flow, low pressure part of the sequence lasting longer than the high pressure part of the sequence. As if it was having difficulty reestablishing the prime.
I don't see how the heavy green inlet hose could be leaking. As of now, the system is totally inadequate for use in a fire situation and I am out of ideas. Would it make sense to appeal to the crew at Jacks Small Motors for advice?
(I don't know if I was clear in my earlier posts, but this is a brand new system and it is useless for it's intended purpose.)
|
SRTsFZ6
Super Member
- Total Posts : 2084
- Scores: 74
- Reward points: 0
- Joined: 2018/11/18 07:20:58
- Status: offline
Re: WB20XT water pump fluctuates in RPM and pressure
2021/12/12 12:43:03
(permalink)
If it's not working correctly, I'm sure they'd take it back...
|
[email protected]
Starting Member
- Total Posts : 8
- Scores: 0
- Reward points: 0
- Joined: 2021/12/08 13:47:55
- Status: offline
Re: WB20XT water pump fluctuates in RPM and pressure
2021/12/13 10:21:04
(permalink)
I had some tests planned this AM, first without and then with the pressure nozzle; both the vacuum hose and the discharge hose were submerged in a garbage can. I didn't get far into my planned tests, however, when the pump lost prime and would not re-prime. It's as if it has now died. (The pump, not the engine.) I've sent a message to Jacks Small Engines for direction.
|
SRTsFZ6
Super Member
- Total Posts : 2084
- Scores: 74
- Reward points: 0
- Joined: 2018/11/18 07:20:58
- Status: offline
Re: WB20XT water pump fluctuates in RPM and pressure
2021/12/13 13:18:03
(permalink)
Yep, sounds like the pump was assembled late on a Friday, by a disgruntled employee who missed lunch...
|
[email protected]
Starting Member
- Total Posts : 8
- Scores: 0
- Reward points: 0
- Joined: 2021/12/08 13:47:55
- Status: offline
Re: WB20XT water pump fluctuates in RPM and pressure
2021/12/14 07:38:08
(permalink)
Jack's has not responded to my message (they say the message approach is for questions about the web site, so I'm not sure I'm in the correct venue). I went to Amazon to start a return and it was accepted. To print a return label I was sent to a page with the instructions for a return to Jack's and read the following: "Any product returned to Jack's Small Engines must be new, unused, complete and marked with a valid RMA number." I don't satisfy the 'unused' requirement so I will call them today and find out what they want me to do. I'm posting this so that others will be aware of Jack's requirements.
|