Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length.

[muduck]

I've had the engine for 3 years, & can't get the water pump working ...tried just about everything I can think of, what I need is to talk to someone, say on Skype, who has one.
send me a message if you can help..Thanks.

[flashtwo]

Hi Muduck,

One very useful and cheap device for checking pumps performance is a length ( about 20cm long) of clear silicon rubber tube fitted on the inlet line of the pump.

Make a very small pin-prick hole in one side of the tube about half way along and orient the tube to the horizontal.

With the pump running, stretch the tube which will open up the hole and allow a bubble of air into the pipe and then release the tube.

If the pump is performing correctly then the bubble will move along  the tube in one direction steps. If the inlet non-return valve is passing then the bubble will travel to and fro. If the outlet non-return valve is passing then the bubble will hardly move, but it is all a matter of how much it is passing as to how the bubble behaves.

To be clever, knowing the internal tube diameter and length of each "bubble step", you could calculate the actual pump capacity.

Have you tried tapping the valve seats with a sacrificial ball? The brass seat should then be reformed and then sacrificial ball replaced in case it is damaged.

Have you ensured there is no air in the pump?

good luck.

Ian.

[KBIO]

Good evening;
I agree with Flashtwo: the silicon hose is the simpliest and more reliable  help.
On my side, if I can help & to make the things "harder"(?), I choosed to have a sight glass indicator.
Step one : prime the device by pumping some water from the top plug. No air between the bottom of the sight glass and the engine suction.
Step two: ensure that the suction pipe is full with water from water tank (or below the boat) , but it is not madatory.
Step 3: run the engine and check the drop coming down at each pump stroke. It has to flow.
To control the flow rate supply, use the by pass!
 But the best is still to adjust the pumping rate according to the engine comsumption. By pass is not accurate and steady.
http://youtu.be/yHO_9hoy-1E
http://youtu.be/yHO_9hoy-1E

Concerning the Monahan pump, it is generally made to supply a small boiler so the rate is very low.
Here is an example of what I use.
By sliding down the end of the excentric, I modify the stroke length.

Hope I help.
Cheers.

http://modelismenavalradioc.nouvellestar6.com/c9-modelisme-bateau-a-vapeur

[muduck]

Thanks guys, will take this to the workbench tomorrow & see if I can nut it out..