Thwaites Tusker Dumper PH2

[briandshepherd]

Hi Guys,
Have recently purchased a 1983 Tusker dumper with Petter PH2 that has been standing idle outside for a long time, but it still appears to be in reasonable condition.
Fuel system had water in it and have bled pumps and injectors until clean fuel and had it running briefly OK. Have since fully cleaned out fuel tank and fitted new Fuel Filter as original was fitted without spring and washer underneath element and wasn't filtering anything. Have bled both pumps and injectors again and can get it running with much cranking, but only on one cylinder. Injector furthest from flywheel appears to have no fuel to it now despite bleeding OK previously, and fuel pump bleeds from bleed screw OK but now supplies no fuel out of top when primed manually. As it has bled before at injector, I am assuming there must now be some blockage in the fuel pump, and before I start to take it apart I would ask if anyone has an opinion or any advice about the PH2 engine injection system.
Thanks in anticipation of your help
Brian

[FOWLER MAN]

Hi Brian,
Theres no way you will have a blockage in the pump.
It sounds to me as if the delivery valve is not seating properly in the offending pump.
Remove the injector pipe from the pump and screw out the delivery valve housing nut from the top of the pump.
Remove the delivery valve spring and you should be able to remove the valve plunger from under the spring, if it is stuck you may have to use a snipe nosed pliers to pull it. Just flush it through with fuel, make sure its clean, free, seating properly and reassemble.
If that does'nt work let me know and we can look into it further.
There's loads of info. on setting up and timing these pumps on here somewhere which I posted previously.

Fred
P.S. You can download a workshop manual on the PH2 free from http://www.winget.co.uk

[briandshepherd]

Hi Fred,

Thanks for your advice, and I now have downloaded the manual also.
Have cleaned out the delivery side of the pump and the valve just popped out easily when I primed it.
All cleaned out and reassembled now and bled again, but not managed to get it to start yet.
Engine is not as slack as a number I have seen before, and as it is fitted with hydraulic tip from new, you are cranking a hydraulic pump each time you crank it ( I suppose the same as the tusker digger) and you really need an extra hand to drop the decompressor before it stops again.
I wonder if it is feasible to crank it with a power tool or air tool because electric start looks to be an expensive conversion.
I will have some help over the weekend and will try again to get it running properly and will keep you posted.
Thanks again for your help.

Brian

[briandshepherd]

Hi Fred,
A Happy New Year to you ...
Have had it running today after a good crank over but it is still only running on one cylinder.
I am wondering now if it has only ever run on one from the start as it only ran initially for a few seconds before it stopped.
Despite cleaning out the delivery valve there is still very little fuel coming out of the pump, either priming it or when it is actually running, which probably explains why that cylinder isn't firing.
On close inspection it looks as though this pump might have been taken off before at some time and I don't know if pump timing will effect fuel delivery if it is not correct. Will have to check the timing out and then perhaps take the pump off if that doesn't work.
Does anyone know if pump failure is a common fault, or is it likely to be adjustment ?

Brian

[manx674]

hi, I had similar trouble with my PH2, turned out to be a broken injector pump spring, the spring was coiled up inside each other, so was only getting a tiny stoke, overhauled both pumps and fitted new springs, all sorted

[briandshepherd]

Hi Adrian,

Good point ...
My next step is to start checking out the basics of the injection pump, and of course if the spring is broken then it is not likely to pump out much fuel is it ?
I am not new to engines, but this is my first involvement with the Petter PH2 so any advice I can get is very much appreciated.
Will post my findings if I get to the bottom of it.

Brian

[pikeydal]

anyone got any photos of the brilliant thwaites tusker digger dumper