Pressure washer problem

[r.bartlett]

Chaps

I have a Neilsen petrol PW - packed away all good last year this year... Not so good.

Firstly it wouldn't start. Traced to a blockage in the jet -cleaned and it now runs.
However now every time you pull the trigger it stalls.

Not sure how these things control but if anyone can assist that would be cool

TIA

Richard

 

[Pigeon85]

Have you put in fresh petrol? If not then drain out and clean the tank.

 

[Burnerman]

When the lance trigger is pulled, the engine immediately has to deliver more power, so the engine governor opens up the throttle on the carburettor.
I'd need to satisfy myself that the engine was able to run fast on its own first - is there a lever nearby to increase the engine speed?
The next thing is to ascertain that the pump internals aren't siezed....with the engine off and the trigger pulled, does low pressure water come out of the lance?
Caution - its not a good move to allow these engines to run for long without pumping water so do your test with the water supply turned off.
John

 

[r.bartlett]

When the lance trigger is pulled, the engine immediately has to deliver more power, so the engine governor opens up the throttle on the carburettor.
I'd need to satisfy myself that the engine was able to run fast on its own first - is there a lever nearby to increase the engine speed?
The next thing is to ascertain that the pump internals aren't siezed....with the engine off and the trigger pulled, does low pressure water come out of the lance?
Caution - its not a good move to allow these engines to run for long without pumping water so do your test with the water supply turned off.
John

The machine has a tortoise and hare setting. It runs cleanly on both. It will chugg along for 4 minutes but as soon as you pull the trigger the engine dies..

The trigger will let water flow through when off. If the pump is seized then would the engine turn over? I don't see a clutch mechanism so I guess it's direct drive?

 

[Burnerman]

These machines have a plate cam mechanism, that as it spins, compresses 3 or 4 spring loaded pistons in turn.....these force the water into a valve chamber and then out to the lance.
There is a possibility that if there is a valve problem then the water can't escape, and therefore stalls the engine.
The valve chamber is held on with 4 screws.....if its the machine I'm thinking of, this chamber is available separately. Beind it the pump chamber has 4 bolts. If you dismantle anything, the pump chamber will be full of oil.
Personally I'd be inclined to strip the pump and see how the engine behaves without it connected.
Post a photo of the pump and I'll see if I recognise it!
John

 

[Norcon]

I have a Neilsen petrol PW - packed away all good last year this year... Not so good.

Maybe the frost has bursted it.

 

[r.bartlett]

These machines have a plate cam mechanism, that as it spins, compresses 3 or 4 spring loaded pistons in turn.....these force the water into a valve chamber and then out to the lance.
There is a possibility that if there is a valve problem then the water can't escape, and therefore stalls the engine.
The valve chamber is held on with 4 screws.....if its the machine I'm thinking of, this chamber is available separately. Beind it the pump chamber has 4 bolts. If you dismantle anything, the pump chamber will be full of oil.
Personally I'd be inclined to strip the pump and see how the engine behaves without it connected.
Post a photo of the pump and I'll see if I recognise it!
John

http://www.tooled-up.com/artwork/ProdPDF/PCM2500SP_P.PDF

http://www.tooled-up.com/artwork/ProdPDF/PCM2500SP.pdf

 

[Burnerman]

Its not a pump I'm familiar with - sorry! However, I reckon the fault is in part 39, the unloader valve which is keeping the internal pressure too high.
John

 

[r.bartlett]

Its not a pump I'm familiar with - sorry! However, I reckon the fault is in part 39, the unloader valve which is keeping the internal pressure too high.
John

I'll give it a go at the weekend..

tia

 

[foxhole]

Lean oil mix can cause it too die when calling for power.

 

[Burnerman]

Good theory Foxy and correct - these machines have 4 stroke engines though, OHV usually but some are SV......governor control is so much more dependable with a 4 stroke engine.
John

 

[r.bartlett]

Did the sprippy down thing and all and found nothing wrong.

After much trial and deliberation it seems the engine won't run properly with the choke fully off. As soon as the choke is turned past 2/3rds the engine dies.

Run it at just over half choke and she purrs like a kitten till the lake pipes roar...