[vhgmcbuddy]

I have found the flywheel cowling and the numbers are

06311HSB40/41212
6138787

Hope this might date the engine

[vhgmcbuddy]

Thanks Charlie.

I had another look yesterday and found the fuel switch. It’s not sparking so I’ll have to have a closer look later.

Once I get it working – in your experience do you think this machine could be used to go up slight inclines on clay? Obviously I would reverse up the slopes but having not used this sort of equipment I didn’t know whether it was purely for flat work. I’ve dug a large pond and the edges could do with some serious squashing.

Graham

[vhgmcbuddy]

Thanks to you both – you know your stuff, great.

It certainly looks like the MK25 from a brief bit of research – thanks very much. Looks most likely to be a Stotthert & Pitt too – I shall see if I can hunt down the exact model and details – thanks very much.

Cheers for the advice regarding the choke. Forgive my naivety but once I get it started – how would you normally turn it off? There isn’t an apparent switch in the electrics and so I assumed starving it from air was the answer – it appears not.

Graham

[vhgmcbuddy]

Also , thoroughly check your inlet manifold gasket.

Good point.but don’t stop with the gasket, put a straight edge across the flange – they are quite prone to bowing from over tightening.

[vhgmcbuddy]

Does seem that you’ve dealt with most of the likely candidates! One test is to hold the carburettor throttle spindle steady of even screw the idle stop screw fully in to stop the spindle moving. If the hunting persists it is a fuelling issue. If not, maybe try a new spring.
Have you tried fully loading the drum to make the engine “work”? The reason for asking this is that way back when the 5HP version of your engine with a similar tank, throttle and governor set-up was fitted to the Atco 24 lawnmower some machines had a”hunt at idle” problem but the machine was fine when under load. The cure then was to fit an additional very light governor spring to steady the carb spindle. Fairly sure that I still have the Briggs Service Bulletin somewhere if needed!

[vhgmcbuddy]

Thanks for that. It’s had a new diaphragm, the pickups are spotless and the carb has been ultra sound cleaned. The valves were also reground, decoked, new plug,electronic ignition coil plus new rubbers on the carb pulse pipe fitted.
Was only considering a governor after the difference it can make to Hondas, but I’ll listen to your advise, perhaps just try a needle and seat first.

[vhgmcbuddy]

Most (but not all) Briggs hunting issues are to fuel starvation resulting from gumming in the carburettor and / or weak fuel delivery due to a hardened pump diaphragm. Things to look at are partial blockage of the filter screen on the bottom of the long pick-up pipe, ditto the short pipe, hardened diaphragm and general varnish / gum in any accessible carb passages.
Use the BS Model, Type and Code numbers to get the correct diaphragm – guessing 270026. Unlikely to be the gov spring unless it shows signs of having been mauled about!

[vhgmcbuddy]

I’ve tried brick acid in the past but it doesn’t seem to work very well. I’ve heard it suggested by some that it may be down to the lime in the concrete neutralising the acid?
I’ve got a video of cleaning out the inside using metal and bricks. The engine is hunting a bit so I was thinking about ordering up a new needle and seat plus a governor Spring as I can’t quite get it to smooth out, unless anyone has any other ideas?

[vhgmcbuddy]

Just got the tedious job of removing all the old concrete.

Can you not use the “brick acid” from the builders’ merchant – or is that a no,no?

[vhgmcbuddy]

Managed to make a bit of progress with this project. The engine is sorted and the drum is almost straight. Just got the tedious job of removing all the old concrete.

Attachments:

1. 
2. 
3. 
4. 

[vhgmcbuddy]

I’ve run quite a few of these engines on gems, and never had an issue, would it be worth obtaining a second hand valve out of an original engine and see if it lasts any better?

[vhgmcbuddy]

Not aware of it burning oil excessively.

Thanks for the offer, but it’s not a Model 5, it’s a UCZ.

[vhgmcbuddy]

Yes, but no luck sadly

[vhgmcbuddy]

While you may not need the type number for your immediate problem it might be useful for other issues such as identifying the ” structure” behind the pulley which is not a standard 8000 series fitment – an additional crank support bearing? Also, the end of the crank would appear to be splined. I wonder whether that engine originally had a factory fit reduction box?

[vhgmcbuddy]

If its a 3hp engine then the five digit model number will start with an 8.At a guess the full model number may be 80303.The engine,s type number is not really required as the carburettor is a common “pulsa-jet” type and any parts you need are easily obtainable from either your local B&S / garden machinery dealer or on-line.

[Author]

Posts