[Honeymonster]

Hi,

I'm new to the forum but need a bit of basic advice for a pre 1965 Mountfield M1. I've done a bit of reading on the forum about this engine courtesy of some advice Gwiz gave back in 2007 but i've got a couple of questions relating to oil/servicing.

I've absolutely no experience with engines of any size and given some comments about having to make sure there is enough oil in the engine from posts in 2007 I'm a bit concerned because i've just purchased one off ebay and just want to give it the best start possible.

The machine appears to be in great working order, the guy started it up and showed it me working but I was wondering if it would be a good idea to service it a bit before I use it. Mainly, do I need to be concerned about checking the amount of oil in the crankcase? If so where do I put the oil? Do I need oil for the engine and gearoil? What type of oil do I need to use?

Any clarification would be greatly appreciated, must admit i've researched this model but can't find a manual and I am beginning to confuse myself!

Thanks

Honeymonster

[Honeymonster]

Told you I was getting confused, it's actually a 3.5hp B and S engine.

Honeymonster

[Gwiz]

I'll help if I can
I can't remember what comments I made back in '07, but if it was regarding an Aspera engine and oil, it would be something along the lines of "Check the oil as often as you can, as these engines like to through their con rod through the side of the engine casing if you don't"
As regards your Briggs engine, I expect that it will take around 1 pint of oil (most of those fitted to machines of that vintage do) You should find an oil draining square nut on the base of the engine (under the mower) a 3/8ths spanner should fit it. Always remove the spark plug lead when fiddling around with the engine, and tip the machine back onto it's handles so that the spark plug is pointing towards the sky. This makes sure that the oil that is in the crankcase doesn't go where you don't want it to! (IE= in the carburettor)
You can now undo the drain plug, and lower the machine back level over you bowl to collect the old oil, when finished, tip the machine back onto it's handles, and replace the drain plug.
Re-fill through the oil filler plug (normally plastic, and found on the crankcase-the other end from the spark plug) with 1 pint of oil (SAE 30) and bobs your uncle. The whole operation should take half an hour (taking into account grazed knuckles, swearing, scraping old grass and mud away from the filler and drain plugs, dropping your spanner into the bowl filled with old oil, and stopping for a cup of tea)
The engines themselves don't require any gear oil, some of the older Mountfields had a crazy drive box that went from the side of the engine to the front axle to drive the mower over the ground, don't worry too much if yopu have one of these, the gearboxes are "sealed for life" and shouldn't need any tinkering.

You should be able to find a manual on the engine. you will need the Model-type, and serial number from the engine, which you should find stamped into the metal of the engine cowling, often above the spark plug, or on the side by the exhaust.
an internet search should get you the information you need.
If I can help further, don't hesitate to call out.

[Honeymonster]

Thanks Gwiz, much appreciated. I'm going to give it a go this weekend, suppose that's the only way to learn! I think half the issue is the machine is so old that the parts number is scratched/obscured so I can't find the right manual and put it this way, i'm not convinced it's got a full service history!?!. I did find the oil fill nut though after wiping away 20 years of grime!

A couple of further questions if I may, would this age/type of engine have some means of checking the oil level? Can I use oil other than SAE30, for example 5w-30?

Again, much appreciated.

Honeymonster

[Gwiz]

I'd always go for SAE30 as it's what is recomended, however, If you don't have anywhere to get some, you could use 20w/50 at a pinch, but remember that it's going to be pretty thin when it gets hot. That means that the engine will tend to smoke a bit (particularly as it is of a certain "vintage")
As for the oil level, for the life of me I can't remember what type of oil filler your machine has, I expect that as you are asking about levels, yours hasn't got the dipstick combined, so it's just a bung with a screw thread on it? if that's the case, the oil level comes to within 5mm of the top of the threads.
A photo of your engine would certainly help to confirm this, as we can't be sure that the engine that is on the machine, is the same engine it left the factory with.......

[Honeymonster]

Thanks Gwiz. Attached should be a photo of the engine. I've had it running this afternoon and it appears sound but operates best on the choke setting. I think it might need warming up quite a bit because even after a few minuites, everytime I slid it back to the Fast-Slow setting in the middle of the throttle the engine began to die. Either that or the carb needs adjusting?

The oil cap is simply that, a cap with no gauge.

Thanks

Honeymonster

[Gwiz]

Good Photo!
The carb is a diaphragm model, the diaphragm being between the carb body and the fuel tank. I would replace this as a matter of course as they tend to become "baggy" and don't pull the fuel up as well as they should.
While the carb is off, you might want to clean out the filters on the bottom of the fuel pick up tube (a common fault being that they get blocked with very fine debris)
There should be only one adjustment screw on this model. wind it in gently until you feel resistance (about 3/4 to 1 1/2 turns) this will tell you what your carb setting is, then wind it all the way out and spray a little carb cleaner down the hole it came from( just as a warning, if you do this with the carb off from the fuel tank, and with the carb upside down in your hand so the bottom is pointing towards your face, you will be in for a nasty suprise- So DON'T!, always have the bottom pointing away from you!!) this will get rid of any tarnish that's built up in the jet housing.
Another common fault with these is that the fuel cap becomes blocked by rust, just make sure yours is ok before pulling anything apart.

[Honeymonster]

Thanks for all the advice you've given me, very useful.

Honeymonster

[Gwiz]

Happy to help.