OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines Briggs and Stratton 171 cc oil issue

Hello everyone,

I came across your site via a Google search on "Rover Super Four 21"

I have a Rover Super Four 21 self propelled mower that I just got from a friend. I *think* it would possibly be from the 70's ?
He has used it previously without issue but has only owned it for about 2 years and not much use.

The issue I have is I can mow for about 50 meters or so and the motor would stop. I do have some mechanical ability, so did the basic trouble shooting - fuel - no issue, air - no issue, spark no issue, so I started it and watched it.
After a few minutes I saw it has some type of low oil cut off that seems to come in to play and moves a metal rod that cuts the motor, so I presumed that it must be low on oil.

So I unscrewed the oil cap and saw that it doesn't have a dipstick on it so I am unsure of whether it does actually need oil or how much. Regardless I put some more in to what I presume must be the level (where it runs in to the hole....I hope that makes sense). However it still cuts out after a few minutes.

Any ideas ? Apart from having to pour a little fuel in the carby to get it to start as it has no primer, it runs very well. I couldn't find a manual for the mower online.

Also I was wondering whether parts are still available for them, the two rollers that press on to the wheels are very worn and need replacing and the drive belt also looks to be on its last legs. I don't mind spending a little on it as it is in quite good condition.

Thanks for any help,
Austech

(edit - Bah, I just noticed that I didn't see the model type and code on the motor, Model = 100902 Type 0222-03 Code 75112006.......I will do some more Googling and no doubt find out more )

Welcome here Austec,
I pretty sure any coil off any of the smaller Briggs motors will fit and the later ones have a built in module so you don't need the points and condensor so that removes 2 other possible causes. Millions of those flathead Briggs lying around everywhere.

The low oil cutoff you refer to is the governor. The reason your mower stops is almost certainly fuel related. Try adjusting the mixture settings but i think a new diaphragm and a rebuild would be required.

Usually to see if it's a spark or fuel problem you can run the motor with the air cleaner removed and when it starts to cut out put
a little fuel down the carby if it still cuts out you know it's a spark issue ,a bad spark plug will run then get warm and cut out and
so will a bad coil .

The drive dogs that run against the rear wheels haven't been available new for many years ,you can replace them with
second hand ones if you can find any that are in better condition or make some or weld them and grind them back to
original specs.

Last time I converted one of these briggs to electronic ignition was decades ago and from memory I used a coil from a Quantum
but I still had to grind the end of the metal core to match the curve on the flywheel.

Cheers
Max.

Thanks for the replies.

For no particular reason it is back to up and running. Interesting to know that is a governor !

I mowed the lawn with it today and must say it runs well, it cut great and it looks a million dollars. You wouldn't know I used no catcher, nothing to be seen.

If anyone has any idea where I can drive dogs, please let me know. These are gone and the back wheels are bald so there is basically no traction.

Cheers
Andrew