Thread: Hard Starting B&S Lawnmower

Originally Posted by bee utey

Too true. When I have had the misfortune of working with a BS engine a screwdriver was always at hand to fine tune the beggars. Since the advent of the Honda engine on my mower tuning has been totally unnecessary.

This is a push mower with the carb above the fuel tank.
No adjustment screw on the carb (not that i can find).

Choke is coming off.
New fuel as well.

Originally Posted by crash

This is a push mower with the carb above the fuel tank.
No adjustment screw on the carb (not that i can find).

Choke is coming off.
New fuel as well.

1. I lose track of how many vertical shaft BS engines I've worked on, most were old and cranky and all of those have the carby on the fuel tank, which is why I mentioned carby diaphragms in my first post. Instead of a needle and seat they have a constantly overflowing chamber in the top of the tank, pumped via crank case pulsations.

2. All BS engines I've seen have a mixture screw. From memory they sometimes hide in a hole in the throttle cable bracket.

3. The choke is designed to run with the air cleaner on, perhaps it isn't on properly.

Ended up putting in a 2nd carb kit.
When I installed the first one I some how got the diaphragm missed aligned and one of the screws damaged the diaphragm - I think it was sucking air. After putting the 2nd kit in it is starting easily and running properly.

Geez I am missing out.
My old B&S 375? Rover Craftsman was bought about 20 years ago second hand and it had several years on it then.

I change the oil every few years, and treated it to a new spark plug and air filter a couple of years ago.

It has always started first or second pull and run properly straight away.

I am hoping it will die one of these days as I would like to justify a new Lithium lightweight mower as it is a bugger to lift and push up my hill.

Similarly when I was a kid I did lawns with a Rover B&S and it lasted 15 years and started easily until submerged in the flood of 74 in Brisbane.
Regards Philip A

Originally Posted by PhilipA

Geez I am missing out.
My old B&S 375? Rover Craftsman was bought about 20 years ago second hand and it had several years on it then.

I change the oil every few years, and treated it to a new spark plug and air filter a couple of years ago.


Regards Philip A

I do not change the oil any more - I just keep topping it up!
Growing up I would hate to know how old the lawn mowers were we use to have. Topped up the oil and filled with fuel and then away you would go. I am sure they were B&S too.

I had a one-man lawn mowing business which I sold about four years ago,and I had two self-propelled Rovers on board,20" and 22".Both had Briggs engines which I serviced religiously weekly.The engines were great until they experienced a little compression drop,then if you switched them off when hot you would throw your shoulder out trying to start the bastards.I soon woke up and got my mowershop to fit Honda engines when time came to replace engines or complete mowers.You only needed half a pull to start.Beautiful.They then started to build the Hondas and Rovers in China.They look identical but the quality was gone in both.