Briggs & Stratton 35 classic (mountfield self propelled)?

I tilted my mower to the side and oil leaked out. Now when I run it, blue smoke emits from the engine. How can I stop this? Also what type of oil is required for topping up because now the oil is low?

Roberts
June 2015

I tilted my mower to the side and oil leaked out. Now when I run it, blue smoke emits from the engine. How can I stop this? Also what type of oil is required for topping up because now the oil is low?

Roberts
June 2015

I tilted my mower to the side and oil leaked out. Now when I run it, blue smoke emits from the engine. How can I stop this? Also what type of oil is required for topping up because now the oil is low?

Roberts
June 2015

is it easy to remove and fit a new diaphram to my classic 35 mower.would this solve the running rich problem thanks john

john
September 2013

i repair mowers and machinery in the neath area and its a very common prob we normally change the gasket and diaphram as a kit replace air filter and clean carb it works every time , what is not realised is that the diaphram is a wafer thin piece of rubber and it deforms over time its a cheap and easy fix normally costing 10 pounds ontop of a service im on 07891563455 if anyone needs advice

steve
October 2012

Update on previous post. My scepticism was well founded after all and the confident diagnosis froM Celtic mowers was incorrect. After replacing the fuel, the mower ran well for a while, but the chugging and black smoke returned.
I decided to go with other posts and replace the diaphragm. The good news is that you only need to buy the diaphragm replacement kit and not the full S2 kit. Get part number 795083 from Briggsbits.co.uk for £5.87 including shipping. The other good news is that it's easy to change. See an excellent video on YouTube - http://www.youtube.com/watch?v=C5nzigcNTwo&sns=em
There are two gaskets - a normal sealing gasket and a thin rubber one which are both sandwiched between the carburettor and the fuel tank. Just two bolts release the carburettor and and fuel tank as a unit, making the rest easy. The only fiddley bit is releasing the throttle linkage (but not difficult). Also watch that the rubber sealing ring and it's retaining clip may come off onto the intake manifold (as it did with me). Easy to pop it back into the carburettor before rebuilding.Clean as you progress with lots of carb cleaner.
On inspecting the old rubber diaphragm, the problem seems to be that a small round area with a spring behind it functions as a crude pump and this part had become stretched.
All back together and working well. Spark plug still clean after a prolonged run.
I think I've finally cracked it!

Ospreylian
August 2012

I had this exact same problem - engine chugging and black exhaust smoke. Cleaned the air filter - no change. I was about to order a gasket as mentioned below, but first managed to have a chat with a lawn mower repair specialist (Celtic Mowers in Swansea - very helpful) who recognised the problem immediately. They suggested it was oil in the fuel. I was sceptical - wouldn't that cause blue smoke?
Anyway, worth a try. Siphoned out the remaining fuel and ran the engine until it ran dry as instructed. New fuel in and wow! It's now running perfectly.
Worth a try - it didn't cost anything!

Ospreylian
August 2012

I have a mountfield mower from B&Q with a briggs & stratton engine in it, It starts up ok then starts chugging putting out black smoke, engine running arraticaly then stalls.
I take out the spark plug & it's realy black so i clean it up & the cycle starts again.
It will only run for about 2 minutes between cleening the plug each time.
I've cleaned the air filter & changed the oil, does anyone know what could be causing this.

Dave.36
June 2012

Mine just idles, no acceleration, starts OK but will not rev up, any help!!

Sonny
March 2012

All these type B&S motors with the same fuel pump gasket are prone to the same problem.
They run with chuffs of black smoke out the exhaust and the other symptom is surging from idle to full power constantly.

Replace the gasket and you'll be sweet.

Jason
November 2010

my 35 classic chug chugs along then cuts out,please help.

paul
October 2010

http://www.mowerfix.info/Problem_Solving_Guides/B&S%20CLASSIC%20SPRINT%20400%20SERIES%20SELFHELP%20GUIDE%202009%20Issue%202,0.pdf

A link to the service manual.


Jim

Jim
August 2010

where is the dipstick and how do i drain the oil?

niall
September 2008

can any one please send a photo of a 35 stratton classic of where the two springs go ie idle spring and the governer spring on carbretto as both mine have somehow dissappeard and iam not sure where they go? jonny7410@aol.com thanks

john
August 2008

i find a little bit of urine with the 2 or 4 stroke oil works a wonder...

... no... seriously, i saw it in a forum like this one, and was a bit skeptical at first, but thought 'hey' might aswell try it, and it worked ;)

green man
August 2008

i had a similar problem with my briggs and stratton 35 classic. it seemed like the engine was stuck on full choke- chugging, with a lot of smoke and little power. the first thing i did was change the air filter, which was filthy & helped a little. when i took it to the repair shop the guy told me the only problem this engine ever has is the fuel pump gasket - 2 pieces of rubber that go between the fuel tank and the primer assembley.heres a link for the Briggs and Stratton Carburetor Service Kit S2 for around £15 - http://www.briggsbits.co.uk/acatalog/copy_of_Quantum.html

luke towley
July 2008

Same engine same problem - I'm looking for an online service manual: no luck.

Salisian
June 2008