OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines Briggs Engines and Unleaded Fuel

Hi,
I am fairly new to the Site so still in naive question mode.
I have just purchased a model 45 in very good condition - I want to use it around our newly turfed pool, rather than Victa so clippings are not sprayed into the water and the mowed finish will be better. However I also want to look after this mower.

As it has the Briggs 3hp engine I assume it was made late 70's so would have been designed for leaded fuel. Should I buy fuel additive to prevent the valve stems burning out as one would for a car engine? I have trawled the Forum but can't see this question arising before - that's a bit worrying for the new boy.

I don't want to mess with/dismantle the engine too much but I notice, for example that the is some debris in the fuel tank. The previous owner has given me an Owner's manual for equivalent Rover 45 (downloaded from this site probably) and I have downloaded the engine Operating Instructions from the Briggs site. Is it possible to obtain a Workshop Manual for reasonable money please and also a parts list both for the engine and the mower body.
Regards to all

I'll leave the subject of manuals to Bruce. Leaded fuel car engines did rely on the lead, to some extent to lubricate the valve stems, but more importantly to lubricate the valve seats and prevent valve burning. However mower engines just don't last long enough for this to be an issue. A car engine lasts - before overhaul - 100,000 miles at an average speed of less than 30 mph, or more than 3,000 hours. Relatively few push-mowers last 100 hours. These engines have aluminium bores and aren't a long-life proposition. The lack of lead just isn't a problem.
My solution to the trash in the fuel tank problem is to drain the tank, removing the trash along with the fuel. If any remains, just let the tank dry out and the remaining trash will become loose powder that can be wiped out. I wouldn't disturb the fuel pump diaphragm (between the tank and carburetor) unless it becomes necessary, because you will almost certainly then need a new diaphragm in view of the engine's age.

The whole lead additive thing is a bit hyped up to begin with anyway.

Back when I first got my P's, I bought my vk commodore powered by a trusty old 202, cast iron head, designed for leaded.

At first I ran the old girl on LRP, it was absolute trash, made the spark plugs foul up with a pinkish powdery substance, lacked power, etc.

At around 270000km I just gave up and filled the car with unleaded, I didnt even play with the timing, just drove it as was.

I removed the engine at 309000km to replace it with a fairly modified 6cyl and upon dismantling there was no real amount of wear and tear on the exhaust seats, we reringed the motor and put in new bearings and fitted it to a mates VH commodore, it went well for another year or more before it got written off.

Briggs engines are not really affected by super or unleaded, since the block is cast alloy they have hardened valve seats installed anyway.

Thanks guys for quick replies. At least, just to get started I am now happy that I can change the oil and fill up with fresh unleaded - and give it a whirl. I will take your advice not to separate the fuel tank but will clean as you suggest.

Brian, it is usual practice to run the engine before changing the oil. When the oil has been warmed and stirred-up by running, you shut down the engine and quickly drain the oil. That way you get rid of a lot more of the crud that would otherwise stay on the bottom of the oil sump.

drain some of the oil then add kereosene to the sump. this will remove the gunk pretty well, and wont damage the engine, just dont run it with kerosene in it.

or

drain all the oil then put about a cup of kerosene in the sump, and just pull the starter a few time to let it circulate etc, this will remove most if not all of the remaining gunk.

Thank you again guys, it is great to see interest and support - none of your advice is wasted as I have just purchased an identical machine on Ebay to play with. Just shows how addictive these become. In case anyone was also looking, it was advertised as being left in rain for a month. I couldn't resist it for a winning bid of $82 but my wife is a bit perplexed.

My son-in-law kindly delivered it to me today. Looks ok - a few parts missing, a few parts replaced with later bits I think, so I look forward to hearing from Bruce re workshop manual and parts lists.

Significently it has been resprayed (badly) in places - I read the forum thread about the hammer paint not being available so I will have to have a think about that after I have got it running. If I may, I will come back to the forum with update and no doubt more questions.

Regards

Sorry -forgot to mention, I have looked at the pdf downloads available and the site's 17'' parts list is for model 450423 whereas both my mowers are model 450589. Will that be ok. I also need parts list for the engine, as well as workshop manual. Not asking for much then.

http://cgi.ebay.com.au/Scott-Bonnar...emQQptZAU_Lawnmowers?hash=item1e5b5097b6

I belive this is the one on ebay? Looks good, it dies not look like the engine would be hard to get running again, as for the rest of it, I am out of my depth with reel mowers.

Yes Joe, that's the one. Thank you for the reassurance. I haven't been able to get to it yet as I am still reorganising the shed/workshop. Seems to be a bargain but it doesn't have a catcher of course.
regards

I would be thinking that any American/Japanese small engine built after 1975 should be ULP compatible as this was the year that ULP became mandatory for cars in those countries.

Thank you everyone for your help.

I am having trouble with the second 45 I purchased (my wife is looking smug).I am starting a new thread so the title is appropriate to the content and interested folk will find it easier. I hope that is the right thing to do.

Regards to all

Yes, as you say, it is much easier for people searching this site's archives in future to find your threads if you separate them and give them a relevant heading. Thanks for doing it.