Thinking of buying a a ____ Quantum? What gives?

[lars11]

The "tall grass cutter" Im thinking of buying is equipped with a ____ Quantum engine. What about this engine? Good? What oil to use after break in? The manual states just SG SAE30 which is almost hard to find, so I assume there may be other alternatives.
I notice that there is a plastic cam shaft, can that be damaged/dissolved if using wrong oil?

 

[Camu Mahubah]

Just use a straight 30w... I have run everything from 10w30 to 15w40 with no problems... I never known a camshaft to dissolve... Right now I am using TropArtic 30w... my mower is a few years old so I just buy whatever 30w is on sell...

 

[Camu Mahubah]

Hold up... I forgot to mention the Briggs did smoke a little when I used 10w30 at startup but stopped after I installed 30w...

 

[Quest]

I got 2 B&S (used to own 4 of them, sold 2 and kept the tiller and the "classic" Quantum mower) and been using 15W40 HDEO oil in it. No smoking whatsoever.

I've also been into doing some sideline work for small engine repairs (mainly B&S and Honda) while Honda is good with 10W30, B&S has been sticking to using mono-vis until recently where they would "permit" the use of 10W30 full synthetic multivis oil in their air-cooled engines.

I don't buy into the so-called "SA" grade motor oil due to splash feed thingy. So long as you change your oil on a regular basis (every 25hrs or so), assuming that the oil you use comes with sufficient detergency to keep carbon in suspension (thus minimising ring-sticking) and enough EP and AW to keep everything running beautifully, IMHO any decent multi-vis motor oil should do fine.

I'm aware of the plastic camshaft on B&S and they are made of nylon, something similar to this one:

http://cgi.ebay.com/BRIGGS-STRATTON-ENGI...1QQcmdZViewItem

Some of the B&S (*esp older ones) are made of metal though:

http://cgi.ebay.com/NEW-Briggs-Stratton-...8QQcmdZViewItem

If this is the case, you'll need to ensure you have sufficient AW and EP additives in your oil to keep it from galling (also consider breaking in the engine just like you would do to your automobile engine).

 

[yeehaw1960]

Quantum engines are a fine example of why Briggs and Stratton are so popular. I'm always glad when a customer brings in something with a Quantum on it to have tuned up. Someone here said before that 10W-30 oil seemed to burn quicker than the straight 30 weight.

 

[Merkava_4]

That plastic camshaft is kinda scaring me away from the Quantum at the moment. I just don't like the idea of that particular vital engine part being made out of plastic.

 

[VaderSS]

I remember an article in Popular Mechanics from the '80s about plastic engine parts. At the time, you'd of thought that, by now, the entire engine would be plastic.

I'd think that if the plastic camshaft was a problem, it would be pretty well known...

 

[tmorris1]

Quote:

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B&S has been sticking to using mono-vis until recently where they would "permit" the use of 10W30 full synthetic multivis oil in their air-cooled engines.

---

I think they actually spec 5W30 synthetic. I am running 5W30 Synpower in my 15 yr old Briggs Quantum. It runs great without any smoking or consumption.

 

[VaderSS]

From their FAQ
Break-In
Oils

Quote:

---

Oil Recommendation

SAE 30 40 °F and higher (5 °C and higher) is good for all purpose use above 40°F, use below 40°F will cause hard starting.
10W-30 0 to 100 °F (-18 to 38 °C) is better for varying temperature conditions. This grade of oil improves cold weather starting, but may increase oil consumption at 80°F(27°C) or higher.
Synthetic 5W-30 -20 to 120 °F (-30 to 40 °C) provides the best protection at all temperatures as well as improved starting with less oil consumption.
5W-30 40 °F and below (5 °C and below) is recommended for winter use, and works best in cold conditions.
Type of oil to use

Use a high quality detergent oil classified "For Service SF, SG, SH, SJ" or higher.
Do not use special additives.
Choose a viscosity according to the table above.

---

 

[Bill Kapaun]

"The manual states just SG SAE30 which is almost hard to find.."

I think if you read closer it will say SG or later"

 

[GMBoy]

I wouldn't worry about that engine's durabilty. I had one (6.5hp I think it was) on an old cheap Murray push mower. I used Mobil 1 in it for 2 years (changed it every season) than gave it to a friend who needed a mower. I purchased a new top line husvarna with a Honda engine and I hate it. LESS power and cheap construction - heck the dipstick tube broke off when checking the oil the first week I had it. Anyway - that old Quantum mower is still going strong and I found out that my friend has NEVER changed the oil in it and its been atleast 2 years that he has had it and he uses it to cut almost an acre once per week. He started it for me and no smoke and ran fine. I told him to change the oil though!

 

[psudaytona]

I am running VP Racing Synthetic Ester 10w40 in our new TroyBilt 4 cycle weedchacker. It seems to like the stuff.
Its a tad hard to find SAE 30 around here as well. Just some cheaper old Castrol on the WM shelf.

The crankcase only holds 3 oz, so its not alot to change it often. And the engine is so smooth

 

[yeehaw1960]

How do you like the 4-stroke weedwhacker? I worked on one twice (a Ryobi). The engine about twisted it out of my arms, but it broke the lower drive cable twice.

 

[psudaytona]

I actually like it alot. The engine is very strong but there isnt much in the way of vibration. Only thing I don't like is the odd angle that the trigger is at, it makes my hand cramp and fall asleep(go totally numb).

This one was just purchased to replace a brand new Ryobi that 20 hours into operation suffered a sudden massive failure, engine totally siezed and welded its piston to the cylinder wall!

It is very quiet when it idles and you can clearly hear the valves on it!

It reminds me of the small engines I hear on newer Saturns and Hondas really.

It was 169.99 from Lowes, a good buy I think.

 

[tom slick]

briggs engines have had nylon cams for about 20-30 years. don't worry about its "new technology", they are very reliable.

 

[Dr_No]

My ol lawnmower lasted 15 years without failure.
Tore it down and the camshafts were plastic, still in good condition.

 

[jsharp]

The valve spring pressures are so low and the RPM is so limited in these small OPE engines, I can't imagine plastic internal parts being a problem. Provided they're designed properly and kept lubricated anyway...

 

[lars11]

ok, then quantum it is. thanks all.

 

[Dr_No]

http://www.briggsandstratton.com/display/router.asp?docid=98712

There are your features, nice choice!

 

[jsharp]

I don't get what's so special about those engines. They appear to be the same 50 year old Briggs design with a better carb and fancier plastic. Still a flathead, still splash lube, etc. I guess they do have a cast iron sleeve. I suppose that's an improvement over the low end models...