Rebuilding a blown up Briggs Quantum Engine [Part 2]

[@paulesposito5939]

Great video. Referred to it multiple times as I had to replace the connecting rod on my B&S Quantum lawn mower.

[@CraigArndt]

I may have missed it, but I'm assuming you wet sanded the crank. At least to take the high spots off. I've found when cranks let go, it's not just the scoring of the journal and rod bearing or cap, but sometimes the heat can cause the journal to go from round to egg shaped. That of course would make a knocking sound. Nice video, you guys are learning lots and having fun and that's what it's all about.

[@vernonbosshard9317]

Correct on marking the tappets, they need to be installed on the same lobe. Besides the valve clearance may change too.

[@sisyphusuphill5213]

Excellent video showing us in a very modest but very knowledgeable manner how it can be done. Thank you!

[@geraldolmstead1335]

There is no way sandpaper will correct the problem with that crank.I'll be surprised if that engine runs 1 or 2 hours before it starts knocking. Just being candid.-Jake Olmstead

[@tmackinator]

Nice vid. There is an old method for polishing crank or rod journals involving wet dry sandpaper and a wide shoelace. You wrap the lace around the paper on the journal and use the lace to spin the paper back and forth. Change grits as you go to achieve the best finish. It works amazingly well without removing excess material. Search the web for a better description of the procedure but its worth knowing.-TM

[@daphantom1173]

No amount of polishing will true that crankpin. The slighest deviation or irregularity on the crankpin journal will cut out the aluminium conrod, big end bearing surface, in very little time.

[@lestergillis8171]

Make sure your wrist pin retaining rings are inserted at the 12o'clock or 6o'clock position. NOT 3 or 9 o'clock.

[@akio2589]

What most likely happened is it still have break in oil from the factory that no one ever changed. That would explain the weird smell and premature failure. That oil isn't meant to lubricate for long.

[@TomTom-by5sx]

I'm wondering if they ran 10W oil to clean out the inside and ran it to long?

[@vernonbosshard9317]

You can use some hydrochloric acid to remove the residue from the crank, it will eat off the aluminium fast but will not eat the steel fast enough to harm it. I think you use 50/50 water and acid. Then you polish it. Also you didn't mention which way the piston was installed, it can go on two ways but only one correct way.

[@davetracey4063]

Whats up Vernonski?

[@radoczi94]

Just a thing: if you heat up the piston and cool down the pin in the fridge, the pin will just fall in the piston easily.

[@midgyrich]

That makes sense

[@BAZZAROU812]

This seems to be a issue.. I've seen several broken rods on these..

[@paddibaek]

Hi i got the same problem on my engine so where did you buy the connecting rod 😃

[@43128lucky4]

that looks like it may have came out a pressure washer because it has an onboard throttle and choke, if it was off a mower it would have had a cable

[@darrellhidalgo9436]

Where can I get that very first part you took off the engine

[@Venturi2012]

Well some small engine parts stores will carry it, or look online. I believe the technical name for it is a wrist pin retainer.

[@condega123]

Where did you buy the parts from?

[@dinohudson1432]

Prep the cylinder? (Honing)

[@funnypranker34]

I'll tell you something. If the engine has a adjustable throttle you don't need the governor because by increasing rpm, you get increased power output. But don't rev it so high that is self destructs. I say under 5000 rpm is good for a stock motor

[@Venturi2012]

In this case you need both. As you use the power washer, you go in between 0% load on the engine, to a pretty high load as you cycle the wand. If using a non-governed throttle, you could set it at 5,000 rpms at free revving, but as you pressed the wand handle, the load would drop the rpm's way down to nearly an idle speed. The governor compensates greatly for this change in load, making it automatic in a way. The rpm's still drop slightly as it cannot compensate 100% due to the general concept of a spring and governor system.

[@funnypranker34]

Forgot about that one Venturi2012. But the governor like you said compensates or the load but also reduce engine rpm reducing power. If the engine was for example used on a motorized vehicle like a go kart, you won't need a governor because the only engine load is the weight of vehicle being moved. But on that setup, if the engine bogs a bit at start, the engine will make that up quickly.

[@vernonbosshard9317]

+Peter Kapica Not true, when the engine is under load they need more fuel.

[@funnypranker34]

Im not talking about fuel, im talkin about the governor

[@mowerrepairshopfortscottkansas]

Some Flywheels don't come off like that

[@DIYOneForAll]

Why are these connecting rods made from soft aluminum?

[@scrappysgarage7404]

I'll give you one word: "cheap"

[@acidking202]

Hmmm.... No carbon on the piston top, really clean inside, and oil smells of rubbing alcohol????? I would guess someone ran too much seafoam thru the carb throat, and revved it to death when it started to stall. That rod has been shattered by a Hydrolock.

[@akio2589]

Nah, probably break-in oil from the factory that no one ever changed.

[@JayjayWalkers]

That's the crankcase not the combustion chamber

[@RottenCash]

where do you get the gaskets for these engines?

[@Venturi2012]

I'm sure they're available from online stores, but I got all the parts I needed from a local small engine sales/service center

[@carlingcarling8146]

thanks for sharing ur awesome

[@douglasmorrison9098]

I KNOW U DIDNT USE THAT CRANKSHAFT BACK BAD NEWS IF YU DID

[@midgyrich]

3:05 Lol that, or it didn't have any oil to burn!!!

[@cliftt]

That HF torque wrench is as good as a craftsman. Check videos comparing them to snap-on etc.

[@360S0DJefferson]

I'd be interesting in finding out if those plastic parts like the cam cost the same as the steel cams of previous generations of Briggs engines. Talk about planned obsolescence. Not impressed and won't be buying one of those.

[@pickle1990able]

Nice job u know your shit

[@charlesblack265]

motor should been torn all the way a part

[@carlingcarling8146]

I'm doing my lawnmower right now

[@performancecyclespecialtie6104]

Beginner mechanic

[@dntlss]

Although a old video You did read in the description that they got the engine from a high school related program? at least they are building a engine and not gangbanging.

[@charlesblack265]

motor should been torn all the way a part