Connecting Rod 101

[Billy Goat]

Iam in the middle of repairing a Briggs and Stratton 5 HP Quantum Engine. The connecting rod broke and Iam replacing it. When I got the replacement connecting rod, there were two other parts in the box. After doing some research, I would say the one part is called a oil slinger (Dipper) and the other is called a lock plate? This engine has a combo governor/oil slinger so I believe I dont need to install the slinger to the connecting rod. My question is about the lock plate? What is it and what is it use for? I found no other evidence of any other broken part in the engine except for the connecting rod. The engine parts break down doesnt show any such part. I researched and internet and found no information or photos with the lock plate installed. I only found photos like the one I attached to this post.

Attached Images

	ConnectingRod.jpg (4.4 KB, 10 views)
	BreakDown.jpg (34.0 KB, 9 views)

[stevef1201]

Lawn care business tips

have yo tried fitting the lock plate over the connecting rod where the two bolts go? Is it possible that it 'locks' the two bolts so they wont come unscrew? I have seen things similar, the corners of the plate are bent around the bolt heads so it cannot back out during operation/ just my thoughts-not an expert

[Billy Goat]

Originally Posted by stevef1201

have yo tried fitting the lock plate over the connecting rod where the two bolts go? Is it possible that it 'locks' the two bolts so they wont come unscrew? I have seen things similar, the corners of the plate are bent around the bolt heads so it cannot back out during operation/

The corners on the lock plate are flat. Plus the bolts have a round edge on them. Photo attached. I would hate to put or not put this lock plate on and find out otherwise if the engine fails because of it.

I want to make an educated guess and say it helps supports the connecting rod from breaking but I could be wrong. I searched and viewed hundreds of photos on the internet and not found one thing about this so-called lock plate.

[RoughCut]

I'm not a expert also, but have repaired too many motors. Most parts fit many different brands. So BS might not use a locking plate. If the old connecting rod didn't have it,don't use it. That being said if you can't tell if the old one had one, then I would throw the engine away, because could be block damage. Also use new connecting rod bolts as the new ones have locking threads or sealent on them. Usually come with new rods
Hope this helps.

[bruces]

pretty sure your talking about the little sheet metal piece in the first picture you attached ,and that goes in between the rod bolts and the cap and the ends are bent once installed to keep the bolts from spinning out .

[Billy Goat]

Sometimes little things can be a big headache. I was trying to get the 2 bolts off the new connecting rod and one of the hex heads stripped (rounded) out. Not sure if was because the bolt was torqued to tight or the bolt was simply cheap. I was not in the mood to try to remove the bolt in fear of damaging the connecting rod. I figured it was easier just to buy another connecting rod. This time I found a orginal service part made from briggs and stratton instead of the other brand (Stens). I was happy because in the box had instructions on how to install the rod along with installing the lock plate. Even had the bolt torque specification.

These instructions do not state anything about bending the corners of the lock plate around the bolt heads. From what I read it acts like a washer. I will try to scan and post the instructions if anyone needs them.

[Steve]

Yes please do. I would love to see the way they explain it and what you were able to do.

[wandfsmall]

Originally Posted by Billy Goat

Sometimes little things can be a big headache. I was trying to get the 2 bolts off the new connecting rod and one of the hex heads stripped (rounded) out. Not sure if was because the bolt was torqued to tight or the bolt was simply cheap. I was not in the mood to try to remove the bolt in fear of damaging the connecting rod. I figured it was easier just to buy another connecting rod. This time I found a orginal service part made from briggs and stratton instead of the other brand (Stens). I was happy because in the box had instructions on how to install the rod along with installing the lock plate. Even had the bolt torque specification.

These instructions do not state anything about bending the corners of the lock plate around the bolt heads. From what I read it acts like a washer. I will try to scan and post the instructions if anyone needs them.

As a dealer I know the likely answer to this question but was the OEM part much higher then the aftermarket lower quality part?

[Billy Goat]

Originally Posted by wandfsmall

As a dealer I know the likely answer to this question but was the OEM part much higher then the aftermarket lower quality part?

In this case, I purchased the OEM part from ebay for $10 delivered. The aftermarket part was $15 delivered. The crankcase gasket was $5 delivered. 95% percent of the time I can find what Iam looking for on either eBay or Craigslist. Iam a one man army so I have to be jack of all trades, master of none.

I service all my own equipment. I dont make enough profit yet to purchase commercial equipment so I try to buy the best used residential equipment I can find. I only do small lawns with my own equipment. Iam surprized how good some of the equipment holds up not being commercial grade. I been impressed with Briggs & Stratton engines for the past few years.

I dont do snow removal so I the time to service my own equipment durning the winter months. Generally, you can find good prices on equipment and parts if you have the time to search the internet. Also I watch alot of repair it yourself videos on youtube.

[Billy Goat]

The operation was a success. Reassembled the engine, added oil and gas and she fired up after a few pulls. I ran the engine for about 45 mins at idle speed to break in the new connecting rod. Tomorrow I will I bring the engine up to full power and see how she holds up.