Con Rod Install Questions

[JTSpeedDemon]

So I'm almost ready to install the Raptor rod in my flathead, but I have a few questions:
Do I really need a piston ring compressor?
Are the Rotary brand gasket sets Ok?
And which way does the oil dipper point? Is the tapered side towards the front or back?

 

[Kartorbust]

A ring compressor isnt that necessary, however, it'll prevent snapping rings when you drop the piston and rod into the block. They are cheap to buy.

 

[JTSpeedDemon]

Ok.
Also, I assume I need to break in the engine after popping the piston and rod out?

 

[Kartorbust]

I'd follow all instructions that it came with it. I'm not sure if its recommended or not, I'll let someone else chime in on that to give an answer.

 

[Randy H]

Ok.
Also, I assume I need to break in the engine after popping the piston and rod out?

If by break-in you mean run it like you stole it. Then yeah break it in. Lol.

Seriously if your not replacing rings and honing the cylinder, then just run it.

As always my opinions.

 

[JTSpeedDemon]

My rod didn't come with install instructions. Nor do I have the OEM flathead repair manual. Anything I need to know?

 

[itsid]

Sure.. if it's a model 300000 or 320000
the piston will have a notch [1];
and an "F" mark [2] that points towards the valves..

Aand now the important part.. the conrod should have assembly markings[3]
(two nothches that need to align the two parts for correct assembly of the rod )
Those should be inline with the F mark on the piston


what I found works rather well when you cannot find your piston ring compressor
is to use zipties (larger ones.. preferably reusable ones with a release lid)
use them to compress the piston rings.
usually they'll slide off when you tap the piston back in, and if not..
well then you know why a release lid comes in handy at times

'sid

 

[Randy H]

Here's some reading for you.
I've got a couple things you can do to the rod to increase its longevity. If you want to know.

I'd shoot for. 0015-.003. Hope your .002. To tight you can do some journal or rod polishing, teehee. To loose you might think about using the heaviest weight oil recommended.

Keep in mind Plastigauge isn't a precision tool, much like Harbor Freight calipers. An engine builder would use a dial bore gauge and a likely vernier micrometer.
But you got to do the best you can with what you got.

https://www.mymowerparts.com/pdf/Briggs-&-Stratton-Parts-Manuals-IPL/

https://www.mymowerparts.com/pdf/Briggs-&-Stratton-Spec-Charts/

https://www.mymowerparts.com/pdf/Briggs-&-Stratton-Engine-Parts-Manuals-Parts-List/

 

[Randy H]

JT. Here's something you can check, if you want.

With the piston and rod removed, flywheel, sidecover and coil in place. Give the flywheel a spin.

I've seen the bearing /or bushing so worn that when the magnet passed the coil you can see movement in the flywheel.

Hope your good but it's a kind of a big deal if your flywheel is shuckin around.

 

[JTSpeedDemon]

You mean the flywheel side bearing?
I've got a dual flange mounted ball bearing block, but I'll check that for sure.


Come to think of it, when I spin the flywheel on my 3 HP flathead, that flywheel doesn't spin true, it looks like the crankshaft is bent, but it always gets the proper coil gap.
I guess that means the bearing needs replacement?

 

[Randy H]

Yes the flywheel side bearing.

I don't know for sure, but more than a couple thousands of runout would be concerning, to me.

You might secure the engine and carefully pry up on the flywheel. Kind of need a dial indicator but this too will show movement. IDK, maybe try a feeler gauge. If it's real bad you may see it. A leaky seal would be an indicator too. Then again maybe it's just a bad seal.

If the crank is bent, I may have one hanging out. LMK and I'll check.

Hope you can decipher this, haha.

 

[JTSpeedDemon]

Dang, now I really wish I knew the actual code for this engine. Then I could track down parts for it. I need to remove the flywheel anyway to access the ignition points, so I'll check to see if the crank is bent or the bearing is shot. Given that it used to be on a tiller, it was probably just beat up and it's the flywheel side bearing.
BTW - Thanks for all of your input Randy, you're a great help.

---------- Post added at 02:47 PM ---------- Previous post was at 02:45 PM ----------

Also I can't see why the flywheel side of the crank would be bent unless someone dropped it on a ledge with the blower housing off. *shrug*

 

[Randy H]

A lot of times tillers are great finds. They get used a year or two. Then sit for a while, then they don't start. And I pick em up at the scrapyard for .25¢/lb.��

I appreciate the appreciation. Lol.

It brings back memories of tearing these things down with my sons when they much younger. Just a mere 25 years ago. And they remember too.

 

[Hellion]

My rod didn't come with install instructions. Nor do I have the OEM flathead repair manual. Anything I need to know?

Here's the Briggs L-head service manual. I'm surprised you didn't already have it in your oil-stained hands (it's in our FAQ)... https://docs.google.com/file/d/0B6NaqjIxWV1ycG8wd0s3Z2Q2X00/edit

You need the torque specs for the con rod end cap screws. 100 in. lbs. (stock rod) for your application; it's a 5 HP 130000 series. Right?
I imagine the Raptor rod is the same spec.

A piston ring compressor is a great help, especially if you're truly flathead-crazed.
There's some Bubbas out there who can compress the ends of the rings together with a flat-head screwdriver, but that's an easy way to gouge or score the aluminum with the harder screwdriver if it slips.

Assembly lube is helpful but fresh engine oil applied to all the moving parts (especially both ends of the con rod) right before you button it up would be fine.

If you're looking into the engine and the rod is installed, the angled side of the dipper should face the left side of the block. I am fairly certain that if installed in the reverse, the straight edge of the dipper will hit the block as the piston comes up. This will of course help you in orienting the con rod on which way it is supposed to face.

EDIT--put the piston back in the same way it came out. Very important to retain/maintain the same wear pattern.

Helpful video:
https://www.youtube.com/watch?v=3mIgbtznfBY

 

[JTSpeedDemon]

Awesome, thanks man!
Yup, 130000 series.

 

[Randy H]

Eek, looks like I was wrong on the connecting rod install. I sure hope I didn't cause JT any problems. If so LMK and I will make it right.

Very sorry.

Removed some incorrect info from a previous post.

 

[JTSpeedDemon]

Ahh, it's ok. I'd like to get everyone's input, that way I have a better chance at winding up qith the correct info.
Just yesterday I ordered some some green plastiguage through Shamazon.
This is the 3rd time I've used their free Prime trial, and I will continue to do so to get free shipping.

 

[Randy H]

This confirms the video that Hellion posted.

Lesson to me. RTFM.

 

[JTSpeedDemon]

Oh, after looking through the flathead service manual, I realize that I was mixed up carb-wise.
I thought I had a one piece Flo-Jet, but it turns out I have a two piece, as it's determined by if the intake manifold is integrated to the carb or not. So, I have a 2 piece.
Thanks for that manual Hellion! And the video.
I'm gonna wait to install the rod until I can get a piston ring compressor.
If I'm gonna do it at all I'm gonna do it right, that way I don't have to do it again!

 

[JTSpeedDemon]

Ok, I've got everything now, since the green Plastiguage and ring compressor came in, as well as the gasket set.
I also checked flywheel runout, and it spins nice and true(thank to the dual flange mounted ball bearings)
Honestly I would never trade this flathead for any other one with how comparatively exotic and clean this one is.
So now I just need to get over my mental block and git 'r done.
Mostly I'm worried about a sidecover or head bolt breaking, but that's a risk I'll have to take.
I guess I'll have to persuade myself by saying "The longer it waits, the more it corrodes!"
I think I'm actually going to try and do it today.