briggs 5hp flathead help

J

joshmckinley78

New Member
#1
#1
some one stripped out the threads on a flat head crank i picked up. the threads the starter screws on to.

so my question is are all 5hp flat head cranks the same size can i pull one out another 5hp flathead briggs and just swap them or what size thread is it so i can try to re thread the crank . thanks for the help
 
sparkwizard

sparkwizard

#4
#4
From my recent and limited experience, there are at least two different diameters for the round dowel sticking out past the threads. I installed a crank from a newer engine and my older starter ratchet was too small to fit. HOWEVER, I was able to cut that shaft off and use the nut, starter cup and recoil assembly from another engine. So, in my experience, the threads are the same. If your engine has ball bearings on either end, the replacement needs to be the same.
 
Harquebus

Harquebus

Well-Known Member
#5
#5
The crankshafts are not all identical or interchangeable. You need a crankshaft that matches your specific engine. There's two basic types, regardless if it is supported by (one or two) ball bearings or plain bearings only:

1. The old style crank has an extension that the old style starter clutch rides on (the all metal starter clutch/ratchet with the balls inside).
2. The new(er) style crank lacks this extension and uses a cup starter on the crank/flywheel. The starter mechanism in the blower cover is totally different and uses plastic pawls that deploy to engage notches formed on the inside of the steel cup, and this in turn turns the engine over.

The bearing style has to match too, or you may install a ball bearing crank inside a plain bearing block, which won't work.

Please post the engine code numbers inscribed on your blower cover. The number for a 5 HP usually starts with 130XXX. Hopefully it is the original blower cover, sometimes they are not. With those numbers, one can find an illustrated parts list that will depict which crankshaft and/or part number is correct for the engine.

Post good photos of your current crankshaft too so the forum can determine if the threads can be restored or if it is a lost cause.
 
Harquebus

Harquebus

Well-Known Member
#7
#7
Superb. That post should be pinned for easy retrieval.

Page 41 Fig 9 names the crankshaft extension as "clutch pilot" that the later crankshafts don't have. The clutch pilot is used together with the Briggs and Stratton 399671 Starter Clutch just to reiterate.

Good stuff.
 
Harquebus

Harquebus

Well-Known Member
#9
#9
joshmckinley78 said:
130232 mode in 1987
Click to expand...
That's not all the numbers. I want the whole set.

130232 only tells us:
13 = displacement in cubic inches
0 = basic design series (not sure what that means)
2 = horizontal shaft, pulsa-jet carburetor, pneumatic or mechanical governor
3 = ball bearing, flange mounting, splash lube
2 = rewind starter

It says you have at least one ball bearing on the crank, but you probably knew that.

I decoded that with the help of this site, which everyone should bookmark:
Briggs and Stratton Numerical Number System
 
Harquebus

Harquebus

Well-Known Member
#11
#11
Yes, there will be a larger seal for the ball bearing in the crankcase cover...and a bigger seal on the flywheel side too.

Your engine with an exploded parts diagram and the parts list is at the link. If you want to replace the crankshaft you're going to have to take it apart and only then will you be able to confirm what you have...especially with all those variations that DeathStarJanitor posted.

You can have different variations within engine versions, depending on the engine application. The engine code doesn't seem to denote what kind of crankshaft it has or can have.

https://www.propartsdirect.net/brig...r,GearCase,Piston_Grp/130232154101/8090002ABI

Crankshaft is number 16, part #: 493290
 
sparkwizard

sparkwizard

#12
#12
Does your engine have a starter clutch that is screwed onto the crankshaft, or is there a steel nut threaded onto the crank, with a steel cup held on, similar to a washer?
 
creia

creia

#14
#14
https://www.ebay.com/itm/175918164513
I don't see any scoring, however, when buying a used crank you take the chance (and risk) that the crank pin or either of the journals could be worn out of spec. When I have purchased them I always ask the seller to provide precise measurements- some will and some will not.
Michael
 
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Harquebus

Harquebus

Well-Known Member
#17
#17
sparkwizard said:
...it's really tough to strip a steel crankshaft with an aluminum nut. Is the nut stripped and the crank threads are clogged up with aluminum?
Click to expand...
I might be mistaken, but I think the Briggs 399671 Starter Clutch IS cast aluminum but the threaded portion is a steel insert. They may have made some of them all aluminum though. Figure Briggs knew this was a part that would be removed often for servicing the starter clutch itself and the points ignition behind the flywheel so they made sure it wouldn't gall on the crank extension (or be a vector for galvanic corrosion between the two dissimilar metals).


HEY OP we still want to see pics of your crankshaft. :scooter:
 
Harquebus

Harquebus

Well-Known Member
#19
#19
joshmckinley78 said:
bad pics but will get better
Click to expand...
You weren't kidding, those are tiny photos. Please take off the blower shroud and get better pics of the crank threads. That rust on the shaft needs to be removed (with a wire wheel on a Dremel or angle grinder, cordless drill or do it by hand with coarse steel wool or 500 grit sandpaper, etc).

Looks like your engine has a Raptor style blower shroud that eliminates the rewind starter. On those, they start them with a hand held electric starter like the Burris MiniLite or Coleman brands.
 
markus

markus

Well-Known Member
#20
#20
Hey Nate the scammer, I mean Josh ;) maybe you should check this engine out on FB to get parts from….if anything you would have a perfect matching set, even the corrision spot on the flywheel cover is dead match to yours IMG_4548.png
 
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