Briggs raptor flywheel strength

[Liberty_Jesus]

How does the raptor 3 flywheel hold up at 4500- 6000 rpm much closer to 4500 rpm but 6000 rpm is the max for safety leeway. Will it blow apart like a standard one on a standard 5hp Briggs flathead? Is it a standard 5hp flathead flywheel? I'm assuming I'll need a ARC flywheel for safety. I still have to open up the raptor and make sure it's all ok but how will the flywheel hold up at that rpm? Will it hold? Oh and I saw in another post that the stock raptor 3 rod is good to 7000 rpm is this true?

 

[Budget GoKart]

Considering its a raptor itll be fine

 

[Liberty_Jesus]

Considering its a raptor itll be fine

Hmm probably I mean the Dyno chart I got for a raptor 3 says they pushed it to 6500rpm
Here's the PDF with the Dyno numbers
https://www.google.com/url?sa=t&sou...Vaw1DleaWJ5as8qp4ai_jBxiJ&cshid=1583928852759

 

[itsid]

the stock raptor flywheel is cast!

and since that's a pre owned engine (and a cheap one at that),
you cannot be sure.. originally that flywheel was good for quite a serious amount of rpms..

one idiot unmounting it with a hammer or dropping it from the workbench is enough to make
it UNSAFE even at 4000 rpms.

So, take it slow at first and allow the confidence to raise over days and days as you go.
if you're lucky it'll announce a fatal failure by vibrations and you can stop before if fails.

don't floor it on day one I'd say.. an unknown engine can pack quite a nasty surprise if mistreated by the PO.


'sid

 

[Liberty_Jesus]

don't floor it on day one I'd say.. an unknown engine can pack quite a nasty surprise if mistreated by the PO.

I'll make sure not to floor it I'll limit my throttle usage on the first day.

 

[JTSpeedDemon]

An ARC flywheel would be a sensible upgrade. Plus it improves the rev up time.
Although, with stock flywheels, Briggs have a history of being better than Honda clones, as the air blades are one piece, and the magnets are retained much better.

 

[Liberty_Jesus]

An ARC flywheel would be a sensible upgrade. Plus it improves the rev up time.
Although, with stock flywheels, Briggs have a history of being better than Honda clones, as the air blades are one piece, and the magnets are retained much better.

alright i still wont push it as much until i get a arc flywheel which i am saving for.

 

[JTSpeedDemon]

 

[KartFab]

the briggs 5 hp flathead flywheels are built using better caster materials, and use horizontal pins for their magnets vs the glued on vertical screw clone magnets.

I would run a tecumseh or briggs stock flywheel to 7500 rpm with no worries.

The primary sources of failures in clone engines are from extremely poor quality control /bad castings, but most failures in these engines are when the magnet flies off of the flywheel as it is only held on by a single screw and some glue. Briggs and tecumseh dont have these quality conrol or magnet issues.

A billet flywheel would be on order if i were going to have an all out build, but a stock/hot stock build would not need a billet flywheel in my opinion.

 

[Liberty_Jesus]

Alright but should I still properly pull the flywheel and inspect it? I'll have to pick up a puller but I think if I'm running it at a max of 6000 rpm I should insure there are no cracks.

 

[itsid]

the problem is there isn't much you can do..

you can pull the flywheel and inspect it visually..
maybe try a ring test
hung from a string and tapped with a screwdriver handle it should ring..
a dull sound can be an indication of a hairline
(your mom knows the dull sound it'd be very similar to dinner plates with hidden cracks )

the problem is the only truely reliable thing to do is x-ray inspection..
and neither of us has such equipment I guess
So not seeing or hearing anything doesn't necessarily mean you'd be good to go.

On the other hand if you do see or hear something, you'll be better off not even mounting it back again but instead wait for the funds to grow for the arc flywheel instead.

'sid

PS there was some "inspection fluid" around.. essentially UV-coloured penetrating oil...
sprayed onto the part to inspects and then wiped off it stuck in all those hairlines you can't see with the naked eye and revealed them under UV light .. can't remember what it was called though

 

[Liberty_Jesus]

Alright I'll probably just run it if there's any heavy vibration I'll take it off.

 

[jmaack]

look up liquid penetrant test. this can be done from basically anyone's home supplies. it wont be the best but it can help with cracks. kerosene or diesel and some talc powder.

 

[Liberty_Jesus]

Alright sounds good if I can get a flywheel puller I'll do that