Briggs 793880 Camshaft failures

[KE4AVB]

Guys, I think I may have discovered what causing all these 793880 camshaft ACRs failures. It is a design flaw in the bump pin. Even when ACR swings out to disable the bump the pin leans out the flat just enough to be constant slammed by the intake lifter (tappet). Therefore it is constant being rocked back and forth flexing the D pin until it fails. Then of course the flyweight goes flying and doing all the damage otherwise to the crankcase internals. Until Briggs redesign this area so the pin is fully retracted even when it leans out we are going to need to keep this camshaft in stock.

Just replace a 793380 yesterday that all was broken was the pin which sent the flyweight into the governor/oil slinger. Even though it took a month to get in three of the new governors, I am already down one.

[38racing]

Possible to grind tappet head to smaller diameter?

[RoyM]

That is like closing the barn door after the horse has bolted unless one wants to tear down every engine in the series regardless of the problem. The new camshaft should take care of it.

[KE4AVB]

I was just trying explain my theory as to why they are breaking and just wishing Briggs would actually redesign the replacement camshafts. I do put in six camshafts this year alone. because of the ACR breakage.

[38racing]

That is like closing the barn door after the horse has bolted unless one wants to tear down every engine in the series regardless of the problem. The new camshaft should take care of it.

I was thinking of only doing that when it's tore down for replacement, if it might prevent another failure on the one being installed.

[RoyM]

Is the problem continuing with the new design? I am retired so out of the loop.

[KE4AVB]

As far as I could tell when I was buying the new PN was they only deleted the tappets and the oil pump drive shaft. I seen no changes to the camshaft itself. I am currently installing aftermarket versions. Two more camshafts to install before I order another OEM 84005207 camshaft.

Besides my distributor sent me email that part orders are being delay due to them being overloaded and overworked on orders so I decide to give them a break by not ordering anything from them until things improve or at least not before 2022. And now another distributor is starting to add a 1.5% surcharge on my orders just because I pay by credit card at the time of the order. They are wanting me to give them my bank account so can withdraw what they want to; not going to happen.

[hanz63]

I'm guessing that if you stay working on these, in ten years they will just go away and you won't see many anymore. Starting with the wonderment of camshaft design, the self oil purge design from the head gaskets they won't fix plus the Wonder-Rama carbs they hang on the side. Though in their defense, who's a wayward valve guide on a newer one this year?

[SUKI]

I'm guessing that if you stay working on these, in ten years they will just go away and you won't see many anymore. Starting with the wonderment of camshaft design, the self oil purge design from the head gaskets they won't fix plus the Wonder-Rama carbs they hang on the side. Though in their defense, who's a wayward valve guide on a newer one this year?

As long as they can get by with it they are going be huge profit off selling replacement parts to repair their poorly designed products. IF they ever was forced to recall all this engines then they would design better engines. It all about how profit they can make off the repairs caused by poor designs.

Besides the OEM is now trying to go to all electric designs.

Personally I got a Bob Cat ZTR schedule to come in with my first EFI engine repair. I just which OEM engine it is. I got the Briggs tester but not the Kawasaki or Kohler testers.

[hanz63]

We'll see. Will it remain full steam ahead after the reorganization?