I don't know what it is about this engine, but I have found no less than 10 broken intake push rods all in different engines. The intake is aluminum, and the exhaust is steel. I have switched the aluminum to steel with no apparent problems. I contacted Briggs and they said that it saves 14 cents per pushrod by using aluminum. Man. What ever became of "quality"
B & S intek 10 1/2 HP intake push rod
- Thread starter chance123
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My Intek digested and ate a steel pushrod. It was in two pieces in the sump. I believe it was processed through several bites of the timing gears. I don't know who cheapens these tractors. It's probably the system designers prodded by "the market," just like the auto industry. For instance I rave on about overheat which could be reduced with a ? $50 oil cooler, guage, and owner manual warnings. But that fix is probably another dirty little secret . IMO
Lawnranger
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I had the same thing happen with an engine under warranty and Briggs blamed it on bad gasoline. I asked how bad gasoline could cause a broken push rod and they responded by saying that the bad gasoline varnished between the valve stem and guide which caused excessive force to move and the push rod was the proverbial "weak link". Next time I get a Briggs engine with a broken aluminum push rod I will do the same as you and use a steel push rod.
My original thought as to why Briggs used a steel push rod on the exhaust valve was to handle the extra heat but they denied it and didn't have an explanation as to why they use steel on the exhaust and aluminum on the intake. My second thought was that if both push rods were steel and something in the valve train locked up, the aluminum push rod would break saving the engine from more damage. Your thoughts?
In the automotive industry, if you save ten or twenty cents on every vehicle produced by using less expensive material or even eliminating an inexpensive part you would save the company millions of dollars and as a result one of the exec's could hire his brother-in-law as another V.P. Of course this is my opinion only but I don't doubt it happens.
OK , I'm started again...I stated earlier on this forum some reasons I found for valve train problems on the Intek. Indeed, other forums have stated that one failure mode of hung and then bent pushrod is "coke" or deposits in and around the valve guides. One culprit iis shutting down an overheated engine. This forms deposits on the valve guides which can inhibit proper actuation. The cam says "lift," the pushrod says "I can.t." Bend and drop out . Don't know how a bent, intact pushrold can worm or fly through the oil drain hole in the head. These are the ones found lying waiting topside for the owner to replace them and adjust valves. Only to again fall out. This coke problem tortured auto turbo charger bearings until water cooling or cool down instructions came along. A lawn mower owner cannot possibly know his engine is overheated without a guage. I doubt even the best 92+ octane gas with its superior additive package can prevent this.
My failure was also ( IMO ) overheat , but the pushrod somehow launched through the small oil return passage into the sump to be paratially digested. I also had a loose valve guide due to overhead. There were no coke deposits. :2cents:
My failure was also ( IMO ) overheat , but the pushrod somehow launched through the small oil return passage into the sump to be paratially digested. I also had a loose valve guide due to overhead. There were no coke deposits. :2cents: