Small Engines (Lawn Mowers, etc.): Bent Push Rods, engine rebuilder, old briggs

Question
QUESTION: Sir: I have a 5 year old Briggs 24hp Intek V-Twin. Starting last season, have bent both aluminum and steel push rods on one cylinder, several times. Properly gapped them late last Fall and it ran fine up to winter storage. Turned it over yesterday and it popped and began to run on one. Same problem. Both left cylinder rods bent and valves remained shut. Bought spares last Fall and replaced, gapped and pushed valve stems to make sure were loose. Reassembled and it started and ran fine. I'm putting "Sea Foam" in crankcase and gas to help if valves are sticking. Can't figure any other reason for bends. I'm afraid it will happen again. Any ideas what's causing this? Thx. J - Webster, NY

ANSWER: Let me guess this is on either a simplicity or an MTD right?   

This has been an intermittent problem.  your going about it the right way not only repairing the problem but repairing the root cause.

You need to run a valve reamer through the guides to enlarge them a bit.  What is happening I have been told is the push rod is expanding with heat which stops it momentarily and bends it.  by the time you get the engine disassembeled the push rod is no longer seized in the guide.  Does this make sense?  
So the fix is a larger valve guide or just make it a lil bit bigger with a reamer.  Any engine rebuilder in your area should be able to help you out.

Refresh my memory where is Webster NY   I used to live near Albany... (Clifton Park)


---------- FOLLOW-UP ----------

QUESTION: China Dave: Thanks for the reply. Mower is a Sears but one of their more expensive ones, made in USA by same Co. that makes Bolen and Huskvarna. Webster is eastern suburb of Rochester, bordering Lake Ontario. I'm a little confused re. the valve guides. On the push rod side of the rocker, the rods fit into the head with a lot of space already (width). Also, it appears that they bent on start-up after working in late fall. Engine was cold at start-up. They must have bent on the first "pop". I'm suspecting that problem is on the valve side of the rocker, but the valves are always free when I take it apart, ie. I can depress the stem and springs. Also, If I was to ream out the guides (are they the rod channels?), what would I use? Thanks again. Even if I have to take it in which I will if this happens again, I'd like to be able to advise the repair people what to look for. John

Answer
John,

give the folks in technical services a call at Atlantic Power.  

https://www.atlanticpowerinc.com/web/contact/

They are the Briggs distributor in your area, not only will they be able to help you with your problem, but can help guide you to a dealer in your area if you need service help.

The guides are generally replaced or reamed with a reamer.  Most engine rebuilding facilities have these tools.

The folks at Atlantic power are good people and will get you on the right track.  

I don't know all the information, but i can always guide you in the right direction.