The intake valve is the lower of the two, should have the aluminum push rod- set to .003". The exhaust to .005". Before making the adjustment, check the rocker studs at the head (bottom) w/ a 10 mm wrench and make sure they are tight. The adjustment is done cold, 1/4" either past TDC or 1/4" back before once TDC is reached. TDC is where the piston reaches the top once the intake valve closes.

So the intake pushrod is aluminum? Weird. My intake pushrod is steel. Why did they make the 2 different metals?

Need to follow the exhaust port path to know which Is intake and exhaust. If in fact the al. is on the exhaust side then somebody has tampered with it and put it together wrong. IMO same reason the make compression release, so they can make component parts cheaper. With compression release don't take no heavy duty starter system to crank if over. Light weight equate to Cheaper manufacturing costs and design IMO Intake don't get as hot or stress at exhaust so parts can be made cheaper IMO of course.

" 1/4" either past TDC or 1/4" back before once TDC is reached."

???

Note that when properly installed, ALL B&S Engine use an aluminum push rod on the valve which is utilized for Compression release. In the case of B&S V twin Vanguard engines, the aluminum push rod is on the EXHAUST valve.

18.5 Intek would be on the Intake.

I can send you a Service Manual for your engine IF you like, address below, put in propber format and remind me, engine model number and what you want. I am having commuter trouble so don't be surprised at delayed reply.

Walt Conner
wconner5 at frontier dot com

I think I read somewhere that you should rotate the pushrods around each valve adjustment to avoid uneven wear-is this correct?

Switching the aluminum push rod end for end will prolong its' life IF the engine is one of the older ones which has a fibre guide that the push rod rides on. Newer design does not have this guide so no need there.

Walt Conner

I have a 18.5 briggs that is hard starting and back fires out the exhaust when trying to start. I took the valve cover off and the exhaust valve had a tone of lash in it but there was no cap like the intake valve is one needed on the exhaust side ? Any other suggestions on the hard starting and back firing would be greatly appreciated

Yes. It has the same cap. Look for it. It is magnetic should you have a small magnet on a stick. Was the rocker loose on that side? Look closely at how far the valve guide protrudes from the head. Without the seal on the intake valve, they would protrude about the same. The valves too should be sticking out both the same, either with the rockers removed or where you set the valve lash at- 1/4" past TDC after the intake closes. If the head checks out and you get the valve train reassembled / lash set you should be good to go.

Got further in it and it ended up being the exhaust valve seat was out and wasnt letting the valve close completely .. thanks for the help