Intek 40 Series Pushrod Length vs Adjustment Range

[Dave_C]

Lawn mower has a B&S Intek V-twin 19HP
Model 407777
Type 0137 E1
Code 980422YG

Does anyone know what the spec is for the pushrod length?

It overheated, valve guide slipped, bent one or more pushrods. I got the pushrod part #s, 690981 (steel, exhaust), and 690982 (aluminum, intake).

I was sent a generic kit labeled CT160 (or CTM160, something like that), which is supposed to be the above two part #s but compared to a bent steel exhaust rod that was pulled, the new pushrods look about 1.5mm shorter.

I checked the engine service manual # 273521 and it doesn't spec the pushrod length.

Is there an acceptable range of length that can be adjusted for, is something 1.5mm shorter likely to work okay? I'd just throw it in and try to adjust it but the mower is at my mother's place and I'd like to have viable parts when I get there.

 

[Craftsman Garage]

Pretty sure that when you adjust the valves, it will compensate for it being shorter

 

[Dave_C]

Yes I know there is some adjustment as I'd adjusted it previously when it burped trying to start it (a few years ago, I did not cause this, lol), but I don't know, if after a couple+ decades of wear (maybe around 600 hrs), if 1.5mm shorter is outside a reasonable expectation of adjustment range.

 

[Tiger Small Engine]

Yes I know there is some adjustment as I'd adjusted it previously when it burped trying to start it (a few years ago, I did not cause this, lol), but I don't know, if after a couple+ decades of wear (maybe around 600 hrs), if 1.5mm shorter is outside a reasonable expectation of adjustment range.

Are you changing the cylinder that overheated and pushed the valve guide? Did you thoroughly clean the top of engine and cooling fins from debris after it overheated? This mower is 25 years old and has been around the block a time or two.

 

[StarTech]

The old 690981 which supersedes to 597785 is 6.275" (159.385 mm) in length per my caliper.

 

[Dave_C]

The old 690981 which supersedes to 597785 is 6.275" (159.385 mm) in length per my caliper.

Thanks! I was just reminded that my caliper is only 6", so I had to extrapolate, after beating the old bent pushrod close to straight.

That gives me old pushrod length 159.25mm, two new steel 157.75mm, and oddly the two aluminum are different lengths from each other, about 157.25mm and 158.25mm... gotta luv quality control!

 

[Dave_C]

Are you changing the cylinder that overheated and pushed the valve guide? Did you thoroughly clean the top of engine and cooling fins from debris after it overheated? This mower is 25 years old and has been around the block a time or two.

Changing the cylinder? You mean a new head? I was hoping to just replace the pushrods, dremel a groove on the valve guide while it's sticking out, that would end up just below the level of the head, put some high-temp red loctite on, pound the guide back down and stake it in.

Yes there was a lot of grass muck built up and that has already been cleaned off. I also considered pulling the head, then tapping it and using a set screw as I've seen Taryl and others do on youtube videos, but still trying to decide.