Intek 40 Series Pushrod Length vs Adjustment Range

[TobyU]

Where can you get small quantities of metals at a delivered price that is cheaper than a couple of pushrods? If the ones I have don't work because there isn't enough adjustment in the rocker arm screws, I can just order the genuine B&S pushrods, or see if a local John Deere or whoever dealer might happen to have some in stock.

This is what I first thought of and recommended in my first post, I didn't read all of the entries..
You should be able to order from eBay or Amazon and if they say the brand name is Briggs & Stratton and they show a picture of the package then hopefully it will be a brand name OEM when it comes in.
Unfortunately some things are bad online about this as they do it with belts too.
I will not put an aftermarket belt on a machine because they never last as long and half the time they don't even fit right or work right whether it be not engaging properly or disengaging.
It simply isn't worth it for the few extra dollars you save.

I say the same about push rods.

 

[kbowley]

While all these suggestions are interesting, they are not the correct way to fix it and prevent issues down the road. God lord, man, just buy the correct OEM parts and fix it right.

 

[Dave_C]

While all these suggestions are interesting, they are not the correct way to fix it and prevent issues down the road. God lord, man, just buy the correct OEM parts and fix it right.

I can appreciate your position on this, when a customer is paying more for labor than parts, and you want to minimize come-backs, but I am very much about replacing/refurbishing down at the discrete component level of what actually failed and reusing the rest, whether it be a furnace, car, washing machine, computer power supply, whatever.

Often that saves equipment down-time and repair time too, but in this case I trade a little time for the learning experience, and the valve guide might just pop right back out, I accept that, but it was a pretty tight fit going back in, plus the additional measures taken, so I have hopes.

Plus it saves me money, creates less waste in landfills and from mining/manufacturing/distribution of goods that "may" not need replaced, though at this point, if it ends up needing a new head, it'll get one.

 

[kbowley]

I can appreciate your position on this, when a customer is paying more for labor than parts, and you want to minimize come-backs, but I am very much about replacing/refurbishing down at the discrete component level of what actually failed and reusing the rest, whether it be a furnace, car, washing machine, computer power supply, whatever.

Often that saves equipment down-time and repair time too, but in this case I trade a little time for the learning experience, and the valve guide might just pop right back out, I accept that, but it was a pretty tight fit going back in, plus the additional measures taken, so I have hopes.

Plus it saves me money, creates less waste in landfills and from mining/manufacturing/distribution of goods that "may" not need replaced, though at this point, if it ends up needing a new head, it'll get one.

I respect your position, and in my 45 years of doing this, I have driven many valve guides back in as well as peened in many fallen-out valve seats. Sometimes they last forever, other times one mow. My respectful point is that you are not paying for labor, and the head replacement is much easier than your current path, and it will be fixed right. Going through the hassle of having to remove the head once again if it fails is a PITA. However, if it doesn't overheat again, it may be fine.

 

[Dave_C]

So when you guys pull a head on the B&S Intek V-Twins, do you take off the intake manifold too?

I tried to skip that step, just unbolted cyl #1 head from the intake and left the intake in place. I got it off fine that way, but putting it back on, was a challenge... might've been because I had a generic gasket kit and the intake gasket was thicker than stock, but I could not get the head on the guide pins, seated down on the cylinder, nor even off it a little, and coax the intake gasket into place.

What I ended up having to do is torque the head bolt that sits inside the valve cover, most of the way to get enough clearance, then loosen it a little and wiggle around the head quite a bit while pushing on the intake gasket with a screwdriver to nudge it over, then once that was bolted on, loosened back up the head bolt I'd put in and then put in and torqued the rest of the head bolts in the right sequenced stages. I was surprised that this part of the repair would be where it took longer than anticipated.

Those shorter pushrods, there was barely enough adjustment available on the rocker arm screws to accommodate them, but there was and got most of it back together, had to replace a fuel line that didn't like being bent after ~25 yrs, started it up and it seemed to run good, but I didn't run it for long nor mow with all the covers and front end off the mower.

Not sure if I have a head gasket leak, or an exhaust gasket leak (I'd reused the exhaust manifold gaskets because they had been taken out of this gasket kit previously), or if with the shroud off and the mower not moving, I'm just not accustomed to where the exhaust would go as it looked like a little smoke coming from an unusual location on (or near) the repaired cylinder, but it was hard to tell for sure, and wasn't running rough at all.

I stopped at a couple auto parts stores to get a loaner compression tester or leak down tester but both were out of them. Might call around to check for one at a few more stores, or just break down and buy one on Amazon.

This topic has exceeded it's original purpose which was to figure out whether generic aftermarket, shorter pushrods would work. The answer to that is, yes in my case with the amount of wear my engine has, yes, 1.5mm shorter will barely work. Would I buy the generics again instead of OEM B&S pushrods? No.

 

[Dave_C]

I ran the engine for a few minutes and checked the rocker arm to valve stem clearances again, after having set them to 0.005" previously, and the clearance grew so they were adjusted to 0.005" again. Rest of mower was put back together but it's been raining every day and lawn staying wet, so didn't get the chance to try to mulch-mow up the leaves yet.

 

[Auto Doc's]

Teryl fixes all has some good ideas, but he also has the tools and experience to modify components as needed.

I recommend you get a used head and lap in the valves and replace the valve seals. Also take the time to resurface the head using a section of flat tempered glass and some 400-grit sandpaper.

Make sure all cooling fins are cleaned out well and keep them clean. Pressed in valve guides move due to severe overheating and poor oil maintenance.

The 1.5mm length difference is an allowable difference that can be adjusted out.

 

[Dave_C]

^ I considered a used head but then thought, what is stopping anyone from taking a head that had this problem, cleaning it up and (only) tapping the valve guide back in, and then selling it? I'd be no better off than I started.

If ALL the heads with the new part #, are the redesigned ones with the lip to keep the valve guides from moving, then I'd have more assurance, but for now, I'll see how long my *fixed* head holds up. The mower is 100% put back together and just waiting for the lawn to dry out before mowing again.

 

[Dave_C]

Just wanted to update the topic.

There were abnormally high winds here that blew the leaves away, so didn't end up needing to mulch mow them last fall, so didn't use the mower again until today.

Mowed for an hour and so far the repair described previously is holding up, though I'm sure the head will get hotter in the middle of summer, but so far, so good.

I did do a (cold engine) compression test on both cylinders to see how they looked and was surprised to see that even with this B&S having that compression release-whatever feature to aid in starting, both cylinders were around 170PSI. It's a crappy cheap compression tester so possibly it is inaccurate, but I was under the impression that the compression numbers would have been lower than that, even with an engine in good shape. I did do the valve lash adjustment again on both cylinders, so it's not that. Possibly my valve adjustment wasn't perfect, but it's not burping when trying to start it like it was back when I had to do that adjustment the first time.

Regardless I was happy to see that the cylinder for the head I'd worked on, was close to the PSI for the other one, even has slightly higher compression than the one I hadn't touched (due to lapping the valves, I'd assume). I don't recall if I mentioned all the details but I had a concern about whether my lazy attempt to not take the intake manifold off, had prevented enough clearance to get the head to seal well against the head gasket, but apparently it's sealing fine, even with the generic $10 all-gaskets kit I got off ebay a few years back, which as I mentioned previously, had a little oversized cylinder bore hole like it was also meant for the next size up displacement B&S engine.

Now that I've written all that, it will probably grenade itself, but fingers crossed...
It's a 26 year old consumer grade mower so I'm not hoping for it to last another 26, just a while longer.

 

[TobyU]

While all these suggestions are interesting, they are not the correct way to fix it and prevent issues down the road. God lord, man, just buy the correct OEM parts and fix it right.

Spending all that money for a Briggs & Stratton OEM head that puts you right back to where you started from with a head that is -barely adequate to do the job is not what I call the correct way. Lol
It may be an okay way and it could even be correct by briggs standards or others but it certainly is not the best way.
A machinist or someone who had worked in a machine shop with automotive engine heads would laugh at one of these but they would also know exactly how to prevent future problems but good luck getting any of those people to screw around and waste time with a lawn mower head.

So forgive me if I don't have much confidence in a brand new OEM head being one bit better than the original one that's already failed and especially not being bulletproof.

Now, to be accurate, most of these don't fail unless there is nesting or severe buildup causing them to overheat but still, the design and the safety margin is terrible.
So my point is since you're supposed to clean off all the nesting and the cooling fins when you have the shroud off and the engine apart, you could take any head that is a good head and bolt it on and get the same results you would from a brand new one.