Intek 40 Series Pushrod Length vs Adjustment Range

[Tiger Small Engine]

As a professional shop I don't do this to my customers. I warranty my workmanship and if the repair don't hold it bites me in the anus.

Beside grinding on the cast iron valve guide will weaken it. Another option I have heard of is to pull the head drive the guide back in place and spot weld the guide inside the valve chamber as these guides are usually pushed out. Even that I don't recommend. But it is the OP's engine and he can take the risks if he wants to as he can always repair it again if it fails again or replace it. Just note there is no replacement guides.

BTW any beating on the valve guide usually means it will need reaming to correct size.

I don’t do this repair this way either for a customer. It is a new cylinder head, clean top of engine of debris, etc.

 

[Dave_C]

Just out of curiosity are these from Briggs or are they after market?
Also note the 796632 and 796633 cylinder heads have been superseded a few times. They even at one time came as a set for half the price but quickly changed that back to individual heads out of China. Current heads are 84001918 (#1) and 84001919 (#2) and they are not a stock item from Briggs direct. IE slow boat from China.

The pushrods were aftermarket. I noticed the new part #'s, supposedly improved with a lip so the valve guide can't slip up. I looked around and they seem to be going for about $190 and up, each. If my repair attempts don't work, and don't result in trashing the engine internally, then I'll end up getting the 84001918 as it is cylinder #1 with the slipped valve guide. Cylinder #2 looked to be okay still.

 

[Dave_C]

If you cut a groove in valve guide, insert a c-clip into the groove so it stays put. Make sure it is at correct depth of course. You can red Loctite it and peen it also.

There seems to be some difference of opinion where these valve guides are supposed to sit. Some state that they only stick up out of the rocker arm side of the head by 1/8" or so, and have some area sticking out the other end, which might be enough clearance for a c-clip, but other people state that the back of the valve guide is supposed to be flush with the head and stick out a bit further than 1/8", which seems more consistent with pics I've seen of new heads.

If I'm taking the head off anyway, I plan to tap a hole and put in one or more set screws. For now I am considering trying just the loctite threadocker and staking it, seeing if that holds up long enough to get the fall leaves mowed up as there are a ton of them accumulating while the mower is down. I suppose someone could be hired to mow a time or two to get rid of the leaves but they're not even close to done falling yet. In this climate the grass is no longer growing till around late March.

 

[Dave_C]

As a professional shop I don't do this to my customers. I warranty my workmanship and if the repair don't hold it bites me in the anus.

Beside grinding on the cast iron valve guide will weaken it. Another option I have heard of is to pull the head drive the guide back in place and spot weld the guide inside the valve chamber as these guides are usually pushed out. Even that I don't recommend. But it is the OP's engine and he can take the risks if he wants to as he can always repair it again if it fails again or replace it. Just note there is no replacement guides.

BTW any beating on the valve guide usually means it will need reaming to correct size.

Okay but as a shop, what would you charge to put the new head on, and presumably clean it out since it is likely brought in with nothing done yet? I figure that's at least a $450 service with parts, right? The mower isn't worth more than that, is a (roughly) circa 1999 Scotts aka Murray, which works fine besides the engine but isn't long term investment worthy. A new head at $190-ish is about the limit. If the other head also needed replaced, it would blow the budget to replace them both.

Grinding on the cast iron valve guide? I'd just put a groove in it for peening around that, to have some purchase on it, or a dimple for a set screw. It looks steel (shiny silver), doesn't look like it would be easy to weaken it. If loctite and staking it, then a set screw doesn't keep it still, I may find some welder to do that. I think the main issue with a set screw will be whether the loctite threadlocker stays set up at the head temperature. It's rated for 450F but since this is a side load, might not slip without it doing its job.

I found yet another alternative which is a machined washer that sits over the casting, under the spring. Here's a video example:

 

[Craftsman Garage]

Well, you get what you pay for. If you want your engine to actually run good, do yourself a favor and get Briggs Oem.

 

[slomo]

Moral of this story is CLEAN YOUR COOLING FINS. Swear this has been posted on here buy one of us.

 

[Dave_C]

Moral of this story is CLEAN YOUR COOLING FINS. Swear this has been posted on here buy one of us.

Yeah the problem in this case was that I'd always used a leaf blower all over the mower, which gave the false impression that nothing was building up anywhere since I couldn't see the buildup on the heads.

 

[StarTech]

And Mice, Mud Dabbers, and Jenny Wrens are quick to build nests. And mice loves chewing wires and hoses too.

What a lot of people don't understand when trying to stay cheap is how much it costs to have someone else mow their lawns. I had a couple to complain about my repair estimates until they checked out having someone else to mow their lawns. They quickly had me to repair their old mowers. And last year I had one customer that thought $750 was too much to repair a JD mower that they were abusing but was willing to spend $3500 on a new mower because they could get it on credit.

 

[Tiger Small Engine]

Okay but as a shop, what would you charge to put the new head on, and presumably clean it out since it is likely brought in with nothing done yet? I figure that's at least a $450 service with parts, right? The mower isn't worth more than that, is a (roughly) circa 1999 Scotts aka Murray, which works fine besides the engine but isn't long term investment worthy. A new head at $190-ish is about the limit. If the other head also needed replaced, it would blow the budget to replace them both.

Grinding on the cast iron valve guide? I'd just put a groove in it for peening around that, to have some purchase on it, or a dimple for a set screw. It looks steel (shiny silver), doesn't look like it would be easy to weaken it. If loctite and staking it, then a set screw doesn't keep it still, I may find some welder to do that. I think the main issue with a set screw will be whether the loctite threadlocker stays set up at the head temperature. It's rated for 450F but since this is a side load, might not slip without it doing its job.

I found yet another alternative which is a machined washer that sits over the casting, under the spring. Here's a video example:

Technically, by the service manual, the mower shroud is supposed to be removed once a year and the engine and cooling fins checked for debris, to avoid overheating.

Paying $450-$550 to remove and replace a cylinder head, head gasket, decarbon, and set valves, etc. on a mower that is worth $450-$550 is a judgment call. A new bottom of the line basic riding mower is $2000. Mower probably needs a tune up also and there are sometimes other small issues. The cost keeps rising. One thing I will say is that going through all that work and “just seeing if it can get through the end of the season “ seems rather short sided. Cut a groove, Loctite it, put in a set screw, and peen it. Throw the kitchen sink at it.

 

[slomo]

Technically, by the service manual, the mower shroud is supposed to be removed once a year and the engine and cooling fins checked for debris, to avoid overheating.

So true so true. On every air cooled engine out there.

More often if bagging or scalping. Some riding baggers can dump grass up high and get sucked into the shroud. And when you empty said bags it pours out all over the engine.