Tecumseh with worn valve guides

[creia]

1970 Tecumseh HS40 - 55282B
I know that the valve guides are worn. I would like to know how much by taking measurements of the stems OD and the guides ID and comparing the clearance measurement with factory specs. Can someone provide me with those specs please? That is to say how much clearance is too much on this engine (i.e.,"reject size")?
Thank you
Michael

[StarTech]

If they are worn you ream out for a 1/32" oversize valve.

Hint> They OEM STD are 1/4" valve stems so use Briggs 1/4 Valve guide replacement reamer 9/32. I haven't seen any Tecumseh engines so it is a guess but I think can possibly use the Briggs replacement valve guides and then use STD valves but as I said I haven't seen a Tecumseh engine. They were way before my time.

[Arkie]

1970 Tecumseh HS40 - 55282B
I know that the valve guides are worn. I would like to know how much by taking measurements of the stems OD and the guides ID and comparing the clearance measurement with factory specs. Can someone provide me with those specs please? That is to say how much clearance is too much on this engine (i.e.,"reject size")?
Thank you
Michael

Might be more info than you need, but:
You can get some Tecumseh spec info on this site if you will go to the Technical Service info section.
Look under Tecumseh and your engine is probably the Horiz shaft, 4 hp, L head. (valves in block=flat head or L head)
Download the 3-11hp flathead service manual that bobodu posted and look in the rear (about pg 80 something for all kinds of engine specs.
I think the Tecumseh valve guides at permanently installed in the block and if they are worn may have to be reamed 1/32 Over and new valves. This oversizing the guides is mentioned in the Tecumseh L-head service manual download, I think. New parts are getting hard to find for Tecumsehs. You might try m&D mower for few Tecumseh parts.
You might nose around Lysle , thexton, etc and maybe find a valve guide knurler, but not sure about this.

[creia]

Thank you both for your replies- very much appreciated. I do already have the Tecumseh L-Head Manual and have read the information that you have provided. While I know that I do have WORN valve guides, I am not so sure that they are WORN OUT and need replacement. No where in any Tecumseh manual or other literature can I find any specifications ("reject size" if you will) as to what measurements constitutes replacement. If anybody knows, I welcome that information. In the absence of specific Tecumseh specs, is there a generally accepted industry standard for these small engines as to what is the allowable clearance for a valve stem in a valve guide?
Thank you,
Michael

[38racing]

I assume that tecumseh didn't have a plug gauge like briggs. Don't know if 19381 is the briggs one but if you needed it which of these would you order.
https://www.repairclinic.com/PartDetail ... mber=19381
or
http://www.mowtownusa.com/Briggs-Stratt ... 21547.html

[38racing]

the manual says' valve guide oversize dim' and 2 numbers .2807 and .2817 . So is that a range and over .2817 means to oversize them? Or is that what the oversize range should be? Meaning the original range would be 1/32 less ie .24945 to .25045? Would that mean you could get a rod turned to .25045 and if it's a nogo you are ok?
update: looking at the reamer its says the oversize dim is the .2807 to .2817 .

[StarTech]

Why not just order the Briggs 19269 1/4" valve guide repair tool kit? The valve guide Go/No Go tool is 19122 and the reamer is 19064 (9/6432). It a heck of a lot cheaper than ordering the two individual tools. The reamer alone is over $30 and the kit is around $55 which includes a reamer guide cone. The reamer in the kit also has a pilot tip and most others don't if like the ones from Atlas or Fastenal. If I had to do over again I would still just get the tool set.

38racing, the valve guide gauge tool you listed is for the Briggs Models 20, 21, 31, 33, Vanguard™ engine Models 104700, 161400, 260700, 261700 and single cylinder OHV Model 280000. It is for .2354 in. (5.98 mm) valve stems and not for the 1/4 in valve stems which are .245 in. (6.23 mm).

[38racing]

Why not just order the Briggs 19269 1/4" valve guide repair tool kit? The valve guide Go/No Go tool is 19122 and the reamer is 19064 (9/6432). It a heck of a lot cheaper than ordering the two individual tools. The reamer alone is over $30 and the kit is around $55 which includes a reamer guide cone. The reamer in the kit also has a pilot tip and most others don't if like the ones from Atlas or Fastenal. If I had to do over again I would still just get the tool set.

38racing, the valve guide gauge tool you listed is for the Briggs Models 20, 21, 31, 33, Vanguard™ engine Models 104700, 161400, 260700, 261700 and single cylinder OHV Model 280000. It is for .2354 in. (5.98 mm) valve stems and not for the 1/4 in valve stems which are .245 in. (6.23 mm).

I had just picked a plug gauge from a briggs tool list and looked it up. My point was the crazy price difference between two suppliers. Is the conclusion right that tecumseh says ream +1/32 and use oversize valve and Briggs says ream 1/32and use a 1/32 thick guide.

[StarTech]

I had just picked a plug gauge from a briggs tool list and looked it up. My point was the crazy price difference between two suppliers.

Actually it is an error on the part of Repair Clinic as they have the guide PN 19381 superseded to a Snapper wheel cover PN 7019381SM.That is something I should send an email off to them about.

Is the conclusion right that tecumseh says ream +1/32 and use oversize valve and Briggs says ream 1/32and use a 1/32 thick guide.

Correct though guide as actually slightly larger for a tight fit. This was something AVB and I had problems with a few years ago as an aftermarket guide we were using was even a larger OD wise. Finally ended up buying a reamer that of the correct size (19/64). Those AM guides are nla now anyways so that is mute point. Personally I liked the AM guides they were less likely to collapse when being driven in. Now the question is "Are Tecumseh engines able to have the Briggs guide installed?". This is something I don't know as I have never did one of them. I haven't even a Tecumseh engine in my shop and I would thought I would have.

Now those Briggs replacement guide once driven in is finalized at .250 inch by using a 1/4 in (.250 in) finish reamer.

[creia]

I do very much appreciate the additional replies and the continued discussion on my topic- Thank you all very much!
With that being said, I find it hard to believe that there is (apparently?) not a published wear limit measurement/standard so that I can simply measure my valve stems OD and subtract it from the valve guides ID and compare my engine's clearance to the "worn out" clearance standard. Just like you do for determining if a cylinder bore is worn out.
Michael