OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Tecumseh / Kirby Engines Kirby-Tecumseh LKV-40 manual?

Would anyone have a manual for the Kirby-Tecumseh LKV-40 engine please?

Hmm, going by the older Kirby-Lauson manual, it would seem that "LKV" is just a fancy way of saying:

L = Lauson, or perhaps "Lightweight"?
K = built by Kirby after 1963
V = Vertical

So I guess this means it is basically equivalent to the American LAV-40?

LAV = "Lightweight Aluminum Vertical"

And possibly it is similar to the earlier Kirby-Lauson VK-40, except that Tecumseh decided to swap the positions of the intake and exhaust valves and ports. I was never sure of the reasoning behind their decision to swap the ports, but I suspect there was some technical rationale for it, when they left most of the other parts the same? It did at times make life difficult for restorers and tinkerers. I even came across a bizarre thread on another forum in which one of their members had tried to swap the ports back to their old positions by altering the camshaft timing. LOL! Of course it didn't work and became more of a technical nightmare than a challenge. He soon dropped the project.

Hi vint-mow
I can only offer my thoughts here.

Tecumseh were the most astute of companies in two strategic moves:
They acquired Lauson 4-stroke designs; and Power Products 2-stroke designs
in the late 1950s.

These would form the basis of future Tecumseh engines.
I have read that Tecumseh chose to retain the Lauson name until the miid-1960s;
because it was an old, recognised name. After that, Tecumseh would remove Lauson designation.

I feel 'L' is more likely 'Lauson'.
After about 1963, we have simple VK designations: VK and HK engines.
These wre the vertical and horizontal Kirbys.
Later on, we would have Kirby Tecumsehs, with the brilliant Indian Chief logo.

https://www.outdoorking-forum.com.au/forum/ubbthreads.php/topics/66618/kirby-brochure-c1970s.html#Post66618

I find it interesting - you comments on the development of this engine.
Maybe the port change was to move the exhaust away from the fuel tank?

Many thanks for your research here.

----------------------------
Jack

Thanks Jack,

Only thing I can add is that according to www.small-engines.com and a number of other American websites, the "L" when used in America indicates "Lightweight".

According to my Kirby-Lauson manual from the 60s, the "LV" together indicates "vertical engine". Oddly, they do not assign any interpretation on the "L", but we presume they must at least be implying it represents the name "Lauson".

According to another source: The LAV35 engine was part of the model series of LV35, which itself may mean L=Lauson, V=vertical shaft engine, and 35=3.5 horsepower. However, in the case of "LAV" it was intended to mean L=lightweight, A=aluminum, V=vertical shaft engine. Both of these engines, regardless of model name, had a 9.05 cubic inch displacement and 3.5 horsepower.

So the Australian VK series, VK-30, for example, indicated a "vertical engine built by Kirby", and in this case rated at 3 horsepower.

G'day vint_mow,
I have a repair manual that covers that model, if you need service specs. Gregory's 'Small Engines Service and Repair Manual' No. 199.

The LKV40 is a bigger engine than the VK40, despite having the same nominal power rating. VK40 is 146cc [2.50" bore / 1.8125" stroke] and the LKV40 is 172cc [2.635" bore / 1.9375" stroke].

Thanks for the info Gadge. I should buy a copy of Gregory's.

I am actually not sure if the engine I have is an LKV40 to be honest. I purchased the engine block "as is" with no idea of the model number. It is actually the same size as the old VK-30 to my eyes, just with valve ports reversed. Everything looks to be the same size otherwise.

So could my engine be an LKV30 or LKV35??? Was there ever such a beast?

I am not sure if there is any way to tell which engine just by looking at it. lol!

G'day vint_mow,
The earlier editions of their 'Small Engines' series manuals cover these Kirby 4-stroke models: LV22, LV30/VK30, VK40, LKV40, HK25. These are Nos 112 [1974, 159pp] and 199, which also cover a few Briggs, Villiers and Victa engines, along with some Kirby 2-strokes.

Note that there are two editions of #199, with publication dates of 1982 [232pp] and 1990 [252pp]. The 1990 version covers the Victa PowerTorque 160cc 2-stroke as well as the earlier 85, 125, 160 and 170cc full crankshaft Victa 2-strokes, hence the greater page count.

These are all out of print, but come up on FleaBay often.

Popping off the head to measure the bore and stroke might be the only definite way of working that out!

[quote=Popping off the head to measure the bore and stroke might be the only definite way of working that out!
[/quote]

Okay I have done that. It has a 2-1/2" bore exactly, meaning it is the right size for a VK-40. I didn't measure the stroke. But I doubt if this is a VK-40 because the exhaust and intake ports are the wrong way around. I wonder if it could be an American engine block, such as a LAV-40? That would explain the reversal of the ports.

Incidentally, the VK-30 bore seems to be 1-1/4", exactly quarter inch less than the VK-40.

Thank you also for the info about the Gregorys books.

G'day vint_mow,

Well, the LV/VK 30 and VK 40 all have the exhaust port at the bottom - not sure about the LKV 40 [haven't been able to find a pic of one]. Is this one opposite? If so, then it's quite possible it's a US model.

The VK 30 bore spec from the manuals I have is 2.3125", or 2-5/16", FWIW.

My mistake, that was a typo. I meant to say my old VK-30 bore measures precisely as 2-1/4". I just went and measured it again and can see you are right. But I would have to say it is just barely 2-5/16". It is actually a smidgen smaller according to my calipers - sort of in between 2-1/4" and 2-5/16".

Just to confuse things, I was just looking at some original LAV-40 engines on a reputable American site that sells Tecumseh engines, and one engine block clearly had the intake port at the bottom, but the other had the intake port at the top. Also they both had different styles of fuel tanks. It seems like there were a number of different models of the LAV-40.

Here is a LAV40-50392E with intake port at bottom.

Here is a LAV40-50386D with intake at the top. http://oldmowerparts.com/LAV40-50386D-Tecumseh-Engine-NEW-P306109.aspx


Photo of LKV-40 attached. (Source: eBay ad).