OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Tecumseh / Kirby Engines Kirby Engine - from the 1970's

Hi
I am new to the forum. Very proud SB cylinder owner - passed on to me by my grandfather

Sadly the oringial kirby engine is on its last legs - i know i cant get parts, but now having trouble with either getting too much fuel through, or not enough. Runs beautifully when it is going, but then just stops running and wont start again very easily.

any ideas - or is it not worth the hassle and does the kirby finally need replacing?

Cheers
Brad

Could you pop up some photo's of the engine and particularly the carby, it sounds like a repairable issue to me, we just need a little more detail on which engine you are running.

There should be a plate on the engine somewhere with numbers on it, those numbers will also help

Thanks Ty - Will try to get some photos up later tonight or tomorrow

I think Kirby H4 or something similar to that.

Loathed to spend big $$ if a new engine is the better option, but to my non-mechanical brain sound fuel line/flow type of issue???

There is a standard process to follow through what you have described. First, disconnect the fuel line at the carburetor end, put a cup or something under it, turn on the fuel and check the flow rate. It should be full stream, not a trickle. If that is OK, you will need to check the carburetor's float pivot and needle and seat. Begin by reconnecting the fuel line to the carburetor, then remove the float bowl and check the rate of fuel flow - it should run out from the seat, past the needle, and down into your cup. It should be a flow, not a series of fast drips. Then gently lift the float and see if the flow slows and stops. Remember, be very, very gentle. If the fuel flow starts and stops smoothly and consistently when you move the float up and down, you will need to remove the carburetor and clean it, then check the float for leaks (and probably fuel inside it). Next, carefully inspect the float pivot pin and the pivot arm, checking for smooth operation.

Your carburetor is 40 years old, and may have some wear, or accumulated grunge in the wrong places. There is also a good chance the float is leaking fuel to its inside. None of these issues is likely to be serious, you just need to get it all cleaned up, and any float leaks soldered up.

Your old HK engine is in some ways not the most lovable one in the world, but it is mechanically very durable. There is no call to scrap it over a dirty or sticky carburetor.

Thanks Grumpy - will go home tonight and follow your intructions. Will let you know in the next few days. Sounds easy to follow and perhaps fix, and certainly save me a few hundred dollars getting a new one.

It is an oldy but a goody - this is the first problem that i can recall and i have had it 10years or so, and i have had plenty of offers to buy it each time the blades are set and sharpened!

Brad, to many of us, old mowers are best when they retain the original specification. It can be enjoyable to use a mower that is a collectors' piece as well as a good mower - especially when on top of that, it is a family heirloom.

Your Kirby-Lauson may eventually wear to a point where it needs a major overhaul, perhaps using another old HK as a donor for parts. If that happens you may elect to put a relatively modern engine on it for everyday use, and repair the original one for eventual re-fitting when you finally retire the mower from ordinary use. Whatever your plan, it is bound to be worth tidying up the original engine and keeping it, in good running order, either fitted to the mower or packed and stored.

thanks for your suggestions

here are the pics that i took. Hopefully it will give you a better idea. I do wish to keep using the current engine- has worked so well till now.

It did have some sludge in the carby, which i have since cleaned, but the fuel tank has some residual coffee like granules from some old fuel firmly attached to the fuel tank walls. Does anyone know of replacement equivalents that might fit?

Model is H4-4a. interestingly, last night when i started it there was fuel squirting out of a needle size hole on the top left hand side of the carby. Could this be a result of too much fuel? Float and arm seemed to move freely...

I will have a closer look later but I really do not like that govenor spring (the bright silver one) The tecumseh carb is a somewhat troublesome beast but it can be rectified.

The little hole in the top flange of the carburetor is usually there to let fuel squirt out if the float bowl floods, to keep the surplus fuel from running out of the main jet into the intake pipe and harming the engine. So, it sounds as if your carburetor is now flooding due to grunge between the needle and seat, or perhaps a stuck float arm but that is less likely.

You reported major fouling of the fuel tank. Most likely some of that has now moved downstream into your carburetor's fuel intake area, upstream of the needle and seat. You need to clean out the fuel tank, the fuel hose, and the fuel intake fitting of the carburetor.

If the interior of the fuel tank is not substantially rusted, it should be easy to remove the deposits from the inside. The gum (fuel residue) can be removed with a solvent such as carburetor cleaner. Nodules firmly attached to the inside of the tank can be removed by putting hard objects into the tank and shaking it until the crud has been bludgeoned loose. Then you tip out the hard objects and most of the loose nodules, and rinse out the rest. Always get the fuel tank properly clean before you bother to clean the carburetor, because all that happens otherwise is more crud from the tank just undoes your good work.

From what you've said your old engine has the usual collection of crud extending through its fuel system. Clean the tank, then the fuel hose, then the fuel intake into the carburetor, then if necessary the rest of the carburetor (main jet and drilled passages). When you have the tank and hose clean, you will have to remove the carburetor from the engine to do the rest of the cleaning chores. I suggest you begin your preparation for cleaning it by reading this set of instructions:

http://forums2.gardenweb.com/forums/load/lmower/msg061726346162.html

Remember, your engine is actually an old Lauson engine. Lauson was bought by Tecumseh, and the early Lauson engine was then licensed to James N. Kirby in Australia, for local production. Yours is an Australian-made Lauson.

Please come back to us when you have the tank and hose clean, and you have read the overhaul instructions. We can talk about any issues you have with the procedures involved. I recommend that you do not dismantle any more of the carburetor than necessary, because you will damage parts that may be difficult to replace. Read all the detail, but do not proceed with it at this stage. All we will want to do at first, is clean out the area upstream of the float chamber's needle and seat.

thanks for all your help

On the way home from work i called in to the local mower stores and found a number of whole kirby engines, that had been put in the 'spare' racks. Anyways took the best engine and now have good working parts that have now been placed on the old machine - bingo!! also have a box full of spares including governor springs etc

Doesn't like full throttle though, seems to get choked up with excess fuel. Might take the carby off and replace it with the new one altogether, when i get time, but certainly now working much better.

thanks again for all your suggestions
one very happy SB owner

From your description of what is happening now that the governor is working, it sounds as if your choke may not be opening completely, or the air filter may be fouled up and restricting air supply to the engine. You should check that the choke is opening fully by inspection (remove the air filter and look at what happens when you move the control - the choke should open wide, so you are looking at the butterfly edge-on). While the air filter is off, inspect it and give its foam element a wash in clean petrol, then wet it with engine oil and wring it out.

The easy way to check for carburetor problems is simply to temporarily switch the questionable one for a known good one, and see what effect that has. If the problem moves with the carburetor, then the original carburetor is the source of the fault. Then you fix it, by following a manual.

I agree with Joe, that nickel plated spring doesn't look anything like the Lauson governor springs I have seen. If you made a major improvement by switching it for a standard Lauson spring, that is a step forward.

Now that you have parts that work, you should be able to sort things out quite easily.