Jacobsen Lawn Queen

[Austen]

I've been having so much trouble with my Jacobsen lawn queen that I think I'm going to put one of my spare engines on it. For some reason when I put the mower to an idle for a little bit and then gave it full throttle it won't rev up again for some reason. I've spent a lot of time working on it and rebuilding and adjusting the carburator on it that I think I am going to put one of my spare engines for it on there. I was wondering if it was possible to convert a rope start to the Jacobsen recoil with the four starter balls? I'd like it to be original and have the recoil instaid of the rope start on the spare engine. If you know how this could be done let me know. Thanks.

[Bill Sherlock]

Austen,

Guessing you might have a problem with your throttle linkage, may be binding or hooked up incorrectly??

Should be able to convert a rope start to recoil start by replacing the rope start pulley with correct hub for your rewind.

Bill

[Austen]

I got my Jacobsen lawn queen started finally after a couple of days of trying to get it started again. I couldn't get it started again after I throttled it down and wouldn't start it again. I tiped the mower on its side for a little bit to do some work on the starter recoil and when I was done I tried to start it, it started right up and I had it under full throttle. When it started it was at an idle and then it took about 10 seconds for it to reach full throttle. I was wondering why it would have done this? I think this is why it wasn't starting because for some reason it wasn't getting enough throttle so it was like starting a cold engine at an idle. I going to rebuild the whole thing some day when I get the time so right now I'am just fiddiling around with it trying to get it to run right so I can mow with it a little bit for fun until I get the time to rebuild it. If you have any suggestions please let me know. Thanks.

[Andrew Mackey]

I believe the Jacobsen 4 ball starter requires a different crank shaft. Jacobsen only made the 4 ball starter for a few years, and then had to go to the pawl and cup design, as they were infringing on the 4 ball B&S starter patents. The starter cup and pawl were made under license by Jacobsen, to Techempseh. Is it that the throttle does not open or the throttle opens and the engine does not accelerate If the throttle is not opening, then check the linkages for binding. I have found on my 321 engines, that sometimes the governor spring gets rotated on its mount screw, and it will bind on the bottom of the fuel tank mount. Check that with the throttle in the full speed position, that the throttle shaft on the carb is fully opening. You should see the throttle open fully and smoothly upon advancing the throttle lever. If the throttle motion is jerky, or the throttle does not open fully, check:1)throttle shaft for play, 2)linkages and attachment holes for wear and play, 3)governor shaft and throttle for lubrication and dirt. The air vane governer sometimes binds from dirt drawn in by the cooling system. If the throttle opens and the engine does not accelerate, or actually stalls, check the following: 1)Exhaust ports on the engine - the 321 type engine, depending when built, will have either 3 or 4 exhaust port holes, approximately 3/8" in diameter. If these ports are restricted by carbon, the engine will perform poorly, and will overheat, resulting in power loss. To fix, turn the engine to bottom dead center. Remove blade disc, muffler, and spark plug. Take an air source, and supply a gentle flow of air thru the spark plug hole. Gently use a wide flat blade screw driver and scrape the carbon from the ports until all are clear, by turning the screw driver in the ports like you are turning in a screw. Wear safety glasses, to keep carbon particles out of your eyes. DO NOT pry the screw driver in the ports You will damage the cylender wall, which in turn will cut up the piston and rings. The purpose of the air is to keep the hard carbon particals out of the cylender, and away from the soft aluminum piston. While you have the muffler off, and the #2 item to check, is the muffler itself. The muffler on your machine is in 2 halves. It has a serpentine pathway for the exhaust gasses to travel thru, to get away from the engine. This pathway comprises of a series of metal dikes within the muffler, with 1/2" holes in them to direct the gasses as they travel thru. These restrictions have to be cleaned once in a while, for optimum effeciancy. Clean the interior of the muffler as well. 3)check the engine crankshaft for play, and the condition of the crankshaft seals. Play, or bad seals will greatly affect performance. 4) Check the carb for proper set up: At high speed, open the main jet (turn out main screw) until the engine double strokes severely. Lean out mixture (turn in screw) until the engine hits on every stroke (sings like a BEE). Back out screw until the engine just starts to break up (you want top end mixture slightly rich). Idle down engine. After RPM stabilizes a few minutes, richen idle mixture (turn out idle mixture screw), until engine double strokes. Turn in idle mixture screw 1/8 turn in 1 minute intervals, until engine just runs smoothly, an occasional missed stroke is OK. The engine should now be fully responsive, accelerating smoothly until governed speed is reached, at which point it will double stroke, or miss full song. When the engine is loaded, or cutting heavy grass, it then should hit on every stroke.. The reason for setting high speed rich, is during load, the fire in the cylender is contained for a longer period, and there is more power derived from the fuel-air mixture. If the engine is set up to sing like a bee under no load, then the mixture, under full load, becomes too lean. This condition leads to accelleration stalling, and possibly engine cylender damage. This goes for all 2 stroke engines, not just the Jacobsens. Chain saws, especially high performance ones like Sthil and Husquvarna are especially suseptable to cylender-piston melt down, if set up too lean. NOT Lastly, check your fuel. After 30 days, 2 cycle gas loses 1/2 its burning ability in a partially filled container. I, lately have had even straight gas go bad in as little as 20 days. You should be using a ratio of 16:1 (1 cup oil:1 Gal Gas) in your Lawn Queen. Use SAE 30 non detergent or 2 cycle oil only, not the 2 cycle synthetic lubricants. (The synthetics are not made for low speed engines like the Lawn Queen - 500 - 3,000 RPM vs 15,000 RPM+) The sthil's can reach 22000 RPM-no load!
Andrew

[Andrew Mackey]

Austin,
read my reply to your post of yesterday about throttle up
Andrew

[Austen]

Thanks for the information. I think I am running to lean on the mixture so I will dump the gas out of the fuel tank and gas tank I have for it and start a knew one now nowing the right fuel mixture. When I got it running yesterday the throttle was not cinked or cloged with dirt in any way. I made sure of that, the throttle cable works just fine. When I had it under full throttle it took about 10 seconds for it to rev up to full speed. The few times before I had it running it wasn't doing this, it was working fine. I just got a new muffler for and two extra parts engines for it that I found researching of the internet. I got a soaked and cleaned the muffler so I think it's pretty clean in side and also scaped out the exhuast manifold. I will try and clean out the carbon in the engine. My dad gave me the mower, it's been sitting for about 25 years!!!!!!! Like he said it's amazing it does actually runs (when it wants to). When I do get the time I'am going to restore the whole thing and repaint it. For right now I am just trying to get it to run a little bit so I can mow with it for fun so I've been asking a bunch of questions on here that I have had on trying to get it to run better!

[toolazy]

Any chance I can just buy a flywheel and that plastic vane that connects to the carb linkage?

[Austen]

When I was taking my carburator off, I had to disconect the governer. When I did this I guess I wasn't being careful enough and the little coil tipe wire that wraps around the governor broke. This is the little huke that the wire connects on to that's on the carburator. Luckily, I have a couple parts engines that I could replace it with. I don't know if you would want this, but I'll offer it to you anyway. It could probably be sodered, I'm not sure if I still have the other little huke piece that broke off. It's probably usless now, but I thought I would offer it to you anyway.

[Walt in Jaxn Tn.]

Originally Posted by Austen Wilcox

I've been having so much trouble with my Jacobsen lawn queen that I think I'm going to put one of my spare engines on it. For some reason when I put the mower to an idle for a little bit and then gave it full throttle it won't rev up again for some reason. I've spent a lot of time working on it and rebuilding and adjusting the carburator on it that I think I am going to put one of my spare engines for it on there. I was wondering if it was possible to convert a rope start to the Jacobsen recoil with the four starter balls? I'd like it to be original and have the recoil instaid of the rope start on the spare engine. If you know how this could be done let me know. Thanks.

I'm trying to find a rope start pulley for my Jacobsen engine as mine is busted. Would you be willing to part with yours.

--Walt--
waltercableguy@charter.net