Author Topic: One lung FM Z 1 1/2 HP  (Read 6504 times)

Offline Admiral_dk

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Re: One lung FM Z 1 1/2 HP
« Reply #30 on: June 04, 2024, 07:14:10 PM »
Just to clarify : My closest experience to your request is a Suzuki LS650 - A single cylinder Four-Stroke, with a 40mm. Carburator. I'm not sure (no rev counter), but I guess that max. RPM is around 5-6000.

Your Honda Carb will flow approx. a sixth and your cylinder volume is ~25% larger ....

Rough guestimate ; it will allow your Engine to run up to somewhere between 1-2000 RPM (everything else being Equal .... But they are NOT).

For my olde LS650 to go down to 500 RPM - the Throttle would be closed so much, that I can't see any hint of light through it (that is almost the case for 1200 RPM).

I must admit that I'm rather surppriced that the Honda carb don't even give a hint of running when Choked  :headscratch:

There are a few here that actually has full size old work engine and I had hoped that one or two would have chimed in by now .... but then again - a good number of those don't even use a carburator ....

Per         :cheers:


Offline Geo46

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Re: One lung FM Z 1 1/2 HP
« Reply #31 on: June 04, 2024, 09:57:35 PM »
Well maybe I not using  the carb right, sounds like you are saying I should be closing the throttle completely, to me that sounds like no fuel would flow into the cyclinder, I have 6 months to figure this out, your correct about the older engines not using carburetors they use mixer which is a form of carburetation
Geo46🇺🇸🇺🇸

Offline Admiral_dk

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Re: One lung FM Z 1 1/2 HP
« Reply #32 on: June 05, 2024, 09:18:10 AM »
OK - I should try to explain a few things better.

A number of old engine ran on Town-Gas (or other kinds of gas) - not gasoline - so no carburator.
Others ran on Oil - like old Hot-Bulb Engines - were the oil was injected into the Hot-Bulb (low pressure) - again no Carb. The Kerosene Engines had somekind of Mixer as you mention.

Starting Procedure ; no two Engines designs has the exact same best practice - but in my experience tells me that it is almost completely impossible to start a cold engine with an open Throttle.
In my youth, I used to slowly open the throttle during cranking, from closed to a bit over fast idle ....
If no succes - slowly closing again. I used to be able to hear when I was close to succes - Electronic Fueling and Ignition, has decreased my abilities over time ....

Unless the weather and Engine is warm - I also expect you to have to use somekind of Enrichment function - like a Choke - for the Engine to fire.  Almost all those devices do NOT work if you open the Throttle much over Idle.

As you haven't got the Carburator dialed in for your engine yet - you will have to experiment with the exact Throttle position for starting.

I noticed that your Honda Carburator includes a Fuel valve - I hope that you have it in open position when trying to start the Engine. I mention this as I have never seen any other carburator were this valve is build into the carb itself.

I hope that I'm not telling Granny how to suck Egs  ;)

Best wishes

Per

Offline gipetto

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Re: One lung FM Z 1 1/2 HP
« Reply #33 on: June 05, 2024, 10:45:49 AM »
when i need to find out if a carb is switched on or not, i simply remove the bowl to check is there a fuel flow. this also works to clean out any bad fuel.
There's no reason you can't run ganged carbs to get more fuel and air, if the honda carbs are easy to come by, and you feel like fabricating a suitable manifold.

Offline Alyn Foundry

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Re: One lung FM Z 1 1/2 HP
« Reply #34 on: June 05, 2024, 10:54:26 AM »
There were 1000’s of this particular engine manufactured during the early part of the last century. The carburettor is quite a simple affair. A small box along side the Venturi carried enough Petrol/Gasoline to get the engine hot enough to vaporise its running fuel, Paraffin/Kerosene. The front of the Venturi is covered by a spring loaded choke plate. The air is then drawn across the adjustable jets in the Venturi proper. As the Venturi opens out the air is met by the throttle plate ( Butterfly style ) which is fully open when starting. This throttle plate is activated by a centrifugal governor fitted in the halftime gear.

This engine originally had the main fuel tank mounted between its skids, underneath it. The fuel was drawn up through a non return valve. Your engine has a gravity fed fuel system.

Only a week ago a carburettor was being offered, complete with both fuel jets for $15.00 and shipping. There are several FB groups running over the pond for the vintage stationary engine movement.

You could fit a fuel check valve in the line which would allow you to gravity feed the original carburettor without it constantly running. These were fitted to many Asscociated Manufacturers ( Amanco ) engines that had the fuel tank mounted above the carburettor.

 :cheers:  Graham.

Offline Geo46

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Re: One lung FM Z 1 1/2 HP
« Reply #35 on: June 05, 2024, 12:40:01 PM »
Good morning, I do get fuel to the carb, I will try closing the throttle, never would have considered that, I am thinking of increasing the main jet size to the largest available, won’t be for 6 mths. But still need more suggestions. This is a work in progress.
Thanks
Geo46🇺🇸🇺🇸

Offline Geo46

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Re: One lung FM Z 1 1/2 HP
« Reply #36 on: June 07, 2024, 12:46:20 AM »
Another question just came up. The GX160 comes with 3 gaskets which is the correct one for our setup, 2 have a small a small hole which we assume line up with the small port,
Geo46🇺🇸🇺🇸

 

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