Generator prime mover

Great explains, you are doing Wallace.
One of my OHC Honda mower engines uses a neat manual set; then running auto work-off choke. It uses running engine vibration. Engine running a small carb incorperated vacuum pull off. The other walk-behind mower with a CA-spec no touch fully auto coke system really only works well at 50F and above.

Single cylinder engine vibration “ameliorate’rs” are sure worthy to get rid of alright. More mass to have to hand or tiny electric starter turn over. Many engines will weighted shaft bearing pockets waller-out.
And ALL engines you are creating more wear shed particles into the crankcase oil.
What’s a little buzzie between friends, eh. Long as it’s not handle bar hands numbing.

ALL of the piston side trust; crank angle; bore stroke factors; valve-flow to cylinder filling factors you are optimizing for are completely correspondence to the V-8’s Ford/Chevy/Dodge max. naturally aspirated horse-powered small block versus just using a mildly warmed-up large block.
I’ve know lifetime a few who did modo building up truck towing small block convinced of advantages. That they would wup the truck big-block boys. For a time, match, maybe so. Not for any reasonable service life at all though. Heats&wears take a toll. A big-block spreads theses out. A small-block concentrates these.
Steve unruh


I ran it again here for a third time and its running nice, automatic choke is not set up and I changed the oil, once its cool I will go in and check torque and valve lash.
I have about 15 minutes run time just long enough to make sure its not a dud.

Now with some fresh oil in it I will leave it alone and not screw around until I can get a load on it.


Final major assemblies are now together.

Whats’ left.
3 wires to connect between the poles and the controller.
8 bolts to bring the engine, the end bells and the frame together.
4 bolts to mount the controller to the frame.
1 nut to tighten between the armature and the crank.

I am not very impressed with the threading job on the crank.
It should be 3/8 NC but its s rough over cut of the partial remaining metric threads inside.
I left instructions to the machinist to cut it metric if required… what ever was easier.
It was not easier to convert this to SAE, he screwed up the threads but lucky for me there is enough to run a piece of ready rod in place of the factory bolt.
This was not my first choice but compromises are everywhere…

Automatic choke is now working.
I ran a quick test…
Its no hell, not as nice as the Sisson but it works.

The whole machine is getting heavy now.
This is probably the last time I lift it myself.
Another 40 pounds of iron to be added and that will be more than my back is rated for.


Just one wire left to connect for a test, that would be the ignition wire and I have to consult the generic print to figure out exactly where it goes ( or the little guy that controller is pretty near the same ).

Today was a sweltering hot day full of problems, but I made it all work.

If you look all the way over to the right of that terminal strip you will see a missing screw ( not me ! )
Thats’ number 5 and according to the generic print its the connection point between the magneto and controller.
Next to it are ( obviously ) 3 and 4 these are the make to run terminals.
Closing a switch on 3 and 4 energizes relay CR ( nearest in photo ) and this begins the starting process and the main solenoid picks up and motorizes the generator through the series coil and armature.
A small thermal relay monitors cranking time and a heavy duty Kilxon provides over current protection.
The generator has to fire up the engine before the timing function trips and shuts the CR circuit down. ( not denergized but some of its functions )

But if everything works as intended the engine starts ( :wink: !!! )
Then power flow through the start circuit reverses as the engine picks up speed as the main exicter starts to generate DC field power.
CC relay in the centre senses the DC field come to life and heavy loop of wire that originates at the start solenoid has the current reverse it it.
This current when flowing forward inhibited the closing of CC and now that the exciter is generating power it has reversed direction and CC relay picks up.
This disables the CR starting relay functions and brings the safeties in ( if they are wired up like oil over temp ect )
Way over at the end is a steel can, this is an old Autolight 4001 voltage regulator and it with the resistors you see controls battery charging voltage.

Thats all there is in a TI-8 controller
And probably the most simple system I have ever seen to start a generator remotely and still provide all the required protection
If I can find a way to copy the print over for this I will post it.
Its a very good simple system you could adapt to just about any other generator if you have access to some relays and general purpose parts

Here is a photo of the print kind of small and hard to read.

And I made up a nice little remote for this that has some indicator lights to tell you if the DC is on ( DC battery and control power exciter power ) and AC is being generated.


Zero hour.

The first cranking test and wiring check.
It rolls over the GX240 without issue the exciter start circuit works.

Mislabeled wiring 5 is not 5, 5 is 6???
Have I mislabeled a wire for the ignition?
This is why I did the rolling test what I thought was 5 was in fact 6 and I would have wired the magneto to external 12 source ( to power a valve or electric fuel pump )

But the exciter rolls.
Now I just need to summon the courage to put fuel in the carb and hook that ignition wire up to the real 5 and pull the toggle switch to start.
The set should run…

At 5:30 after exhaustive checks and reading I put fuel in it and turn the selector to start.
Everything worked I got 115 volts ( not bad ) the voltage increased to the battery from 13.5 to 13.7 indicating that the charging system seems to be ok too.
I toggled the switch to stop and it shutdown.
A couple more times and I increased the governor to raise the voltage to 125v AC no load.

Now the storm clouds are coming in and my day is done.
Once its cooled I will move it back into the shop and maybe tomorrow I will load it up to 1500 watts and do some more checks and tests.
My biggest concern is the brush rigging at this point and anything that may come lose and blow this up in my face.

I want to play with the governor sensitivity and start looking around for a air filter for it.


SO how did that other head turn out the one I stopped talking about a while ago?

Here’s how.
I finished it tonight.
Its not very pretty.
But I did what I could with the porous weld and I sculpted the Intake port to flow more on one side that the other hopefully to introduce some swirl.

The valves are too big, they will kill velocity but nothing ventured nothing learned.

Life is full of suprises…
Maybe the big valves will work in my favour and help with the minor shrouding issues and the swirl I put into the port.
Maybe the ugly welds will not create hot spots.

Maybe this works out and its a fast burning head.
If its what I hope for this is a logical thing to do to clones on wood gas.
The fuel burn tests on the new generator will tell me if I am heading in the right direction.
So will a natural gas carb and some tests on that.


The gas head…
I did more work too and refinished the surfaces today and assembled it.
You know that is just not attractive looking at all.

But the proof will be in the puddin…
As you can see I have plenty of quench area both side I can remove if needed to get the right compression ratio.
Now I need to measure it and calculate my CR ratio

I started laying out a brand new producer to feed this thing charcoal all made of of LPG tanks and I have some interesting new ideas I am going to try too but the main focus for now is gasoline >>>> NG >>>> Producer gas in that order.
Rough math tells me I should be aiming to run about 10:1 and this will let me move between fuels without a major engine modification ( but a timing change… and I have a very clever idea for that )


Moving ahead:

Load test.
1500 watts about 13 amps and it runs just fine plenty of power to spare.
The rings have seated now and the engine is running as I would hope.

Governor is causing me some grief.
I have a mixture of parts from different engines and no idea what combination will work and what will not.
I am frustrated yes it runs great but the engine is hunting and nothing I do seems to work to get the sensitivity right.

Email from Koshin America they built the generator as configured with the original idle control system and asked about a replacement board and parts listings.
Waiting on a reply…
There electronics will work with the EL-8 controller.
But I am not sure the governor wheel the nice Chinese man many posts earlier sold me will with the the Honda and Koshin parts.

I am going to try and back track this.
I am going to try and make the Loncin ( Chinese clone ) snow blower engine governor components work.
If I can get stability out of them I will try and adapt the Honda and Koshin parts with them.


Today after making some changes we have tenuous stability at 1500 watts 59 hz and 116 volts output.

Its not perfect but it does not hunt.

Time for a full pull and I have thought up a clever way to test my fuel consumption.
I am going make my clear fuel line in two place and pull the end from the tank and time how long it takes to burn from one mark to the next.
Then I will compare this to the old Kohler plant, then I will compare this to the gas head on 91 octane fuel.

From here I should be able to judge if this thing is living up to expectations.


Loaded right down to 28 amps at 110 volts yields just a bit above 3000 watt the name plate rating of the generator.

Power to spare with a little movement left in the governor arm.
It would be nice to have a little higher output than 110 at full load but that is the nature of this type of machine.
It has no regulation you get what you get…
I may be able to boost that a touch with a capacitor.
This will mildly boost the voltage and correct for any reactive power loads.

Was it worth it?
Won;t know until I get the high compression head and the NG carb on it…
Will it still pull 3000 watts?

And of course I have to try it with a gasifier.
I am already thinking about that a simple fire made from propane cylinders I have been hoarding for just such an application


It’s been a great project to follow so far, very inspiring and instructive. Just for that sake I rate it as worthwhile.


Its been very frustrating.
But I must confess I do like the end product.
Its very smooth, its got power to spare, its very simple in design and construction ( except for all the parts that wander off in to the weeds like my attempts to get the load control system to work ).

As long as it stays dry and oiled to prevent corrosion it can sit as long as required, then at the flick of a switch it should start. ( it will never need exercise like a modern plant )
With a snorkel on it and the gas head ( project pending ) it might perform well enough to pull nameplate power out for the generator head on producer gas.

How can I post a video?


I understand that you have to upload the video to YouTube, and then copy and paste the link in your post. Be sure to leave a line of space above and below the link, for it to show the video thumbnail.


I will look for a website that hosts video.
I have not used YouTube since they changed and would not let you edit or delete your own video.

I really really like the way an exciter cranked generating set starts.
just a few clicks of relays then the exciter cranks it up.
WAY up and your running, no fuss no starter noises just zero to go in a few seconds.
I would like to show that.

Since I can not find an exciter cranked Kohler here is a nice LK205 that operated pretty much the same only in a lower speed heavier duty unit.

Added later
Silly me i posted a video of a K331 exciter cranked unit ( a 3rm23 four pole unit… And I even have one of these ( in the que for restoration )


So the hunt for parts goes on.
I want an idle control board, but I got a quote of 107 USD plus shipping ( and god knows what else happens )
This looks like 150 or more Canadian by the time the dust clears.

But this is what I want the board to do.
And I am not apposed to making one out of spare parts.
In for a Penny in for a pound I think the smartest thing to do is build my own ECM around this problem and add some electronics compliments of the Arduino project.

I still need an airfilter.
Now let me tell you something about parts.
No one stocks them anymore, but the rental shop guys often sit on a few just incase items.
I need a Honda filter cover not the whole assembly and the best I could manage from a guy that had a stiff to strip wanted 50 bucks for the whole assembly.
I said Nay… 25 maybe ( we have known each other for 25 years or more and play this game often )

Well Ebay has a clone part I am good with so I will order this.

So what is left to do on my TOO DO list is make a plate to shift the rear engine mount forward and remount this to the 1960s Kohler engine cradle…
I need to build an ECM ( from Arduino ) to monitor load and alarms ( like low oil level, under speed, overtemp, low fuel, Liquid fuel > gas change over, and what ever else I can think of ).
I may as well make use of the idle control system and rather than pump 25hz at 60 volts into my home at no load I will run a square wave inverter… a wee fellow, to supply 1000 watts to keep the heat on the circuit in the house until a load is detected, then I can switch to generator after a ramp up and switch the load.

Its like putting a computer in Dad’s 66 Rambler…

Last night ordered more parts from Aliexpress.
Fuel cut off solenoid and new air filter assembly .
I tried to source this locally a long with idle control board but was told they just can’t help me without part numbers. ( or wont try very hard ).
Cost for a complete new air filter assemble 17 USD shipped to my door in 15 to 30 days ( slow boat ) locally sourced new parts 50 dollars Canadian.
Replacement fuel cut off Solenoid not in stock local. ( I am told everyone here just snips the end off when they fail rather than repair and replace what is essential an anti-diesel part. But I will need this to shut off the flow of gasoline when I switch to gas )
Aliexpress price 7 USD ( Ship China air mail to door free in 7 to 14 days )

The Original distributor ( Koshin America a reputable manufacture of quality pumps and power equipment in Japan ) has been able to find a board but its REALLY expensive at over 200 bucks Canadian.
I thanked him for his efforts and started to look overseas for something compatible but I will likely just end up using an Arduino Nano.

What lessons have I recently been reminded of?
No one has parts, keeps parts in stock and or can just look at a part and say I know what will work.
No one keeps used parts unless they are for personal use like the rental places.
Those guys strip and recycle the parts from a stiff because they understand the cost of simple repairs.


You can sign up on youtube using your email address. Pick your own password
for YouTube logins. It’s real straight forward.

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When YouTube was new I did that, then YouTube changed and I lost control of my intellectual property and I can;e delete my material.
Never again will will give up control of material for Corporate America to make a dollar.


I agree that youtube has gotten very greedy and money driven. It made me angy enough to delete all my videos a while back when they changed their policy to freeze out all the small time posters from collecting revenue on the adds. I have since made a few just to share things with all of you guys.
So! I just tried it just now and I am still able to delete a video.


I wish I could.
Trouble is I have a hard time understanding how all these things work now.
I never made the leap to cell phones and only use computers to read the news.
This forum is the only place I ever really post and the controls are very simple.


Just out of curiosity, Andrew, what is a “small time (youtube) poster”?
I consider myself to be in that category,(less than a million total views and less than 3000 subscribers) but things seem to be working okay at this end.
I do know that it is kind of hard to keep up with the system changes that youtube makes. I get frustrated with it fairly often.
On the other hand, my videos are all of the same :“share things with all your guys” type, so I really don’t do it for the tiny amount of money that I get.
In fact, I put off “,monetizing” my channel for years until one of my kids bugged me until I did it.

Pete Stanaitis