Following Ron's video on small carburetors/generators I applied what I interpreted as Ron's 1/2 groove. I may have it wrong put I applied the small bit groove between the 4 and 8 o'clock positions. I did make adjustment on the idle screw to allow for default position of the throttle plate.


The target subject
a 3050 watt 7HP Chicago Electric 4-cycle generator with a 4 gallon fuel tank.

prior to the groove I ran 1 oz of fuel through the engine

run time: 48 seconds (keep in mind I had already prepped it for the winter)

Applied the groove as I described above and re-installed

and again, 1 oz of fuel through the engine

run time: 70 seconds

net gain on 1 oz of fuel: 22 seconds

It may not seem like a lot but if you do the math...

1 gallon = 128oz
4 gallon = 512oz

So, for a 4 gallon tank
Total run time pre-groove 6.82 hours no load

Total run time post-groove 9.95 hours no load

Net gain post-groove 3.13 hours no load.

Now for those of you not familiar with generators, at idle the governor is jockeying the idle to keep the engine running, since there is no load for it to manage. When you put the generator under load, the governor on the engine will adjust its idle speed to maintain the power output on the generator.

This will actually put the throttle plate into a fixed position in the groove which I am speculating at this point will improve the runtime with the groove fully engaged.

I'll update this post after I do a load test... easy enough.

Here's the update,

Had a 60 watt bulb plugged into the generator which allowed it to maintain constant rpm.
1 oz fuel post-groove, under load - 82 seconds

Without allowing for the small potential error in my measuring and I tried to be close

That is a full tank run-time of 11.66 hours under a light load

Leaves a potential 4.84 hour run-time gain on 4 gallons of fuel.

Karl Fortner
Gadgetman Tacoma (Youtube)

I totally agree as I grooved my 23hp scag mower and can mow one third longer on same amount of gas full throttle. Not only that the grass can be tall and thick and it cuts with no engine strain. Dan gadgetman MO.

Makes for some pretty interesting calculations when you try to determine how much error could be applied to the fuel measurement. Not even close.

I'll actually be interested to see what my lawnmower is going to do the next time I actually have to cut the grass.

Karl Fortner
GadgetmanTacoma (youtube)

SCORE ONE KARMA, KARL!!!

You will find, as demonstrated by repeated reports, that under load and at higher RPM's, the efficiency will increase even further! You will also find that an increased gap on the spark plug will give even greater gains.

My single cylinder is now at 300%. All I did was cut The Groove and regap the spark plug. Stock, it was .024". Now, it runs like a champion at .040"!

The wider the gap, the more power required to jump it. Since most coils produce way more power than is actually delivered, this will allow you to get the full benefit of the coil's rating.

Try that after you do your under load test and see what happens!

Great work!

Ron

Here's an update on the generator

Original spark plug gap: .024" (realized I didn't have a feeler gauge... do now!)

Adjusted spark plug gap: .040"

Under load:

I ran one ounce of fuel through and the numbers didn't change all that much.. was at about 70 seconds.

Decided to give it a longer run time for better averaging, so I increased the fuel to four ounces.

The results of that are as follows;

4 ounces of fuel - 8 minutes 54 seconds run-time

Broken down that 534 seconds or 133.5 seconds / ounce

applied to four gallons would be 68,352 seconds, or..

4 gallons = 18.98 hours run-time under load

That is FREAKING INSANE!!!

Original run-time, based on one ounce of fuel
pre-groove 6.82 hours no load

Ultimate difference under load
post-groove 12.16 hours increased run-time.

I checked the manufacturer spec's on this generator
and this is the total run-time stock.

4 gallons @ 50% load 9 hours.

Now, the really cool thing is that I don't see me doing anything with this generator that is going to put it @ 50% load. I run a computer, lcd monitor, audio mixer and video switch... maybe 350 watts max. I'm good with it!

I decided to pull our old generator outa the garage and see what the groove could do for it.

Its a Coleman powermate 5000 watt generator. It has a 5 gallon tank.

I ran one gallon threw it pregroove under load.

I used a lamp with 3 13w bulbs.
And i put another lamp with 3 250w infrared heat lamp bulbs.

Off of a gallon i got 134 minutes

Then I took it off and grooved it. and reran the test with the same load.

off of a gallon i got 168 minutes

25.4% increase

I haven't played with the spark plug yet but when I do you can expect that number to go up!