TOPIC: Small engine Grooving

I did my dad's 5.5 HP Honda mower as my first groove, and it starts easier than it did new, even when it's cold. Never got around to the snowblower, but there wasn't much call for it this winter.
The mower gets used in the autumn to mulch leaves, as well as keeping the grass even during the summer, and if our maple leaves are anything like Ystervark's grazing grasses, we had the same experience with this machine: it chews things up more easily, using less fuel.
I'd bet you would be able to squeeze longer run-time out of a generator that was grooved, and maybe (I'll have to look into the electronics) make it handle greater loads or deliver more current while using less fuel.

After the disappointing fuel economy run with the Nissan today I am more convinced than ever that the way to go is doing small engine grooves........

Greg and Tracy.

Thank you for the input. I will for sure start working on getting more data with generators and mowers soon.............

Please keep us posted! Static engines like generators interest me from the benchmarking perspective of the groove...id like to see how the mods scale up in terms of efficiency as engines get bigger...

Ystervark. That Nissan could be on the rich side, though it doesn't sound like it, except from the run results. Check the turns out for the idle mix screw, and the turns in after first contact for the idle speed screw. Check fuel pressure too if you can, it may need a Weber pressure regulator. Remember w/ carbs it's all manual adjustments/jetting, as well as the Ignition settings. Usually more work/ time than the injected computer controlled ones. You have nothing to feel ashamed on w/ that Nissan, there is likely more economy to be had w/ it. And there are our "tricks" too...

And Yes, there is an entire World of small engines there for you. I'd expect Owners of those engines eager to get improved economy, and You are their Man!

Keep Shootin', Ace!

Tracy G

In South Africa we have many garden services and golf courses.

I contacted a garden service contractor this week and he is really interested to have the groove done on his 3 lawnmowers and 2 brushcutters. So we will see.

After talking to this guy and hearing his excitement regarding fuel savings maybe it is time to start working in that direction more.... He uses about R 2000 worth of fuel per month and I am sure he can save half of that with the groove. I am planning on doing one engine for him first so he can see what I am talking about then I am sure we will do the rest as well. I told him to do an easy test by closing the fuel tap on the lawnmower while mowing the lawn then timing how long it takes to empty the carb. Then after the groove we will do the same test and see what the results are.

Will keep you posted

What about gasoline powered electrical generators? Other static engines like those used to pump water for irrigation? Lots of stuff like this EVERYWHERE...

Yes Greg I agree. Lawnmowers are my starting point..........I will expand from there

you Go Ystervark!! Remember the plug gap increase too!

Ya-hoo!

Tracy G

Nothin' new here, just bumpin' this thread to keep on front page.

Tracy G

bump again!

Tracy G

Hey Martin, You Da Man!!!

Nice work on the carbs and very nice pics to show your work.
Excellent dude!!!
Glad you got the success you did and to think a little while ago you were waiting forever for
these bits.
I can see why you were so annoyed at the lack of communication and the time it took.
You had plans for these bits and boy did they ever pay off.

Now on to another thought Martin that you brought up. Got me thinking on what you said.
You said that Ron said to use the biggest bit possible. Well seeing that in relative comparison,the groove you did on these carbs is MUCH bigger comparison wise to the groove on a regular TB.
My thought on this goes on these lines. When one steps on the gas, the throttle opens and its the first few degrees that count the most seeing the smaller the TB opens, the more that air is directed into the groove. Anything past 10 degrees is almost wasted for groove use seeing the air is not being shoved into the groove and being compressed. I have been thinking for the last two years that the groove may be more useful if it was larger or moved back a bit from the throttle plate so when cruising the throttle position would be pointing into the groove instead of just when just past open.
My TB is closed at 16 but cruises around 24/25 so that is 8 or 9 degrees past where it does the most good, IMHO.
So maybe making the groove deeper with the same shape like you did with your lawnmower carbs(if that is possible)or moving the groove back a few degrees may give better results.
Just a thought here.

Hey Karl - refresh our memory: is your truck old school cable drive or a drive-by-wire modern TB? What you've just described is basically the procedure for locating the groove in a DBW throttle body. It has to be downstream to compensate for the amount the computer opens the throttle plate for the idle air adjustment, as I learned when I did mine.

we should continue this convo in a new thread so we don't distract from the small engine topic...lead on sir!!!