Q and A: DIYer on 10/1 Clone Engine

Question for George: Hi George – thanks for the amazing wealth of
information on your site. Its sure helps guys like me who are just
starting out.

Recently bought a new 10/1 and I have a couple of questions

Firstly I am having a hard time cranking it over by hand especially when its hot.
I come up against serious compression even though the decompression valve is in place. There are times when I am unable to turn it over because of this.

Secondly it came with the power solutions 7.5 KW with a 2 belt drive system. The manufacturer Vijay suggests a 1000 rpm for this engine. Is the 2 belt system a decent option for driving the generator?  and since I would like it to run as slow as possible I’m sure i would have to change the flywheel as well to get my 60 HZ.

Thanks for your help George

George’s Answer: Hi Paul, reading your email gives me confidence you’ll do just fine with your project,  your mention that you are ‘just starting out’ is key. This will likely encourage you to read more and learn more about your generator set.

I don’t push the CD, but if you don’t already own it, there’s years of articles, pictures, ideas, diagrams and more on it, and much applies to what you own.


There are about three popular clones marketed as 10/1s,
some are direct injected, some are indirect injected, piston materials can be different,
etc.  So don’t assume yours is just like another one your read about.

When you are working with a new engine and have not yet developed an ear and eye for what’s normal, it’s best to assume nothing and document your engine.

I recommend you remove the crank pin bushing and inspect the
top shell BEFORE you run any Lister Type new to you.

I’ll assume many things here for the sake of time and ask
that you drop the belts and isolate the engine before you attempt to diagnose
the problem.

Always remove the air filter, this allows you to shut
down the unit with the palm of your hand placed over the intake if necessary.

Now… check the valve clearance and assure there’s some
daylight between the valve cap and the rocker tip.

Set the decompressor, and turn the engine over slowly, do you hear the air gush from the exhaust? Is the decompressor adjusted correctly and does it lift and hold the valve off its seat far enough to turn the engine over fast by hand?

Remember! There are plenty of decompressors destroyed WHEN
they are adjusted too lift the valve too far off it’s seat.  The piston kisses the valve top hard and the push rod passes it along in a less than loving way to the little arm that holds the
tappet up. Since it’s cast, it can break in half, and leave you to source a new one 🙁

So there’s a start. I had one customer who was in the process of a rebuild BECAUSE he couldn’t start his generator… he assumed too much and never dropped the belt. Of course the problem was on the generator side, and even the load on the generator was still in place! This same operator could never be bothered to mount the CD yet alone read the featured article ‘listeroid longevity’.

As I say:  These engines are for DIYers…. by our very nature, we are curious,  we can not help ourselves,  we are driven by some compulsive disorder (AND our past mistakes) to read a little, and to learn how it works before we attempt to fix it. Part of this behavior comes out of being the thrifty people we are, we learned early and sometimes the hard way that there’s always something more important to spend our money on than fixing things we broke 🙂

As for your question about 1000 RPMs.. these engines are very much individuals, some well balanced, some are more like jack rabbits on steroids.  I find that many if not most owners of 1000 RPM engines choose to run them slower, they experiment, they note that sweet spot and then measure the RPM. From there they calculate the size of the generator pulley.

Your question about the drive system. I should recuse myself as I am no fan of VEE belts. This doesn’t mean they’re bad, it just means I don’t think they’re best. If you read more of my writings, you’ll note what I say about ‘KISS engineering’. It’s important you use wear parts that are standard and easy to find in your market. Here in North America, the Serpentine Automotive belt is everywhere and works very well off large flywheels eliminating one pulley and losses. It also wears like iron!  This is NOT the case in India, vee belts are often the only stock to be found, so we should expect them to engineer as they do for the sake of sourcing belts.

And… just to mention! We all need credit those Old Iron Enthusiasts. It was likely an hour after one of them bought the first American auto with a serpentine belt and alternator that they pulled it from under the hood and mounted it to an old large flywheel engine just to see how it would work 🙂

Hope this helps you get started…and all the best….

George B. Utterpower.com


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5 Responses to Q and A: DIYer on 10/1 Clone Engine

  1. John says:

    Great write up as usual! Only one comment though, with regard to sticking your hand over the intake, for use as an e-stop. You can do a lot of cellular damage to yourself! And I’m not talking about your phone. 😉

    Try stretching an old inner tube over an appropriately sized block of wood, then screw an old drawer pull handle to it. Presto! Safe e-stop paddle.

  2. George B. says:

    John, I said to use your hand, not your Pe___! 🙂
    All kidding aside, I guess it depends on your hands and the amount of callous you have, I don’t use gloves for anything, maybe that’s why I have so little trouble.

  3. George B. says:

    OK, I got soem feed back from paul, but apparentyl he didn;t know to scroll down and post his reply here.. so I will ….

    Thanks George, your response was detailed yet simple enough for me to understand.
    The 10/1 I picked up came with an ST 7.5 with dual pulley system and also double pulleys on the extended shaft of the listeroid for the V belts. As I mentioned, this was slated to run at 1000 rpm and all seems to work fine after I powered it up today. However I am not thrilled with the drive system for a number of reasons. Also I want to slow it all down – maybe 650 RPM . Do you sell the single wide flat belt and correct pulley size for the Gen, head that will mate and stay on the heavy wheel of this model listeroid without slipping ? The wheel is obviously factory painted green at the moment, Im open to suggestions from you or your readers how to proceed.
    kind regards

  4. George B. says:


    There’s a lot of information on utterpower, and as I said a VERY concentrated amount of the CD. Search engines like google make it easy to search for utterpower stuff. try this on a google search utterpower-pulley
    you should find a lot of info.

    Flat pulleys are pretty much a thing of the past, we’ve foudn the serpentine belts are great and I just happen to supply a very well made pulley (while they last). I reccomend the 8.4 inch serpentine pulley, it runs right off the flywheel!
    See this page https://www.utterpower.com/pulley.htm
    Currently, there’s a few pulleys left. The pulley, the bushing for that 7.5 ST head, (38mm) and the metric bolts to attach bushing to flywheel and gen shaft are $176 dollars delivered to your door in USA. Prices can change! You’ll need nothing other than an inexpensive belt from the auto store.. I have one customer with years of daily runs on the same belt! … six or seven years!

  5. Bill knighton says:

    I got a serpentine belt for an 80s mustang and an allman drive pulley because I guessed that autozone would have the belt in stock and they did. I’m off grid and had this engine for 5 years and this belt is in better shape than the much newer one on my car. It doesn’t have little cracks across each micro v section. I don’t know when it’s going to break at this rate.

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