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Author Topic: Advise on china "M" series hit and miss small engines?  (Read 499 times)

ShadetreeMotorcycle

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Advise on china "M" series hit and miss small engines?
« on: October 27, 2020, 08:52:49 pm »
Ok, I have been bitten by the bug to purchase a China M series and try to tune for lowest possible hits per min.
   I am wondering if there is a favorite model? I prefure the horizontal versions...the M90 looks the most simple...the M92 is the best "looker" in my humble opinion with the extra brass and flying ball governor...the M94 has cooling fins on the head but I am unsure of the other differences....so my question is: Is there a model with the most potential to run slow? Anything I should avoid?
   I have been inspired by a few videos...I hope to wind some softer springs, probably lower compression...may try to add a brass or cast iron belt pulley to add rotational mass to get longer coast...look for drag in the engine.
   I also plan to spruce up the model, likely a paint job and a heavy base to keep the model from walking away...I may try them all if I can find good deals, but was wondering if there was a more desirable model....It seems the newest versions of the M90 come with a better spark plug boot, these are the type of things I am trying to learn about but also wanted to know if there was a model that has more potential to run slow? Thanks for any advise!

ShadetreeMotorcycle

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Hmmm....it must be a secret.....

Nick

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Haha, I’ve only ran the M90 but think the M92 is the best “looker”
Nick

Particleman

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I chose m94 because it looks like the simplest. I'm a firm believer in KISS  (keep it simple stupid)

ShadetreeMotorcycle

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See...there ARE opinions...thanks guys!  I found a good price on M90 but it appears to be old stock as it has the clear spark plug boot...I was hoping to find the upgraded one for a good price.

Jim

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I'm pretty new to these engines after recently taking delivery of two, my knowledge of these engines has all come from the members here by reading through all the posts and gleaning bit and pieces of choice info.
There's some really knowledgeable H&M guys on board here.

Look forward to you receiving your engine(s) and the mods that you do, I'd like to make a larger heavier base like you mentioned also.

You might find this thread interesting to read -
https://www.officeofsteamforum.com/general-discussion-scale-model-gas-engines-hit-miss-throttle-governed-non-compression-etc/m-90-modification/
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Jim

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RedRyder

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The M90 may be the easiest to run slowest and coolest.

ShadetreeMotorcycle

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Thanks for the tip on the M90 Redryder!.... I actually saw your Youtube videos about tuning and lowering compression on Youtube Before I found this forum....it was your videos that inspired me to order a China hit and miss engine!
   The link mentioned is very nice...I hope to get even slower idle.
    I Did win the bid on an M94 for a decent price...So I got one coming...who knows how long it may take to get here...I am still on the hunt for a nicely priced M92 AND M90 so I will get at least 3 engines....I may try a M91 vertical but they seem to go for more $ and I like the exposed crankshaft look of the Horizontal models....If anyone has tips for finding the best prices it would help as I need so many...lol!

ShadetreeMotorcycle

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Re: Advise on china "M" series hit and miss small engines?
« Reply #8 on: November 01, 2020, 10:11:50 am »
Well,...My M94 cleared import customs on Saturday, I am hopeful that may mean it's only a few days from delivery.
    The other good news is I won the bid on an M92 today!!....I wanted both a flying ball model AND one with Flywheel mounted weights....So...now I just need to learn patience for engines to make the long journey....can't wait to break out the wrenches and start tinkering/tuning!

Nick

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Re: Advise on china "M" series hit and miss small engines?
« Reply #9 on: November 01, 2020, 10:13:22 am »
Great news! Can’t wait to see what you do with them  ;)
Nick

ShadetreeMotorcycle

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Well...."Some" of my engine supplies rolled in today, I am collecting goodies so I can run my engines when they show up! There is a quart of MM-oil....that "seems" to be one of the favorite oils to mix with the fuel.....there is 2 eye dropper for dosing oil mix...the yellow AA batteries are blanks if I want to drop down to 2 cells vs 3 cells...the syringe is to get fuel into the tiny fuel tank...and the Colegate whiten formula toothpaste is for brass gear teeth polish...they even admit there are micro abrasives in the formula on the box...plus your engine will smell minty fresh!....just need fuel yet I think....got to decide between Zippo lighter fluid and Coleman camp stove fuel....have not determined which is better running or lower smell.....
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Adirondack Jack

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FYI, though some swear by Coleman, I found a series of pretty scientific shade tree tests of gas alternatives. This guy carbon cleaned engines before and after runs, used infrared thermometers, tach readings under load, even a see through head on a four stroke to compare them.  He ran lawnmowers, generators, go carts, and cars.

By far the cleanest, most complete combusting, least problematic in every way was Zippo.  It’s pricey but beat Coleman hands down for clean burn and power without knocking.

Jim

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FYI, though some swear by Coleman, I found a series of pretty scientific shade tree tests of gas alternatives. This guy carbon cleaned engines before and after runs, used infrared thermometers, tach readings under load, even a see through head on a four stroke to compare them.  He ran lawnmowers, generators, go carts, and cars.

By far the cleanest, most complete combusting, least problematic in every way was Zippo.  It’s pricey but beat Coleman hands down for clean burn and power without knocking.

I've tried a few fuels so far and for me, I like Zippo so far the best. My two H&M engines just run better on it.
For how little they use, it doesn't work out that cost prohibitive. I drain the tank of any left overs back into a fuel holder and buying the Zippo cans in bulk off eBay is a pretty good way for me to purchase and cheaper than a tobacconists.
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Jim

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ShadetreeMotorcycle

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That's good enough for me!...I was leaning towards Zippo because I like the can it comes in....was just not sure if Coleman was cleaner as it is a cooking product....I have found 12oz cans of Zippo for as low as $6.99 for as little as these small models burn, that price is fine by me....I just want to run the best performing fuel.

    I was wondering if anyone has found a clever way to deal with exhaust fumes in the house?...I don't want to run it for hours at a time...but for several min in my spare room workshop....my first thought was to slide a rubber tube over the muffler and drop the other end in a pail of water....in hopes the bubbles rising thru water may purify the fumes some?....probably best to vent out a window?....I think the water method may make some unwanted back pressure....

Jim

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That's good enough for me!...I was leaning towards Zippo because I like the can it comes in....was just not sure if Coleman was cleaner as it is a cooking product....I have found 12oz cans of Zippo for as low as $6.99 for as little as these small models burn, that price is fine by me....I just want to run the best performing fuel.

   

I too like the Zippo cans, I was hoping that the squirter lid would act as sort of syringe to fill the tank as they are bloody finicky but it didn't work as hoped.

Quote
I was wondering if anyone has found a clever way to deal with exhaust fumes in the house?...I don't want to run it for hours at a time...but for several min in my spare room workshop....my first thought was to slide a rubber tube over the muffler and drop the other end in a pail of water....in hopes the bubbles rising thru water may purify the fumes some?....probably best to vent out a window?....I think the water method may make some unwanted back pressure....

For short runs with the window open, I reckon you'll be ok (I do it) I hate fumes and I haven't been bothered at all so far with these fun little engines.
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Cheers.
Jim

My YouTube Channel https://www.youtube.com/user/Blue123Heeler/videos