Puch Free Spirit Build [Polini RV4, Tomar Dry Clutch, etc.]

Background: So back in 2014 I purchased a 1979 Sears Free Spirit with the intentions of making something. After I tooled around the neighborhood for about 3 weeks stock - I got to work. The original bike was a mess, so I did not feel bad about its modification.

I always wanted to put up some pictures on Moped Army because when I started, I pretty much knew nothing about 2-strokes. I read the MA wiki’s, posts and everything else I could find for months… Anyway, I pulled some of the pictures off my phone and figured I would post them. This was my first moped and first and only build (if thats what you call it).

Modifications:

Treat Kit 70cc w/ Drilled Bing 15mm, Tomar Dry Clutch (td43) conversion with internal straight cut gears and kickstart conversion (first engine attempt)

Change to Polini RV4 water cooled, radiator, flatside tm24 with kart airbox, etc. (second and final engine attempt)

HPI Mini Rotor (The only thing I could find that would fit after I milled the area for the dry clutch)

LED Headlight converted into CEV housing with Morimoto Lens

Mike Thomas 5 star hub conversion

Trail Tech Vapor, with temp sensor, rpm

Suzuki K10 Forks with stiff springs, Brembo Caliper, Ducati brake lever

Yamaha FS1 Tank (welded front seams)

Custom Aluminum Rear Tail with Treats double brake light

Top tank Conversion with welded and supported swingarm, moved shock brace back 5 inches, frame extended about 5 inches.

Milled rear sprocket carrier to hold kart split gears

Modified BK100 exhaust to fit into RV4 head with custom muffler

YSS rear shocks

I am still trying to find my notebook with all my notes, pics, jetting, gearing, etc.

Still looking for my pedals… right now I have a bar. This moped has been sitting since late 2017, just got it back on the road over the weekend after installing a new chain tensioner.

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Re: Puch Free Spirit Build [Polini RV4, Tomar Dry Clutch, etc.]

Treat Kit 70cc w/ Drilled Bing 15mm, Tomar Dry Clutch (td43) conversion with internal straight cut gears and kickstart conversion (first engine attempt)

So after messing around with the stock puch e50 clutch, I decided I wanted to try a nice super "easy to adjust" external dry clutch. I went with the TD43 because at the time there was a .75” bore that would work well with a custom counter shaft. Below are the pics from the custom straight cut gears, after it was machined, custom shaft, and crank shaft parts.

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Re: Puch Free Spirit Build [Polini RV4, Tomar Dry Clutch, etc.]

Where is the pic? This must be the before pic? Got an after?

Re: Puch Free Spirit Build [Polini RV4, Tomar Dry Clutch, etc.]

After garage hardening, welded crank gear..

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Re: Puch Free Spirit Build [Polini RV4, Tomar Dry Clutch, etc.]

70cc first attempt

Crank and gears...

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Re: Puch Free Spirit Build [Polini RV4, Tomar Dry Clutch, etc.]

More pics..

Kickstart donor..

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Re: Puch Free Spirit Build [Polini RV4, Tomar Dry Clutch, etc.]

Final Engine (70cc)...

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Re: Puch Free Spirit Build [Polini RV4, Tomar Dry Clutch, etc.]

more engine..

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Re: Puch Free Spirit Build [Polini RV4, Tomar Dry Clutch, etc.]

Frame welds, etc.

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Re: Puch Free Spirit Build [Polini RV4, Tomar Dry Clutch, etc.]

Bike Shell..

Rear cowl/Pan.. (edited)

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Re: Puch Free Spirit Build [Polini RV4, Tomar Dry Clutch, etc.]

Milling rear sprocket carrier, mounted..

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Re: Puch Free Spirit Build [Polini RV4, Tomar Dry Clutch, etc.]

Headlight, projector and led...

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Re: Puch Free Spirit Build [Polini RV4, Tomar Dry Clutch, etc.]

Rear turn assembly and bracket from aluminum..

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Re: Puch Free Spirit Build [Polini RV4, Tomar Dry Clutch, etc.]

Change to Polini RV4 water cooled head (second and final engine attempt)

Milling some more "space"..

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Re: Puch Free Spirit Build [Polini RV4, Tomar Dry Clutch, etc.]

RV4/e50 complete...

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Re: Puch Free Spirit Build [Polini RV4, Tomar Dry Clutch, etc.]

more engine, etc...

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Re: Puch Free Spirit Build [Polini RV4, Tomar Dry Clutch, etc.]

Mikuni TM24 flatside intake parts and final...

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Re: Puch Free Spirit Build [Polini RV4, Tomar Dry Clutch, etc.]

I need to take some pics of the ped today... will update with more pics in a bit.

Thanks

Re: Puch Free Spirit Build [Polini RV4, Tomar Dry Clutch, etc.]

Looks rad!

Re: Puch Free Spirit Build [Polini RV4, Tomar Dry Clutch, etc.]

Let's see more of that drive chain tensioner dealie back there

Re: Puch Free Spirit Build [Polini RV4, Tomar Dry Clutch, etc.]

This is so gnarly. I want to see more!

Re: Puch Free Spirit Build [Polini RV4, Tomar Dry Clutch, etc.]

Ok, so I can't find my original pedal cranks, I don't even remember where I purchased them. They were machined aluminum arms, anyway here are some more pics from today. As you can see, I need to finish my seat with a cover and find some pedals so I can still get home.. Also, I have a cover/cage I made for the mini rotor and clutch, which is also missing.

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Re: Puch Free Spirit Build [Polini RV4, Tomar Dry Clutch, etc.]

...

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Re: Puch Free Spirit Build [Polini RV4, Tomar Dry Clutch, etc.]

..

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Re: Puch Free Spirit Build [Polini RV4, Tomar Dry Clutch, etc.]

New chain tensioner near the rear sprocket, its just the cheap motoX unit that is everywhere, but work as it should. Up front is a delrin guide for the clutch sprocket.

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Re: Puch Free Spirit Build [Polini RV4, Tomar Dry Clutch, etc.]

What gear oil do you run in the cases?

Re: Puch Free Spirit Build [Polini RV4, Tomar Dry Clutch, etc.]

hmmm, its been so long, I believe it is Redline MT-90 Gear Oil, at the time whatever I had on the shelf. I remember experimenting with the first 70cc kit, but not too much on the polini change.

Re: Puch Free Spirit Build [Polini RV4, Tomar Dry Clutch, etc.]

First and only build?

Re: Puch Free Spirit Build [Polini RV4, Tomar Dry Clutch, etc.]

Absolutely beautiful work.

Couldn’t possibly have learned that stuff from searching MA. People are searching this site for years and can’t figure out how to change light bulbs and get spark.

Re: Puch Free Spirit Build [Polini RV4, Tomar Dry Clutch, etc.]

I’m surprised that the final output shaft turns fast enough to engage a clutch.

I’m too lazy to do the math before posting this.

But what is the rpm to engage that clutch?

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