variated tomos a52

Ive never made a build thread before, but I've decided that this might be worthy of documenting since as far as i know the only other variated tomos engine powered moped was built by tomahawk tuning. The only info i can find on the tomahawk bike was a pic and a few sentences describing it. Im not super far along with the bike, but this is the what i have planned. Its going to be powered by a modified tomos a52 engine and ill be putting that into the 81 (le moped) i just snagged of of craigslist.

I was originally going to modify my batavus regency roller i have, but the moby is a much better choice for a chassis for a lot of reasons. Im planning on using as many off the shelf parts as i can and keep machining and welding down to a min. i dont have pics of all of the destruction, but i started out by taking most of the transmission components out of the engine. i split the cases pulled the crankshaft and drive axle and then started trimming the case halves down lol

i started by cutting the engine in half, after it was a more manageable size i used a drill press to make a series of holes around the crankcase to remove as much material as i could before i started carving it down with the dremel and a hss burr.

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i just spent 2 hours writing a build thread and only part of it showed up wtf!!!!!! im going to bed

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Re: variated tomos a52

Cool! Fun project!

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Trans-side case half sitting on top of the yet to be trimmed stator-side case half.

Here is the same piece viewed from the rigtht, you can see how rough the cut aluminum is.

Stator-side case half roughed in, ready to be finished off.

One of the challenges I had trimming the cases down was positioning them securely in a way that let me brace my hands, so that the hss burr wouldnt grab the aluminum and walk. I tried clamping them in a vise and using c-clamps, but the easiest way I found to hold them was to drill some holes in the plywood I was working on top of and bolt them down.

With the case halves bolted down, it was easy to get the crank case halves trimmed and file the remaining aluminum flush to the rest of the case.

I easily spent 20 hours to get the case halves looking good enough, Luckily I only made one mistake while trimming them down ( bottom pic ) with the drill press, I'll just tig that and file it back down:)

Early on in the project I was thinking of how I should go about variating the tomos engine. Should I go dual or single variated, should I use a motobecane front variator-clutch assy, or should I go with peugeot parts? I looked into maybe using a aftermarket variator, something like the doppler er3 with an aftermarket clutch pulley from doppler, or if you can afford it a mykitech clutch pulley and at the end of the day one could probably make any one of these ideas work with enough modification. After looking at all the different possibilities an idea popped into my head, why not use gy6 parts! I worked at a scooter repair shop for a couple years and the cvt side of a gy6 engine is burned into my memory from fixing drive belts on chinese crap all day long. I thought to myself a gy6 crankshaft is close in size to the trans side of the tomos crank maybe it would fit and In comparison to mopeds, scooter parts are for the most part much cheaper!

I yanked the koso variator off of my friend arons af16 swapped spree and threw it on the tomos crank, it fits!!!!! sweet!!!!

The tomos crank and the af16 both have a 14mm crank.

The 14mm dia section of the tomos crank is longer than the af16, so there is more than enough room to fit the ramp plate and boss before you hit the splined section of the crank. The only problem is that a tomos crank has a different number of splines compared to fixed sheave of the gy6 variator. one option to fix this would be to enlarge the splined center of the steel fixed sheave to 14mm, then make a 14mm id spacer to push the ramp plate, boss and fixed shaeve to the end of the 14mm dia section of the crank and weld the 1st gear clutch hub to the fixed sheave basically making the tomos clutch hub the new splines of the fixed sheave. confused? Ill post up some more pics later on and explain it better later on.

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I approve of this.

btw frenchy never build a variated tomos motor.

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oops your right, i thought it was tomahawk i guess its these guys https://poochabacane.wordpress.com/ i saw it a long time ago

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damn!

We'd tried to variate an a35 once, but derbi style with a GY6 clutch and vario in place of the transmission gears.

It actually fit up pretty well, the belt motion didnt line up well enough though, and the reduction ratios are off. it was more of a fun concept idea cuz we had the parts laying around and got bored. but one of the biggest issues it had that you might also encounter is lubrication of the trans side seal which is setup to be lubed by the transmission. without some sort of oiling vent or somethin it could be a problem. maybe not though.

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tomos lube both bearings with 2t oil... e50 does the trans lube on the bearing thing.

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ahha! sweet. I just know you'll burn out crankseals with a dry tranny on tomos but i suppose its more about the clutches overheating then (edited)

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when its all said and done, trans side will be getting a single lip 17x35x7 oil seal just like the stator side. gila+gy6 clutch=no mo problems;)

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I'm doing much the same thing over at www.mjmotors.tumblr.com

Lemmie know how you progress!

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Project Is still coming along, picked up a sr50 so I've been a little side tracked, the aprilia engine is going in my spree:) Gotta make a bracket for mounting the modified tomos engine on the moby frame, templates are made but I need to pick up some 1/8 cromo plate steel.

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Hanging it from a modified head can work too.

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My glob this year is intense!!! Between this thing and the other 3 or 4 uber builds going on id say 2015 is Year of the Home Brew.

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Nooooooooo! Revive revive!

I hate getting to the end of a build thread.

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https://www.mopedarmy.com/forums/read.php?7,3863917 You can pick up over here for more insane Franco-Slovenian action.

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Yet again, I am left unsatisfied...

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OK its been a few years.... Did this ever happen?

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I guess he never finished it. Bummer!

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todd amundson /

I heard tomahawk’s finishing it.

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