Moby Av10 Er3 tuning

Moped army, I'm having some issue finding information on how to fine tune my ER3. Its a full 50cc doppler build, Cylinder, crank, reeds, spring, 19mm phpg.

My issue is that unless I run just 1 of the smallest weights on either side of the Er3 it will try on engage my belt at idle. Now if I run just 1 on either side it takes off normal but i cannot get the cheek to close and the bike never variates.

What i would like is the thing to have really nice take off and low end without revving to the moon.

Moby.jpg

Re: Moby Av10 Er3 tuning

Doppler spring is probably too stiff for your set up, it is far too stiff for most.

Re: Moby Av10 Er3 tuning

Cristian Luna /

Yeah definitely the Doppler spring I ran that same exact set up with a stock spring

Re: Moby Av10 Er3 tuning

Cool, Thanks for the help guys i'll remove the doppler spring and see how it goes. why all those weighs if you only need ligther ones?

Re: Moby Av10 Er3 tuning

Anyone have a good source for variator tuning knowledge?

Re: Moby Av10 Er3 tuning

it's always going to grab the belt at idle, since there isn't anything holding the sheaves apart it's going to try to close when its spinning. as long as it isn't trying to move the bike it's fine.

with a heavier spring you will need heavier weights than if you had a light spring.

with a lighter stock spring you need lighter weights. this has the advantage of causing less drag on the belt. the downside is that the variator can close too quickly and drag the engine towards the pulley and the engine can bounce. also since there is less spring force when you slow down the variator wants to stay closed. that's why you use a launch lever, to hold the engine when you launch the bike and to push it back when you slow down/enter a corner

with a heavier spring you won't have these problems but you need heavier weights to counteract the spring.

you are not using enough weight. the bike in the picture has about 6.5 gram on each arm. with the doppler spring you need more than that. I only ever used the stock spring so I use more like 8 gram on each arm. so you need more for sure.

I made a spreadsheet a while back of all the weight combinations+screw weights in grains, there is a similar table in the wiki but it is way off, the weights are wrong, also there are actually 4 different size doppler weights, and it doesn't account for the screws.

Re: Moby Av10 Er3 tuning

i should also mention that i have a kickstart and a kick start er3

Re: Moby Av10 Er3 tuning

kevin Smellaflange /

if anyone is building a launch lever

please take pics step by step...

i'd be interested in that work up.

Re: Moby Av10 Er3 tuning

> Ross Derer Wrote:

> -------------------------------------------------------

> What i would like is the thing to have really nice take off and low end

> without revving to the moon.

> without revving to the moon.

> without revving to the moon.

> without revving to the moon.

> without revving to the moon.

lol wut?

Re: Moby Av10 Er3 tuning

Dirty30 Dillon /

You built the wrong bike if you were looking for low rpm grunt.

Re: Moby Av10 Er3 tuning

Jonathan Feldman /

> Dirty30 Dillon Wrote:

> -------------------------------------------------------

> You built the wrong bike if you were looking for low rpm grunt.

I didn't wanna say it.. but he said it for me.

Doppler 50 Moby is about as high revving as they come.. zero low end. Or in my experience that is. Absolutely dead untill maybe 8k.

That French 50 life... no torque but the rpms just keep goin n goin.

Re: Moby Av10 Er3 tuning

Variator tuning at WIKI ,Ross.

Re: Moby Av10 Er3 tuning

Any one have any experience with the Doppler yellow spring?

Re: Moby Av10 Er3 tuning

Its much more suited to everyday riding without a launch lever. I think the stock spring with the bracket shimmed out would be fine on your set up.

Re: Moby Av10 Er3 tuning

i have the stock spring but i cannot locate the little hook bracket, but as an alternate i have the doppler setup already so another spring isnt a big deal as long as its gonna help me get where i need to be

Re: Moby Av10 Er3 tuning

Could probably find the right size spring at ace hardware

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