HPI mini on ZA50 - adding weight

Big Al's Moped Shop /

What have you done to add weight to your HPI mini rotor? I understand that ZA's dont like it light... Please and thank you!

Re: HPI mini on ZA50 - adding weight

I would use a flywheel weight like they make for dirtbikes. I would think hpi makes one.

Re: HPI mini on ZA50 - adding weight

ps. I have one on my za Gila and I love it with my slippy 1st gear clutch, but sometimes it stalls.

will a heavier flywheel keep it from stalling as easy? Yes.

Re: HPI mini on ZA50 - adding weight

Stalls at idle? You can try raising the idle speed as long as your clutch doesn't start engaging. I'm sure a weight could be fabricated, although it seems counter intuitive to get the lowest weight ignition and then add weight to make it heavier.

Re: HPI mini on ZA50 - adding weight

Matt Mahloch -- MBM Customs /

Heavy weight snap za cranks

Re: HPI mini on ZA50 - adding weight

Dirty30 Dillon /

Yeah but super light fucks the crank just as bad

Re: HPI mini on ZA50 - adding weight

Matt Mahloch -- MBM Customs /

Never had a light one snap, mini might not idle so a plate could be a good idea just to get it to idle. Standard HPI seems to be nice, it idles once warmed up with a Gila, won't cold though.

Re: HPI mini on ZA50 - adding weight

Big Al's Moped Shop /

Yeah, I'm not exactly sure what the deal is. I figured it might be hard on clutches or a balance issue. I'd like to bring the weight up close to a stock rotor and maybe tune down from there?...Idk Puchshop sells this 350 gram weight. Is this HPI's solution for za?

http://www.puchshop.de/catalog/hpi-verschwerungsplatte-p-847.html

Re: HPI mini on ZA50 - adding weight

Probably Fred /

Harsky & Sutch MMP Wrote:

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> Yeah, I'm not exactly sure what the deal is. I

> figured it might be hard on clutches or a balance

> issue. I'd like to bring the weight up close to a

> stock rotor and maybe tune down from there?...Idk

> Puchshop sells this 350 gram weight. Is this HPI's

> solution for za?

> http://www.puchshop.de/catalog/hpi-verschwerungspl

> atte-p-847.html

Ya I'm pretty sure that will work

If it does let us know

Re: HPI mini on ZA50 - adding weight

why did you buy a mini rotor in the first place if your going to be adding weight to it? should have got the powerdynamo or however you spell it....

Re: HPI mini on ZA50 - adding weight

Probably Fred /

Tommy "buttcheeks" BUZZARD Wrote:

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> why did you buy a mini rotor in the first place if

> your going to be adding weight to it? should have

> got the powerdynamo or however you spell it....

Power dynamo don't have a kit saving ignition curve like Hpi does

It's flat/static timing curve like points.

It's hard to keep temps down on a kitted bike specially with the big pipe/low gear hi rpm setup without a curve (self retarding) ignition.

Re: HPI mini on ZA50 - adding weight

The HPI would have trouble idling at low speed or when cold because of the reduced inertia that the flywheel provides to "coast" the crank on to the next power stroke. With little to no rotating mass the compression forces can stall the rotation and kill the engine.

As for damaging the crank that could be simply due to the speed at which it can accelerate through the rpm range before the clutches begin to grab or before they are fully engaged. Imagine throwing an automatic transmission into drive after revving it up quite high, You are likely to break components that are meant to endure a more gradual engagement with less shock load. The clutches are likely to slip at a higher rpm as well before they catch. It all equals out to more abuse and wear.

Re: HPI mini on ZA50 - adding weight

i didn't know people were snapping ZA cranks? thats a new one.

the extra mass on the crank will make the 2 speed shift better, smoother, and carry a little torque into the next gear. so thats a good thing.

sounds like a good plan to me!

Re: HPI mini on ZA50 - adding weight

Big Al's Moped Shop /

I appreciate everyone's input! I like the HPI mini for so many reasons... the timing curve, it will fit alot of other motors, rugged, easy to set and reset timing, and will probably outlast the build. On my set up za bored large metra tm24.. well I don't want to destroy it in one season. Has anyone here done business puchshop maybe through Angelo? At 36 euro for the HPI weight, I think it's still cheaper than paying a machine shop to build one.

Re: HPI mini on ZA50 - adding weight

Not likely. I had an entire steering stem machined (multiple different diameters including a full length taper) for 100 bucks from steel. It should be less to machine a simple weight and drill some mounting holes.

Re: HPI mini on ZA50 - adding weight

Big Al's Moped Shop /

So dug a little further on this project. I decided to weigh some rotors I had laying around to get a an idea of how heavy a weight I wanted.

The HPI mini rotor weighs 335g

treats cdi za rotor 904g

stock e50 rotor 875g

I'm thinking 350-450g would be a good place to start.

Yikes... the first machine shop wanted 250.00. I'm def going to shop around.

Re: HPI mini on ZA50 - adding weight

if your only adding 50 grams just throw some bolts with nuts under them in the magneto.

Re: HPI mini on ZA50 - adding weight

Big Al's Moped Shop /

maybe I was a little miss leading... I'm looking to add 350-450g, for a total weight of just under what a stock rotor would weigh.

Re: HPI mini on ZA50 - adding weight

I'm surprised noone has mentioned the fan mounts that treats sells.

Re: HPI mini on ZA50 - adding weight

Big Al's Moped Shop /

I went down that road and bought one. It weighs in at 60g.. far from what I was looking for, although it could be used as an adapter to mount weight to.

Ideally I think a one piece weight would be best, especially at rpm.

Re: HPI mini on ZA50 - adding weight

Dirty30 Dillon /

I don't think that will be really that bad, especially if you just loc-tite the snot out of it.

Re: HPI mini on ZA50 - adding weight

Re: HPI mini on ZA50 - adding weight

Big Al's Moped Shop /

Hey Kevin.. Glad you are following this. Please post your results! I ordered one last night. Shortly after starting this thread I contacted HPI asking if part# 068v101 would work with mini rotor and Willy said no it was for the inner rotor. He gave me part#210v101 which isn't in the catalog and was made for mini rotor. I contacted treats asking if could special order. Benji was quick to get back with me and said he'd put it on the next stock order.. Bah da Bing there they are!!! It's only been like a week and a half. Gotta love Treats!!

Re: HPI mini on ZA50 - adding weight

MOPEDS HAVE GONE TOO FAR.

Re: HPI mini on ZA50 - adding weight

not a Baron Asshole /

you will def be smoother, but i dont like the acceleration loss, if its a daily driver i dont know why you didnt stick to points.

Pete

Re: HPI mini on ZA50 - adding weight

Probably Fred /

Baron Von Asshole Wrote:

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> you will def be smoother, but i dont like the

> acceleration loss, if its a daily driver i dont

> know why you didnt stick to points.

>

> Pete

Because points ignition don't retard

Air cooled puch kits run hot without retarding type ignitions especially with big hi rpm pipes, big carbs and lower gears.

Re: HPI mini on ZA50 - adding weight

You CAN run points on larger setups with aggressive pipes AND successfully manage temps on a 70cc puch.

I can't speak for anything larger than that but I've been running points and a mini rotor on 2 70cc weekends puch reed kits MLM pipe hi comp head.

I also have 2 TCCD 70 CC kits with MLM and treats pipe one with points again never a temp issue if it's all setup right which isn't difficult on a puch E50.

Re: HPI mini on ZA50 - adding weight

NB0tt aholetechbro /

So what's the update on this? Did you add the weight? Did it help with idle?

Re: HPI mini on ZA50 - adding weight

Probably Fred /

brian schulz Wrote:

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> You CAN run points on larger setups with

> aggressive pipes AND successfully manage temps on

> a 70cc puch.

> I can't speak for anything larger than that but

> I've been running points and a mini rotor on 2

> 70cc weekends puch reed kits MLM pipe hi comp

> head.

> I also have 2 TCCD 70 CC kits with MLM and treats

> pipe one with points again never a temp issue if

> it's all setup right which isn't difficult on a

> puch E50.

Run a Gila or polini with a big pipe/hi rpm set up with points, hold wide open for 2 miles and see cool she runs. Small kits, treats reed kit and mild setups do ok with points. Love treats reed kit it runs cool/hard to seize

Big hi powered stuffs Hpi or retard ignition is the way to go

Hpi gives more spark/more power but man cost a lot .

Re: HPI mini on ZA50 - adding weight

Big Al's Moped Shop /

I’m glad this has been on someone else’s mind. I just pulled the bike out of the basement and into the garage last week. So Excited!! It took forever getting the bodywork right on one of those repop magnum tanks. I'll never buy another one of those things again, uggg so much work.. I only have about 10 minutes of run time on the motor… But Ken's right, I put HPI on this motor to keep temps down. Its an overbored large port metra 80 with MM Destroyer. My gearing is also limited right now with those 3 stars 20/37. The limitation of speed will drive me nuts especially after watching Rodney's experiment.

I set the timing a little conservative at 1.8 BTC, used a 10 idle and 160 main on a TM24.. It was a little fussy on initial start up and didnt want to idle. I switched to a 12.5 idle and it idles well. Ill test a 15. With the weight mounted it's still 300 grams lighter than stock. I was going to go on the maiden voyage today after work but the dumb arctic funnel is still here:( but yeah I wanted to thank TREATS and HPI. This rotor weight was under 50$ made of stainless, and fit perfectly...and thanks Ken for the tank mount! I'll report back when I can do some testing with and without the weight.

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