Re: Fastest 50cc moped

Matt Mahloch -- MBM Customs /

I think EFI could be very beneficial on a top speed application. Turning the carburetor to be perfect at all rpm ranges is very difficult if not impossible. Having a properly tune to air fuel ratio throughout the whole rpm range can be the difference of getting in the pipe or not.

Re: Fastest 50cc moped

> Chöschi21 C.K. Wrote:

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

> Well, thats true, but if you ever see a Moped on one of those Events, no

> matter what cc, it would be cool if you could post Pictures of it here.

I have some threads about moped racing in the Netherlands with pics of racing mopeds.

Thread 1 2015

Cant find the other one though.

Re: Fastest 50cc moped

you should check out these guys they are selling a cylinder that looks and claims to be one of the highest hp 50cc puch cylinders. For now they only have the case inducted versions, but they are supposed to make a cylinder inducted version later. https://www.facebook.com/pg/ToroRacingDivision/posts/?ref=page_internal

Re: Fastest 50cc moped

Chöschi21 C.K. /

I showed this thread a couple of Guys from my Class and they all said thats slow for a 50ccm with these mods, i had to explain to them that you only have a Mile to get to those speeds with only one Gear...

Re: Fastest 50cc moped

Dirty30 Dillon /

> Chöschi21 C.K. Wrote:

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

> I showed this thread a couple of Guys from my Class and they all said

> thats slow for a 50ccm with these mods, i had to explain to them that

> you only have a Mile to get to those speeds with only one Gear...

Damn, Swiss high-schooler's are straight throwing shade.

Re: Fastest 50cc moped

That video of the carb foaming is brilliant, once the fuel begins to cavitate it no longer supports the weight of the float allowing unmetered fuel to flow past the valve hence the flooding.

Re: Fastest 50cc moped

Chöschi21 C.K. /

We don't have High-School here, 6 Years Primary, 3 Years Secondary, after that you have endless options, i chose a 4 Year Apprenticenship as a Truck Mechanic for wich i go to School one Day a Week and learn about all kinds of stuff for that job, Taxes, Politics and other stuff.

Re: Fastest 50cc moped

timothy rendall /

Apprenticeships are the best thing :)

Re: Fastest 50cc moped

Socialism rules

Re: Fastest 50cc moped

> Chöschi21 C.K. Wrote:

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

> We don't have High-School here, 6 Years Primary, 3 Years Secondary,

> after that you have endless options, i chose a 4 Year Apprenticenship as

> a Truck Mechanic for wich i go to School one Day a Week and learn about

> all kinds of stuff for that job, Taxes, Politics and other stuff.

that sounds really sensible. Good thing I went to all those years of calc and trig that I've literally never used.

Re: Fastest 50cc moped

Hey Douglas, I really wanted to respond (though I know I’m like a month and a half late).

You should totally look into the EFI stuff. it doesn’t take 2 years to figure out, it’s not too difficult. The benefits are all there, it’s really quick to tune if everything’s stable. The resolution of your fuel system is absolutely amazing. It requires much more wiring & some grounding considerations, but it’s way fun & really satisfying when it works.

In terms of reliability: My maxi had two mopedGP showings, one had a fuel system problem & a wreck, the second time had nothing to do with the EFI (in fact the EFI saved me a ton of time at the track).

If you’re at WOT, the only benefit is a throttle body which is less constrictive than any carb will be able to supply (don’t have to meter on vacuum anymore). Other than that, the only real benefit would be live control of a fuel factor using a pot on the bars to adjust.

The lowest hanging fruit –in terms of power- isn’t the fuel table, but the ignition table. Applying advance per RPM AND throttle angle is the big payoff (especially if your porting is violent). Lots to talk about there, but you probably wouldn’t care for a land speed bike because you’re not working with partial throttle angles.

This is a really good thread & lots of fun to read. Also Daniel’s a dick, so always factor that in ;-)

Re: Fastest 50cc moped

Chöschi21 C.K. /

I would like to know how you are planning on monitoring the AF/R, are you going to try getting it with the Exhaust gasses, or are you going to try getting the AF/R right with monitoring the amount that gets into the engine?

Re: Fastest 50cc moped

Douglas Binder /

The bike has a wide band afr gauge. I leave the O2 sensor out unless I want to take a reading.

Re: Fastest 50cc moped

Chöschi21 C.K. /

Just a small question: where can i Read the Rules/Restriction foe the Class you race in?

Re: Fastest 50cc moped

Douglas Binder /

It depends on where you race. Start with SCTA. They race at Bonneville.

Re: Fastest 50cc moped

Mikey Antonakakis /

> Alex Degnes Wrote:

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

> What happened? Why isn't this common stuff nowadays?

Who says it isn't? ;)

Re: Fastest 50cc moped

Mikey Antonakakis /

> Time Warner Wrote:

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

> The lowest hanging fruit –in terms of power- isn’t the fuel table, but

> the ignition table. Applying advance per RPM AND throttle angle is the

> big payoff (especially if your porting is violent). Lots to talk about

> there, but you probably wouldn’t care for a land speed bike because

> you’re not working with partial throttle angles.

Kicking myself for losing this thread over the last year. Haven't run EFI on a moped, but yeah, it's funny reading sites like kiwibiker where guys that have spent their whole lives getting 400hp/L (and more) with carbs and fixed or RPM-only dependent timing are wrapping their heads around EFI. Of course there are some specific challenges presented by high-strung 2-strokes (e.g. the pipe will behave vastly different depending on EGT, which isn't a common input for adjusting tuning on the fly in EFI systems). But the great part is, once it's installed, it is outrageously quicker to make tuning changes. It's towards the top of my list of projects to try.

In any case, since Doug is taking a break from LSR, and I'm building a pretty powerful single-speed 50cc right now, and Alex is heading to Bonneville (with CVT 50cc) I've been seriously thinking about using that bike for the purpose. And.or maybe for mini-moto racing (going to check out a local race in a couple weeks). The bike is currently getting wired up for EGT and O2 sensor, along with the rest of its wiring.

Re: Fastest 50cc moped

Douglas Binder /

Mikey, I'm still watching this thread. If you want to dabble in EFI, I ended up an Arduino based system with dual injectors. I got it basically running before focusing on the cylinder so contact me if you want any help going that route. In the mean time, my Kitfox airplane is coming along nicely. :-)

Re: Fastest 50cc moped

oh shit!!! post the plane we wanna see it. please.

Re: Fastest 50cc moped

Douglas Binder /
IMG_20190506_201501233.jpg

I told UHaul that I was trailering a Honda Fit... The plane will be completely stripped down and rebuilt. Stronger, faster, you know the drill.

Re: Fastest 50cc moped

Mikey Antonakakis /

So cool! I had the chance to fly in a Thorpe recently, tiny little thing. It was so much fun. Will keep in touch re:EFI. Should hopefully finish the initial wiring of the bike soon, so I can do some more shakedown running and tuning. Build thread will get started soon too.

« Go to Topic — end of thread

Want to reply to this thread?

We'd love to have you join the discussion, but first you'll need to login (or create an account).