Plug color help

I’d like to thank this forum which has been indispensable for the work I’ve been doing on a Vespa 50cc 2-stroke.

Here’s the configuration:

Malossi 70cc cylinder kit

Malossi (Dellorto) 19mm phbg carb

Stock airbox with 3 extra holes created per the Malossi carb instructions

Malossi red filter

Malossi variator kit and white clutch spring

Following guides found here I started with a 110 jet and have worked my way down to an 82 main jet. Throttle response is very good from idle, slight missing/bogging through the midrange, and very good from 75-100% WOT. Here is the plug chop I did with the 82 after about 4 miles of WOT. What does it look like to you? Thanks

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Re: Plug color help

which earl are you running in it?

Re: Plug color help

Probably Fred /

Ya that’s a scooter ! most people here won’t know the plug readings for that scooter,

This is a pedal Moped forum !

Search these https://mopedarmy.com/wiki/Scooter

Here is how you can tell the difference between a scooter and a moped

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Re: Plug color help

QUICK - before you get bombarded with anti-scooter remarks - check this plug reading guide. Run a fat jet until you get the rest of it right.

BasicPlugReading1.jpg

Re: Plug color help

I think it's lean and perhaps badly lean. So do yourself a huge favor repeat plug chop at 88 and 92 please post the chops. My 70 cc Athena with 21 phbg and two stage fiber performance thickness fiber Reed's , I think likes 98. So I'm just subtracting a few numbers. If u don't have a temp monitor on this baby ,which I assume is air-cooled and you are doing performance mods like this make sure whatever piaggio thought would keep the temps fine is updated.

Re: Plug color help

What did it do at w.o.t. with the 110?

Why did you go down to 82. What was happening to make that judgment call?

Re: Plug color help

Let me guess live evil at the events : as with all mopeders unless they are living moped gods it is hoped not expected that performance improvements will occur. So he is a bit rich and worries that he needs some performance. I'm sure it's running better with an 82 for a bit ..that is. Plus it's advanced. Yiiikes. Cruising for a bruising unless u r moped God. White at base is bad. So richen that up to point of some color. Ok now if u want to reduce excessive advance and find a degree that balances optimal timing of ok a Vespa so 16 degrees maybe but if u have curve even better. Then u can reduce jet number and match performance gain to color. Then do it for every 1/4 throttle position , experiment and note differences in needle size and position , idle jet , emulsion tube size , all this insanity awaits you. This should really kick ass dude. I want one. I want one thats a two stroke water cooler scoot , kick start. Ooooooh

Re: Plug color help

I just want to be sure hes not tuning for mid/low end because that needs to be done otherwise. Instead of assuming he knew how to tune a carb I asked a couple of questions. Really???

That is all (edited)

Re: Plug color help

@live evil ....totally agree !! That's why I urged first to tune at wot

Re: Plug color help

Scott Hargreaves /

> Overpriced Parts Wrote:

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

> Ya that’s a scooter ! most people here won’t know the plug readings for

> that scooter,

>

> This is a pedal Moped forum !

>

> Search these https://mopedarmy.com/wiki/Scooter

>

> Here is how you can tell the difference between a scooter and a moped

(edited)

Re: Plug color help

> Overpriced Parts Wrote:

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

> Ya that’s a scooter ! most people here won’t know the plug readings for

> that scooter,

>

> This is a pedal Moped forum !

>

> Search these https://mopedarmy.com/wiki/Scooter

>

> Here is how you can tell the difference between a scooter and a moped

In all seriousness, I enjoy trolling with my own sick sence of humour but when it comes down to it, scooters have out numbered mopeds for awhile now and are the here, now and future. Does not mean I like it. Its fucking reality. Wake up and accept it!

MopedLar is a good dude and owns and rides scooters. Ive met and done business with him in person. Do I look down my nose at him??? FUCK NO! Why would I?

Go ahead and be closed minded all you want but there are quality scooters and moped members with them.

Any way you cut it, its fucking discrimination.

Re: Plug color help

And yeah its a "moped site", but when you got every ass clown on the street plus half the DMV's calling scooters mopeds what the fuck do you expect to happen.?????? (edited)

Re: Plug color help

Traffic coming to our door step and we're gonna run them away by sending them to another site or the murky waters of "off-topic"? Its not their fualt they dont know the difference. So we educate them and direct them to an appropriate scooter forum. You dont have to go to that forum if you dont want to see or read it. Flame any scooter owner not following directions. They're being flamed anyways.

There's plenty of moped/scooter owners here to field questions in a scooter forum.

Thread jack over.

Re: Plug color help

Scott Hargreaves /

Re: Plug color help

Notice the original poster departed. So untill he reappears with the requested plug chops I say goodbye

Re: Plug color help

My first thought when I looked at your plug was that the plug's heat range was too cold. It's my understanding that a plug with only 4 miles of hard running should look a lot cleaner. These instructions advise you to get the plug heat range correct as a first step.

http://www.strappe.com/plugs.html

Re: Plug color help

Robert Horton /

Ok I’m back and thanks for the replies. New to this forum and was expecting to get emails when I got responses.

Ok so the consensus is it’s lean. I will richen it back up. A question was asked what’d I it do with the 110? It started and ran but it bogged pretty badly, which to me seemed like way too much jet. I stepped it down in increments of 2-3 sizes 108, 105, 102, 100, 98, 96, 94...all the way to where I am now. Runs well off idle and well at WOT but not in the middle. In the middle it’s not running smoothly. I see another poster commented that he hoped I wasn’t tuning for mid-range because that’s something different. Well that’s exactly what I need.

I will start again with the jets in the high 90’s and post the plug chops. In the meantime how do I finetune the midrange?

And thanks for the responses even though the bike is a scooter. I do know the difference but this site seemed to have the best knowledge of any others I found.

Re: Plug color help

When your carburetor mid-range tune with needle adjustment or different needles that have different tapers.

Re: Plug color help

First tune to Wot on plug color and temp and u should be just gurgling close to four stroking but getting into pipe. Then for mid-range start with lowering and raising needle. If unsuccessful in getting mid-range smothed out post your results.

Re: Plug color help

> Marc Friedman Wrote:

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

> First tune to Wot on plug color and temp and u should be just gurgling

> close to four stroking but getting into pipe. Then for mid-range start

> with lowering and raising needle. If unsuccessful in getting mid-range

> smothed out post your results.

Exactly^^

Re: Plug color help

But please note that if the intake duration is too short as in do you need a thicker base gasket because gas starvation will produce similar results with all sorts of jets because the cylinder doesn't have enough time. So make sure that on a performance kit to make sure the intakes are just clearing at bottom dead center. . I had to learn this lession. Super interesting. So that's another reason tonrrchecknsone things such as that and your squish, plus what pipe again exactly ?

Re: Plug color help

Robert Horton /

Thanks for the replies. The needle came stock in the very lowest setting, that is, the clip was in the highest ring. I raised the needle one position when I started. That in itself is a whole other beast as I had to take the bike apart to undo the cable at the top just to get enough slack to attach the far end to that slide piston in the carb.

The pipe is a Leo Vince touring that I ground the weld out of and removed the restrictor cone.

Re: Plug color help

Robert Horton /

And thanks for the additional replies. I’ve got new hope that I’ll get this thing tuned yet!!

Re: Plug color help

Picture of the Leo Vince please. The Leo Vince I was going to mod for my Hobbit mallosi watercooler really falls out of performance at a relatively low rpm. I just posted about that elsewhere a couple of weeks ago. The ones without the stinger.

Re: Plug color help

Robert Horton /

Ok. Finally made it back. Here is the latest plug chop. Changed the 82 that was in there out to a 92 and ran about 4 miles WOT. This is what I’ve got now

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Re: Plug color help

Robert Horton /

> Marc Friedman Wrote:

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

> Picture of the Leo Vince please. The Leo Vince I was going to mod for my

> Hobbit mallosi watercooler really falls out of performance at a

> relatively low rpm. I just posted about that elsewhere a couple of weeks

> ago. The ones without the stinger.

Here is the Leo Vince

B9CFBBC7-325A-48FE-8C8B-82427ADB08AE.jpeg

Re: Plug color help

Robert Horton /

> live ɘvil Wrote:

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

> What did it do at w.o.t. with the 110?

>

> Why did you go down to 82. What was happening to make that judgment

> call?

I started at 110 and went all the way down, 2-3 jet sizes at a time trying to get rid of what felt like bogging. It ran but ran terrible with the 110 and barely made 30mph. As I moved down jet sizes it became more responsive. Someone else commented that he hoped I wasn’t tuning for mid-range, which I was, and now I’m posting the requested plug chops to get feedback.

Oh. Someone else asked what oil I’m running. It’s Motul 2T 2-stroke motor oil direct injection that I have premixed into my gas at 25:1.

Re: Plug color help

So my speedy friend that Leo Vince pipe while so sexy and carressable may be your problem !! I see a bit of color at the base now so that's better. But these leo Vince pipes without a stinger will peak out at an early rpm. If you are looking for.performance up to way higher rpms u need a pipe with a separate stinger such as side bleed Leo Vince.

Re: Plug color help

Robert Horton /

awesome so if I’m reading your response correctly you’re saying this jet is better and I now need to focus elsewhere to find the perfect tune. Right now it idles great. Takes off very well but between ~25-75% throttle it’s a bit raggedy and then at wot it smooths out again and achieves 51-52mph on the speedo

Re: Plug color help

Perhaps u are at the correct jet. Keep going up until it is way way four stroking. Then go back down. Try a 96 is my suggestion.

The pipe may be the limiting factor on just how high the engine will rev. But low 50s sounds nice. I personally don't want to go faster. If u want to rev up to 12k it needs a different pipe I suspect. Try a temp gauge on the plug.

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