77 Peugeot 103 upgrading/performance

Sal RVA mopeds LLC /

Just picked up this fresh ass 103 the other week and im tryna make this a 50/50 up in the future. just trying to make small upgrades here and there until i get the scratch to split the cases and pop in a worthy crank and a well deserved beastly 50cc kit. I have experience with variated bikes from tuning and working with my hobbit so im not a noob in these aspects of bikes. just basically wondering whats bang for the buck in frenchy land so i can accomplish this along the way. As far as i understand if i run a clutched variator which is what i plan on doing my pully options are like 3 diff ones unclutched. but the pulley doesnt have a performance effect correct? Im immediately upgrading to the malossi and sha 16mm option with polini reeds. is it crazy to think i can get 50 out of the stock variator? i heard dropping 3 ball weights, upgrading reeds, intake, and carb and derestricting this stock pipe will get me to 40 on my stock cylinder... crazy but is that true? im deff willing to upgrade this between er2, er3, polini, or that rando cheap shit that was on treats but whats the performance gains/flaws of these variators im looking at? port work... not a stranger to it so whose got tha clues on the good grinds to my stock cylinder? also, pipe options for the threaded stock cylinder until my upgrade. should i just derestrict the stock cuz i havent found aftermarket one made for threaded cylinders. unless i choose to hack and weld some shit but thats lame... id rather wait and get the pipe when the cylinders upgraded. all input, advice, and experience is appreciated, thanks guys!

Re: 77 Peugeot 103 upgrading/performance

Downhill Harvey (OFMC) /

I'm doing 40 with just a pipe, a 15 SHA, and mild porting. Stock intake, reeds, and vario.



Re: 77 Peugeot 103 upgrading/performance

Sal RVA mopeds LLC /

What all did your port work consist of, just raising the exhaust and polishing the transfers? Are there many threaded cylinder aftermarket exhaust pipes still in production?

Re: 77 Peugeot 103 upgrading/performance

I've had this one going 43...downhill...

stock cylinder

mallossi intake and reeds


top one pipe

3 balls in the vario w/ lightened arms

exhaust lip on the bottom of the port filed off

milled head

i'm putting an airsal 50cc kit on it (case match) and the mbk cdi...actually kinda scared that it will hit 50...lol

Re: 77 Peugeot 103 upgrading/performance

'stock peugeot 103 tuning' thread

its like 10+ pages of awesome... search it

Re: 77 Peugeot 103 upgrading/performance

Sal RVA mopeds LLC /

@matt same 103 as mine, just as clean too! Thanks grahm I'll search and study!

Re: 77 Peugeot 103 upgrading/performance

What is a good exhaust for the stock cylinder?

Re: 77 Peugeot 103 upgrading/performance

there aren't a lot of options for the screw in type exhaust but there are a few...

treats has a few ranging from cheap stock knock-offs to mlm side-bleed pipes to what a lot of folks use which is the simonini circuit...

most of them use an adapter that slides into the pipe and then screws into the cylinder

Re: 77 Peugeot 103 upgrading/performance

Christophe Naulet /

I got 40 mph on flat with a complete 100$ stock 103, just 2mm exhaust porting.

In my opinion keep your peugeot stock right now, I mean do some research to get the best out of it with mild porting, variator 3 balls, etc.. without spending a dime, especially not in a malossi reed block.. and save your money for when you're ready to do the real upgrade for 50+ mph top speed.

When your ready with the right budget do this:

Spend the money where it counts

Get an er3 variator the best for peugeot, the variator is EVERYTHING on those french bikes

dont be cheap and dont get the er2 you'll regret not buying the er3


locticte the guide threads, grease all the moving parts, maybe add a shim inside so the belt seat almost all the way down to regain a little low end

get the malossi belt little wider and little more range than the doppler belt

(moby get the doppler belt)

keep ur stock clutch system

might need a 2nd clutch trust washer with 70cc kit that runs hotter and makes the clutch sticks at idle sometimes

keep ur stock crank

keep ur stock cases

Get a gila 70cc kits for easy case port match (dont port the kit)

(it's hard to make a peugeot 50cc rip, 70cc rips out of the box but keep it low rev, reliable, you'll be happier with the torque than with a 50cc kit, moby 50cc kits are toruqy and rips because of the ports and different stroke

get a malossi reed block

get a 17 or 19mm carb (clamp style cause not much room with sub frame, 15 or 16 will run if you worry about gas mileage but won't be as powerful

cut some of the sub frame to create room for ur carb and filter, dont be afraid it won't break

get a good high comp no decompressor head 70cc like polini and plug both decopmp holes the big and the tiny one.

peugeot head gasket always leaks there no matter what when is gets hot especially with 70cc kits, air always gets suck out.

also tap and plug the decomp hole in the cylinder with 1/4" allen socket screw, should be tight and bottom out almost all the way down to the exhaust port wall

use a malossi 70cc aluminum gasket + rtv red silicone on both side

(always check for leaks though with peugeot kits hot due to small air fins, and re-tighten the head if needed or change the gasket)

get a motobecane stock cdi at treats (easy conversion for peugeot, may need 2 spacers between the stator plate and grind 3 spots to clear the cases bolts) dont get the gold tapper stock cdi version from 77mopeds the trigger mark to set the timing is off.

there's NO perfect spring on the market = cheap, right tension and good quality

lose ur stock spring and get a doppler spring, little expensive but better quality than polini aluminum mounts that breaks or falls off and spring too soft needs to be combined with stock one.

find a way to replace the ball joint type nut that tends to come off the bracket making the spring lose and potentially losing it when riding or removing the belt, with a rod end ball joint + screw through the sub frame, much safer.

doppler spring a little too strong sometimes for low revving engines that needs all stack of weights on the variator to be tuned for take off and top end. If you struggle tuning it you can always go to a spring store and replace the strong red doppler spring with softer smaller gauge one.

pipe I would say doppler for good all around power and top speed but u'll lose the pedals

if you have the money get the new polini pipe good mid top end, should clear the pedals

less budget get the simo circuit pipe low mid range but it often cracks with peugeot vibrations, gotta be rubber mounted but sill no guaranty to last

I think that's it.

you'll be very happy with that set up with 50 mph guarantied that should be reliable, but I don't know lots of fast peugeots reliable blasting everyday :)

there's always some little things going wrong that you gotta keep an eye on, lose pipe ball joint if you didn't secure it with extra bracket, cracked pipe, lose baffle, clutch disc broken (especially after market ones china), head air leaks, I guess common stuff on kitted mopeds in general but more on peugeot because of the vibrations (no rubber bushings), swing engine, and super tiny cylinder fins.

Re: 77 Peugeot 103 upgrading/performance

This one makes it up to 102 kph on a long flat GPS timed if you get out of the wind and will pull 60ish up moderate slopes with the 11/34 gearing. Christophes post is bang on the money imo. A 10% mix of high octane seems to help with my timing/altitude. The 70cc Gllardoni kit if lovely no question and it seems to work well with the stock cases altho this has a 3rd transfer opened up. 17mm mikuni carb is a real blessing after faffing about with dellorto phbg jetting..I made my own gasket out of 0.2mm (i think) copper shim and it seems ok if you re-anneal it now and again. Using the gianelli pipe lets the pedals stay on altho not the centre stand. It puts a smile on my dial every time.


Re: 77 Peugeot 103 upgrading/performance

Christophe Naulet /

nice bike.

100+ kmh is really good.

yea can't have both pedals an kick stand with the straight performance pipes doppler, giannelli, etc..

Re: 77 Peugeot 103 upgrading/performance

One of the best most informative threads ever! Tomahawk!

Re: 77 Peugeot 103 upgrading/performance

Man I love it when Christophe comes thru and drops some pug knowledge!

Love that guy!

This is my lady, took her out for a ride 2 days ago when I took this flick and finally killed the shocks, can't wait for the new ones to get here.

Untitled by atlsmokin, on Flickr

Re: 77 Peugeot 103 upgrading/performance

Sal RVA mopeds LLC /

for right now; installed polini reeds, malossi intake, 15.15 sha, uni foam filter, still gotta dremel out the lip in the exhaust port and take 3 balls out the variator. i derestricted the pipe and this was the only thing that easily came out. is that all thast to it? ill post again with jetting and performance gains as a follow up.


Re: 77 Peugeot 103 upgrading/performance

yep, that's it...

read up on cheetahchrome's variator disassembly before you dig into the vario...it's invaluable.


Re: 77 Peugeot 103 upgrading/performance

did you loctite those reed screws and loctite all the reed block hardware?

and everything else. peugeots are notorious for shaking themselves apart, especially the intake.

clean the threads of the exhaust really, really good - get all the black and grease out- and install a new exhaust gasket (this is critical)

don't forget to go back and tighten that nut after every ride until it stops tightening. usually this takes 3-4 rides and retightenings.

Re: 77 Peugeot 103 upgrading/performance

#CrazyWayne™ rocks. #CrazyWayne /

Graham Motzing Wrote:


> did you loctite those reed screws and loctite all

> the reed block hardware?


> and everything else. peugeots are notorious for

> shaking themselves apart, especially the intake.


> clean the threads of the exhaust really, really

> good - get all the black and grease out- and

> install a new exhaust gasket (this is critical)


> don't forget to go back and tighten that nut after

> every ride until it stops tightening. usually this

> takes 3-4 rides and retightenings.

Then tack/tag weld the nut to the header.

Re: 77 Peugeot 103 upgrading/performance

Sal RVA mopeds LLC /

Figured I'd give this post an update so you guys see the route I'm going and can use it for comparison... chime in, share your thoughts!

First thing I did immediately was swap out that janky Gurtner carb and restrictive reeds for the Malossi 15mm intake and 15.15. SHA. Using high flow red UNI filter just to keep the sand and bs outta my carb. 68 main jet right now. Since Peugeot has the same reed pattern I decided to use some Puch Polini 2 petals I had sitn in the drawer. Forgot to locktight everything so I will be taking this apart and going back over it when i remove the top end and frame. Thanks for the reminder Graham!

De-restricted the stock exhaust which took me all of 3 min. lol

Bought a new toothed belt from Napa (under $15) AX32

Took 3 balls out of my variator

Installed a new shiny 3 blade pulley (need to replace the inner bearing once i kick the rpms up

Also double stacked the thrust spring washer as recommended by local TSM rider, Robert Barrow. This increased my launced significantly, especially with dropping some variator balls!

The original clutch pad looked real brittle and was cracked in some spots so I replaced that with one from treats. Choosing which one was a debate considering some of the reviews were bad on sizing and quality. I chanced it and went with this one.


"Aftermarket", more holes to dissipate heat better? whatever, it fit snug in there, doesn't rattle around, does its job... exactly what I was looking for! I recommend this as a replacement!

With these modifications Ive managed to get about 33/34mph on the top end with no port work!

Thinking my bike was too fresh to worry about the 2 coil ignition (less than 900mi)... chea right haha! This past week the condenser has weakened/gone out causing my points to arc hard after riding about 5 mi resulting in overall bad performance sometimes leaving me laughed at on the side of the road til it cools down. But that's okay... I got pedals on ma shit;)

Bought a puller, new condenser, timing micrometer, feeler gauge, and points! Gunna be replacing that this week when it comes in and hard wire my bike using the diagram on the wiki. If the coil starts shitting after i replace these parts, Ive been reading Grahams post about rewinding your coil here


Doesn't seem difficult, or i will replace with the internal Puch ignition.

Very good info on this site for Peugeot fix its!

The kit I decided to go with


Chose because its a budget buy, 50cc, 8ports, 3rd transfer... could be a sleeper! Came pre-chamfered but I like to be sure about shit so I went over it again. Looks good, I'll update with the performance after. Pairing it with that cheapo 77 circuit pipe til I get my feet more wet in this game. *using high tack on everythinggggg*

Gunna be running on the original seals and bearings until I get signs of wear. Bought some replacements and Hondabond for when that time comes> Jason BLKBLK;)

This week I'll be locktighting everything, case match and cut 3rd transfer into the case for the Giraudo kit, install my pipe, fix electrics and break-in/tune hopefully in time for LGN/Miss23 Rally wknd! Updates to come!

Question> Should I lap my crank since my RPMS are higher than norm? Timing hasn't slipped yet but who knows what'll happen after I'm kitted.


Re: 77 Peugeot 103 upgrading/performance

Sal RVA mopeds LLC /

This is the coil I was going to swap out to inside the flywheel. Came off an older Puch, type that the boot wire screws directly into. Managed to screw a bigger gauge wire in it. Writing on back reads 427 GERMANY 220421. Since this came off a Puch are there any mods I need to do to have this bolt on my stator properly and be spaced with the flywheel? Or does it just bolt up no problem? Also, correct me if I'm wrong> It's self grounding once I screw it in and the one wire coming from it gets soldered to the condenser right?

temp (2).jpg

Re: 77 Peugeot 103 upgrading/performance

#CrazyWayne™ rocks. #CrazyWayne /

Re: 77 Peugeot 103 upgrading/performance

sounds good man...

that kit looks awesome...

when you split the cases i'd use the paper gasket...it's a vertically split case so the paper seals better and gives you the extra clearance so you don't get any binding on the crank when re-assembled.

Re: 77 Peugeot 103 upgrading/performance

Sal RVA mopeds LLC /

Okay so the original size 103 needle bearing was too wide to fit inside the piston of that specific kit:( luckily enough i had a Tomos needle bearing laying around which was a perfect fit!

I didn't split the cases, just stuffed playdoh and case matched/added 3rd transfer for the kit.

Installed externally a new condenser to make it easier in the future! (this will stop my arcing)

Lapped the crank and reinstalled flywheel at .35mm points gap and 1.6mm BTDC

New bearings, seals, and points to install when that time may comes.

As of right now everythings done and I'm just waiting on 77mopeds to ship my pipe hopefully within the next month lol! Ill post later of the tuning and review of the kit I'm running!


Re: 77 Peugeot 103 upgrading/performance

Good job! I'd just run it with the stock pipe till 77 gets your pipe to you...

Re: 77 Peugeot 103 upgrading/performance

Bobby G, what pipe is that?

Re: 77 Peugeot 103 upgrading/performance

Sal RVA mopeds LLC /

Just the cheaper 77 circuit pipe.

Re: 77 Peugeot 103 upgrading/performance

Yeah run the stock pipe for now. I can pull 47mph gps'd on a stock pipe.

Re: 77 Peugeot 103 upgrading/performance

hey aaron...where ya been?

i clocked my 50cc kit with that top one pipe and the mbk cdi at 48.9mph the other day...but that was on a slight downhill...and i think i'm jetted lean...and i'm running saber...how long till it blows to pieces? lol

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