Blowing Up A Scooter Engine (On Purpose) - So We Can Fix It!

[@bb_adrians4672]

Another upload !! Those Hiper engines are too tough - i had a 99' zip 1st series, had a malossi mhr racing 70cc ac kit on it, stock crank with shot bearings, c16 and 21mm carb - pushed it to 110kmh and the ring broke. For a split second stuttered, but still ran me home. Low compression obviously, but the piston and cylinder somehow was excellent. Replaced the ring and went on my way!

[@scooterstreetau]

Yes we see this often, they always limp home.

[@uenko]

wow how long did you run the stock crank?

[@bb_adrians4672]

@@uenko 1 year and 5 months. Got the cylinder used, changed the ring, after 300km changed to a 2fast b size piston. Rode 1200-1300km. Before the mhr it was fully stock. Didnt even change the seals or bearings, just a new needle bewring Pushed it 90kmh+ and 10k rpm daily. 2023 september upgraded to a jasil evo hi-tech, after a month switched to an airsal 50cc. Those were good times 😇

[@dexietyy7922]

And yeah they are tough I remember few years back my 50cc hyper 2 engine siezed on me ( oil pump belt snapped ) i put some engine oil in with the petrol as it’s all I had at work and after a few kicks it fired back into life! Sounded awful and very rough but it got me home! Piston was absolutely destroyed but cylinder was fine!

[@scooterstreetau]

Nice.@@dexietyy7922

[@paulbudford]

Nice tutorial. Why do my circlips never go in that easy? 😂 I much prefer the way you have put the piston in the bore on this video. It's not always easy to see if the rings are seated correctly working under the scoot. Keep the videos coming. 👌

[@scooterstreetau]

Thanks Paul, Yes there are a few methods, this is easy if you have the surrounding space. Elevated scooter is the key.

[@1albasim]

best video to start my day with

[@scooterstreetau]

Ohhh Yeah👍 Waking up with smooth tones of Brad😂

[@phillipwallbank5]

Well done great video

[@nastynatesscooters9896]

I wish these zips were common in the us they look cool

[@scooterstreetau]

They never came to the US? Thanks for watchingNate🙌

[@nastynatesscooters9896]

There’s a few zips around the states, but not common like zuma ..

[@scooterstreetau]

The Zuma is easier to work on due to the panel constraints on the Zip. @@nastynatesscooters9896

[@oscarnygren6478]

Thanks again for time and effort spent on these videos. Always pedagogic and well explained☀️ Keep up the good work👍🏼 Question - in one of your videos when installing a 70cc kit on an air cooled piaggio you removed the rubber air inlet ”snorkel” from the airbox. Would there be any pros and cons from doing this? Have just installed a 70cc Athena pro sport, unresricted but original looking exhaust and sticking with the original 17,5mm carb (suggested in the instructions from Athena). Thinking about perhaps removing the snorkel?

[@scooterstreetau]

Thanks Oscar, yes we hope viewers can learn when we share our expeireinces. Removing snorkel offers more air and then upjet to balance the ratio. The 70cc can accept a higher capacity of mixture than the 50cc.

[@Vipex69244]

I have the exact same piaggio zip and i had my stock piston seized for about 1 year now without me knowing it ( i thought it was a variator problem) and i found this video and just now it stopped working and when i opened the engine cover i was met with dried grass.. which means the engine was not being cooled whatsoever

[@scooterstreetau]

It is very satisfyling when you find the cause🙌

[@js256scoast]

Hey guys love the videos. Have you ever come across a piaggio intake manifold not sealing properly??

[@scooterstreetau]

Yes we have, we sell a ton of new manifold and the rubber breaks down. We use grey heat gasket when fitting new manifolds to increase the integrity of the seal.

[@RD-qk4dh]

Hello, I have a gy6 Chinese scooter that is making a loud buzzing noise coming from the engine when going over 60 km/h , with a significant power loss, I have filmed a little video I can share it with you if you don't mind helping me out, I have changed the cylinder head, checked the valves clearance,the piston,the crankshaft, everything seems to be normal 🤷

[@scooterstreetau]

Isolate the noise area source. Is it the timing chain, Main bearing, a vibration from exhaust??

[@JamesAngell-c6h]

A quick for you mate is side to side movement ok on crank aslong as no up and down play as my top went caput today

[@scooterstreetau]

Sorry to hear it went bang, there is always small movement in all directions but excess movement is what we are looking for. The movement is bearing clearance. When the shaft and the bearing, cases wear this is where the excess movement presents.

[@JamesAngell-c6h]

@@scooterstreetau tbh wernt riding it was only started had 2 backfires and just died checked top end piston and bore was scored but tbf think someone who i had it off allready had it all apart as wasnt a top gasket on it so just waiting on fresh 70 top end tk come today and try that im hoping it dont need a new crank

[@scooterstreetau]

@@JamesAngell-c6h Check the lubrication system, look for all reasons why this has happened before fitting another pist.

[@JamesAngell-c6h]

@@scooterstreetau just check 2 stroke pump and its working so only thing i can is it was gone before i had the bike as ive not even rode the bike yet its only ever been started on tick over

[@JamesAngell-c6h]

@@scooterstreetau also engine only done 7thousand km which is about 4.5k miles

[@enduroiasg4068]

Hey I have aprilia motard 50 2t 2017 with 17kkm on it so in near future i was thinking about some 70cc kit and I noticed my splines on crank are not in good condition I think I might put the variator fan not correctly once when trying different weights. I want to build it for wheelies and some fun time in general. Can you recommend something? Budget around 500euro Only mods on it currently are somekind yasuni exhaust, lighter rollers 6x5g and stiffer 2mm springs in clutch, main jet is 60.

[@scooterstreetau]

Get the crankshaft sorted as it will hold you back from tuning and progressing. Check all over the engine and body and replace anything broken or worn.

[@enduroiasg4068]

@@scooterstreetau So, sorting crankshaft means changing it, and that means budget going to hell but im okay with it. What do you recommend? If im gonna go that deep what to upgrade along the way? And maybe convert it to water cooling. Thank you for the answear ;]

[@scooterstreetau]

Decide which way to go and then you can match the parts, if you want the same crankshaft buy a factory or similar and fit up with new bearings and seals to get ya back on the road. If you decide you love this then go for a higher class crankshaft and fit matching parts to suit.@@enduroiasg4068

[@enduroiasg4068]

​@rstreetau The worst thing happened that I didn't expect, reed valve broke at 45mph, I heard loud knock and the bike died :( I'm thinking going Airsal t6 70kit(don't know of this is bad) with Athena carbon petals. Do I need to worry about something more than main and idle jet? EDIT: Part of the spark hole thread fall into not the petals :(

[@martythemechanic]

You are the man 👌

[@AndreaFrassini]

I have a SR50R (2007 carb version with 5200km) if I want to change piston rings I had to separate the whole engine from the scooter? Thank you

[@MalavDesai]

Great video, I've just had to rebuild twice a month apart a hiper 2 Piaggio typhoon as the crank seal behind the magneto was leaking and letting air in or mixture out and caused it to lean seize multiple times until the piston was marred all around, mostly on the intake side suggesting lack of oil lubrication. Anyway I'd love to see how you guys do a leak down test. As before it broke down, I was having a hard time jetting it as the jets were so much higher than other builds I've seen.

[@scooterstreetau]

Hey thank you. Nice work! Great idea for a video. The seal leaking will give a false reading and also fluctuate the idle and accelration from low start. Glad you found out why.

[@LK1su]

I’ve got a little project piaggio zip 50 and it needs a piston replacement am I okay to ask some questions about it in the future?

[@scooterstreetau]

We try to direct people to the website.

I got a 4T zip. It's a shame Malossi and Polini don't have a 70cc kit available for it. If i knew this before acquiring my zip i would straight up bought a 2T zip. 😔

[@scooterstreetau]

Huh, both of these manufacturers do make big bore kits for the Zip 4T.

[@ryhu5642]

Shit.. I’ve had a fresh bottom an top end.. 172 tho basically sounds an cuts out like the start of this vid. Horrifying that I e paid a shop £1650 to do this 😭

[@sannikiboss4643]

hey i heave piaggio zip 1 dr70cc and yesterday i was riding it and it boged down turnd of at 30kmh and started light braking i dobt know if it is seazed because a kickstarter goes normaly down

[@scooterstreetau]

Get in there and check it out.

[@JamesAngell-c6h]

My engines doing this after rebuild would you say its crank thats gone as i can ride for 5 10 mins it just goes burr and conks out but starts back up instantly

[@scooterstreetau]

Your issue could be fuel or oil supply related. Check these components and then the piston.

[@JamesAngell-c6h]

@@scooterstreetau brand new oil pump ive also put oil in petrol to give oil pump time to pump right oil through its a brand new piston rides mint until it gets hot also crank had play thats why i think its a bad crank

[@secretsquirrel9722]

Is there a mild 70cc setup possible on these Zip's? I was a mechanic and capable of the work. I just need something to get in, around and out of town with. I was looking at a 70cc mod scooter because I could probably have it on road for not much more than $1500 with low km. 1, Could a mild set up haul 128kg of man around and up hills? 2, even if it can, should I do it? Or just buy something bigger out of the gate for over double the price? I've watched heaps of you vids but looking for some real world, first hand experience. How many km would you expect out of a well maintained and not flogged 70cc kit?

[@scooterstreetau]

Yeah the 70 kit and an exhaust will be fine.

[@secretsquirrel9722]

@@scooterstreetau awesome! Thanks for the prompt reply. Have you seen what sort of longevity people are getting with a 70 upgrade? 30k km? 100k km, lol?

[@scooterstreetau]

Piston and small end change at 10-15K@@secretsquirrel9722

[@LK1su]

What is best two stroke oil to use ?

[@scooterstreetau]

We use the original mineral 2 stroke, use race oil for higher spec race type engines.

[@mikeysmtb8536]

Hey, got a ac zip with 70cc mhr replica, yasuni r and 19mm dellorto and a few other bits. For some reason when taking off from idle going wot it stutters and wont rev up for a few seconds and then revs up fine and goes well, This only happens when taking off from idle going wot and wondering if any ideas on this.

[@scooterstreetau]

Test for richness and go from there. the entire set up can have this effect, air pod or filter and so many factors.

[@mikeysmtb8536]

@@scooterstreetau has stock airbox with mallosi sponge, main jet is nearly spot on but wondering how to know if it's pilot, needle or air screw not tuned correctly that could cause this

[@scooterstreetau]

Air screw should be set for idle run down. CHange a few things and see what the difference is. It is much easier if you do as I suggested and test for what the issue is☺ otherwise you are chasing your tail.@@mikeysmtb8536

[@numankralj]

Why does my Piaggio zip 2T 2016 model starts to accelerate the first 10 seconds when turned on?

[@scooterstreetau]

Auto choke.

[@numankralj]

@@scooterstreetau so is it working like it should or do i have to change it? But this only happens when de bike is cold.

[@scooterstreetau]

@@numankralj It maybe over reving, when you atsrt the engine ride slowly immediately and it should settle after 30 seconds or so. In cold climates the auto choke becomes more active .

[@sira6736]

I'd like to see the transmission2003 DERBI PREDATOR 50cc

[@scooterstreetau]

I have only seen one of the Predator in Australia.. RARE.

[@moonliteX]

Do a 4-stroke!