Compression and a pop from my exhaust?

Just been told it could be my piston rings?

 

possible could be a number of things.

only way is checking each part, start with rings , if they good, check plug spark, if thats good , check timing

 

Personally i would check spark first, then check your compression, then reeds, then maybe spark timing

 

I'm getting new spark plug today. if that don't fix the issue ill pop the head off and check rings and piston.

How do I check the HT Lead, coil, cdi isn't the issue on a Yamaha Aerox?.

When I kick the bike over theirs some sort of clicking, sparking sound which never happened before, sounds like when you press the spark on a oven and it clicks away.

 

as scuba said check rings ie compression test ( saves dumping the head and cylinder off)

new plug just pop it into the ht cap and rest against metal frame and kickstart, see sparking its all good, IF you see sparking and its coming from the lead itself to a ground thats a sign the HT lead is/has gone. you can replace just a lead they screw into the coil and the ht cap usually. coil test is multimeter job.

CHECK all electrical grounds, its not uncommon for a ground to become a little loose and cause grounding issues. clicking from kickstart area could just be the kickstart mech itself or its possible you have a sticky starter switch

 

I phoned ped parts and their now saying it could be a crank seal?. I changed my reeds over it wasn't then.

Do you know any videos of someone changing aerox seals and or how to split the engine to re do the seals. I do have compression, it don't just drop down with no compression, their is some there.

 

Is there a quick way to determine if your seals have gone?.

 

cyclinder gaskets if they go you tend to find it just wont work or runs very very doggish with just no power at all. a compression test would also show these especialy the head seal . only true way is pulling the cylinder and then in that case you would throw new ones on anyways ( just for sure sake )

most of the time we wrecked piston rings riding hard very rare we blew a gasket but then we would always change the gaskets when chopping in a new piston.

 

Head aint leaking. But how would I check for crank seal leak without taking the engine in two?

 

we run what is called a leakdown test

we block the exhaust port manifold off, we remove carb and on the carbs boot we fit a valve with a pressure gauge, we then use something like a bike pump to pressurize the crank, and we then sit and watch the gauge to see if it hold pressure, if after like 15 mins the pressure is still the same the crank seals are good. if the pressure drops its a sign the crank seals are leaking or the carbs manifold is not sealed and we have a air leak.

heres a video on a make shift diy leakdown on a puch two stroke motor, its the same sorta thing we would preform on your aerox motor to check for a seal leak without splitting the case and just replacing them anyways

 

Do you know all the tools I need to strip and rebuild?. gonna get started tomorrow .

 

Is this all the correct ones?

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Buzzetti Crankcase/ Crankshaft Puller Tool - £59.95
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Minarelli/ Yamaha Aerox Flywheel Puller (up to 2004) - £4.94
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Stage6 C4 Crankshaft Bearings/ Oil Seals Kit - Minarelli - C4 Race Bearings (polymer cage) £28.80
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sounds about right , you wanna make sure you have a freezer to hand and a hot air gun you can beg/borrow will help you get the bearings into casing.

grease , check your service manual your gonna need to grease things, two stroke oil , plenty of sockets and if you can borrow one a torque wrench so you can torque all bolts down to correct poundage.

i would wait and see if anyone else can add to the list of needed tools to buddy , mean while go and watch lots and lots of youtube videos on scooter engine splitting , please buddy really think about what your going to do here its a blooming big job and im not kidding .

you sometimes dont need to yank the crank to change seals. usually find seals are sunk in on the outer face of the cranks bearings, ( behind variator is a little black disc thats your seal fella - behind the stator on other side of motor is another black disc thats another seal ),
take off your variator and have a look behind it that little black disc is a rubber seal, how i used to remove them is with a dentists toothpick slipping it down into the seal and hooking it out ( not recommended) then a little grease on the inner of the new seal and a tiny wipe on outer of seal slip it over the crank shaft and use gentle tapping to seat it back inplace. ( have a youtube search on oil seal replacemnet without splitting engine ) you can buy a seal puller but when your out in the sticks like me we just cowboy'd ours out)

so fella do not be buying all that stuff ok think first act afterwards do some youtubing as a engine split is not a little task and things CAN GO WRONG !! check over vert removing seals on this gy6 engine first




this dude has some good videos but is not in english , so just watch them so you know whats your getting into with an crank case split
https://www.youtube.com/user/HasSse666/videos

 

The Problem I have is (tools) I have sockets etc and grease etc etc. but its things like gear guns, freezers, all them fancy tools as well I don't have. I would literally sit for a few days and quite happily learn how to do it so I can fix it myself. But it seems like it be cheaper to pay machanic to do it.

If I had all the tools id do it myself, but you sort of scared me away from doing it lol.

Looks really fun (if you know how to do it)

 

Could u also recommend a place to buy decent bike grease, lubrications and if so what make do I buy?. also do I need a crank shaffter puller for re doing seals or only to take crank out?

 

no all you want is a seal puller buddy , thats it a seal puller, slip it between seal and cranks shaft lock down the pin, give it a little press down and PoooooooP that small seal pops right out. as for grease you want a high melting point grease. motors get hot and that will cause a grease to become thin. the seal keeps water out and oil/petrol in so needs to be a high temp grease to stay sticky and do its job.

like i said just a seal puller buddy thats all your gonna need, you will only need to split the motor when the big end bearings fail and you gotta good few more miles before that happens .

If you really want to have a feel for splitting an engine, gumtree and a 20 quid dead chainsaw / weed eater ( 9-10 times its the carbs that have blocked up or the fuel bulb diaphragm gone ) , so get a carb rebuild kit, then strip it down and build it up, fit the carb kit and try to fire it up. if you have stripped and resealed the cases it should fire up no problems. that will give you a bit of experiance in small two stroke motor stripdowns and rebuilds.

But please do not split your roxy motor if theres no need to, replace those seals see how you go first buddy , and have a play with a little motor first before stepping into doing a scooter teardown

 

I took variator out..seal was nice and tight...took pump out no oil no mess. I decided to take the reeds block out and noticed I didn't put the reed feeler back in (the black pointy thing sits inside the reed block you get two sets with the stage 6 one.
I started the bike up and reset the carb mixture screw and played with the throttle to see if it cut out on high revs...but it didn't cut out. I dont see how I can go from having all those problems, being told its oil seal to now my bikes running again?.

Blockage, build up of some sort?. Fingers crossed it permanent

 

reeds not fully seating buddy.
the feeler kinda helps the reeds seat, if they dont make a flush fit they leak a little and cause problems.

ride it easy for a couple weeks ( no hauling on the throttle even if its a 70 kit ) so yeah take it easy over winter see how it plays, should find the feeler seated correct will now have the motor running sweet,

seal symptoms are like a reed symptom , can cause poor running / tickover idle / popping backfires same symptoms can be seen with poor rings and leaks so its more a check areas run compression tests - leakdown tests. good thing is you dont need to play with a seal puller/ split the motor or anything else.

but yeah just go for short'ish rides close to home incase it does start to play up go easy on the throttle and start extending the ride lengths im hopeful your good to go. and always take before pictures so you can go back and check if your re-fitting -tinkering

Scootz - stevep - scudabiker - myself would only crack a motor if its was a 100% needed otherwise we would just run a lotta tests to try and get to the bottom cause rather than have the motor in a zillion parts to find it was something more easy to fix. BUT if you still want to play with a motor see what its like an old chainsaw/weedeater is a good starting point. most mech will learn in college or on the job at a bike shop, some of us will watch others that have done a stripdown before and be asking a lotta questions.

 

Yeah PedParts did say air leak, seal, reeds is the issue for it. I changed the reed pettles yesterday but forgot to install the reed cusion/feeler. But it had feeler before that, and the old stage 6 pettles seem alright but again I'm not a professional...just seems odd after doing all that and re setting the carb etc worked.

I might buy second hand aerox engine to practice on for future reference. Got the buzz of wanting to do it. I think its good to learn anyhow, save you machanic bills.


The crank, bearings, seals, were fitted few months ago by machanic. so I'm hoping i can tick seals off the board now.

If it happens again ill pop it in to garage just to find out what the issue is before i spend any money...that way I can get a full diagnoses and if its cheap ill get it sorted.

Fingers crossed mate.

Yeah i will go easy on her, never really nailed the bollocks out of her anyhow...don't get me wrong I have opened the throttle up as we all do now again. but I don't pin the throttle back constsntly.

That dude hassse is massive help as well, I never knew how to do torque spring and it looks like something I could do with the correct tools. Gear ups look difficult, what's your opinions on them?.

Thanks for your help anyways buddy, you've helped me out loads!!!

Shame this website don't setup a whatsapp group or summit, so much easier that way.

Ill let you know how she gets on!

 

gear ups usually require you pressing the new gear ring to a shaft, problem is you dont get the shaft you have to use the one already in the rear box so your in need of a good press, they are press fitted with a very very tight tollerence , the pressure fitting is all that holds the ring to the shaft.

the ring must also be pressed on to the correct area, to much or to little it can cause binding where the gearbox plate wont fit OR worse still destroy the gear rings meaning a whole new gearset. to get a gear up fitted i would go to a mech they tend to have the presses needed and will have the time to fettle and press them off again if need be.

on a 70 kit they will extend your gear ratio so you have a longer ratio = a higher top speed, BUT you loose a little on accel because of this higher ratio. its not a huge difference but it can be noticed a little. then again you now find your top end speed has crept up and it takes a little longer to get there.

yes both hassse and vert have some great videos for you younger ones to learn from , things from carb set up to full on ratio adjustments, but you always need to be sure of your ability to carry out the job in hand. correct tools - time spare and willing to somewhat fly by the seat of your pants when things get rough and dont play ball like on the videos, what looks like a 45 min job could really be a 6hr job so videos do take away the real time aspect of builds , and you must take this into account.