Aerox help

yeah i ordered a malossi variator its on the way and yeah i got 16x13 rollers

i can get polini reeds for some break pads off a wrecking aerox with no engine or anything plus $15 cash my way would it be worth it?

 

so i was fiddling around with my other aerox im trying to sell at the moment because after doing a few engine swaps with frames and finding out its bogging :/ so ive been trying to tune the carb its just a stock 50 aerox, ive manager to make it a little bit better but the whole cylinder was covered in orange coolant staines and my coolant was like orange when i drained it :/ and really hot, so i decided to change the cylinder and cylinder head with one only done 5000kms tops compared to 18,000kms, the piston and crank are still all in good condition, i can sometimes full throttle when riding it and itll go off abit but its very very boggy and not good to ride and i just cant figure out how to tune it, i might have changed the jets or its dirty inside when we took it apart?

 

It's all about air tightness. I keep saying it but you really need
to use new gaskets and sealant. Just gaskets are not good enough. I use
CAFF red sealant on all paper gaskets - putting a thin film on both
sides with my fingers before assembly. This applies to the admission stack, pipe, reed box too.
The big rubber 'all in one' head seal is also a classic P.O.S. When I
replace head seals I also tickle them all over with sealant on my fingers
before assembly.
The nitro head is also no good. Apart from the fact that it doesn't have a propper squitch band, it's not massive enough. It's a good idea to resurface that
thing every time you rebuild.It distorts very easilly and pisses coolant - even with new seals
seals and sealant.
I use a 10 mm glass plate with emery paper spray mounted
onto it. A bit of WD 40 and then you work it until you can see that everything is flat.
I generally do this to the top of the barrel too.

All the problems you describe can be solved with these methods.

 

I have a metal gasket on the exhaust tiny bit of air at full throttle comjng out but thatd it

 

Any gas leak is bad on a two stroke and robs you of power and economy.

Get some gasket sealant (Hylomar or Hermetite) and some exhaust paste, the stuff they is used to seal car exhausts (Firegum).

Take the head and barrel off again and put the gasket sealant on both sides of all gaskets, including the reed block gaskets and re-assemble the cylinder. Put a smear of Firegum on each side of the exhaust gasket, bolt the exhaust up and run up the engine to heat up and cure the Firegum.

Your engine should be fully gas tight then.

 

And surface the head. I'll bet it's bent. This is a recurring fault on Nitros. That's why it's losing compression into the cooling system.

 

Yeah, I agree with Turbovetto.

Get a sheet of flat glass and lay some fine wet and dry sandpaper on it, then place the head on it and work the head across the sandpaper in circles a few times, so that you don't create scratch lines on the head. Check that the head gasket surface is smooth and matt grey finished and that there are no parts that haven't been sanded that may indicate that the head is warped.

 

Exactly right - a few minutes - or until you get the uniform matt grey finish all around. Lube helps. As does constant even pressure.

 

@ Turbovetto

You can tell I've done this before, can't you?

 

Likewize !

 

ok so i bought some exhaust cement paste today crc brand i think, some Hermetite exhaust spray sealent, a new set of cylinder and exhaust gaskets but they were malossi ones im not to sure if they fit the stock 50 cylinder, the rubber gaskets just slip straight on and theres a little bit of a gap where they sit in the grooves but they dont fall out but still, i havent put it back together today just taken it back apart and have got the whole cylinder off , i dont think im qualified enough by myself to resurface the head and piston but i coudl give it a shot, has anyone got pictures on a diagram/example sortof?

 

my scooter is still being normal and very good and then once i ride straight without stopping for more than 5-10 minutes it starts bogging, if i stop at traffic lights the takeoff is good again aswell sometimes i think when i mix oil or abit more with my fuel it runs abit better like if i run it without it the problem is way worse ( my main 70cc scooter )

 

Sounds like it's a bit poor. Spark plug colour ?

 

its not black but a very dark brown not the cappicino colour eveyrone says is right though, have i mentioned the tuning screws on this new 21mm dellorto black edition carb have not been touched since its been put on the scooter? could that just be my problem? all we have done is changed the main jet from a 92 to an 88 im not sure if its correct but made it better

 

It sounds like it starts bogging down the minute the auto-choke cuts off. Check for an air leak at the inlet manifold to the carburettor.

Also try lowering the needle one notch on the throttle slide to see of that helps.

 

its a manual choke btw

 

yeah im gonna fiddle with the idle screw and idle mixture do u think a 88 jet sounds about right?

 

If the take off is OK i'd leave those alone. What I would do is find a long straight - go down it at full blat and then cut the ignition (while you are at top speed). Then unscrew the plug and have a look. If it's black / dark around the porcelain insulator - and the L shaped contact at the bottom - then I'd reduce the main jet from 88 to 85 and try again.
What you're after is a brown brick colour - with a darker colour around the edge of the bottom.

Once you've got the full speed right with no more bogging when it's warmed up - and the plug is the right colour - you can then have a twiddle with the mixture screw to get the best take off. 1/8th of a turn one way - better ? Repeat until you get the best take off. Worse ? Go back where you were and go the other way. The mixture screw only affects the first part of the take off. And it's pointless playing with it when the principle jet isn't right.

Good luck -

 

The technical term for what Turbovetto is describing is a 'plug chop' and it shows you the mixture at full jet open setting.

 

Ive been told it could he the rollers being flat, ive got either a malossi variator or a polini 9 roller super hi speed