Aerox help

So I have a 2009 yamaha aerox r and have recently hit something and my exhausg is really loud and the thread coming out of the cylinder is bent but that is not the issue I put another leo vince zx on ( same pipe as original) and now I have lost alot of power but sometimes it will go good off the start all the way, aswell to mention I have a malossi 70cc kit, uni pod filter, 19mm carb, leo vince rollers, clutch springs

 

Does the replacement exhaust sit properly on the old exhaust gasket, so that it seals properly? A really loud exhaust hints at a lack if a good seal between the cylinder and the exhaust. Ideally you need a new gasket as the exhausts are never the same fit, but a touch of exhaust paste from the local car shop might save the day, if you put some onto the gasket before you refit the exhaust.

 

I agree with Merlin but also check the head for cracks because if youve hit it hard enough to bend the threaded bar you could of damaged the head

 

ok thanks ill check the head, it used to have 5 gaskets on it because it was leaking for some reason when the previous owner had it and i only used one for the new exhaust and its not really loud that was the old one once i hit it im just wondering why this loss in power for using the same exhaust, should i try with all 5 gaskets?

 

if you bashed the pipe you've probably sort of restricted it. Might be time to have it off and de-restrict it by bashing it from the inside.....

 

5 gaskets?????
On the exhaust manifold?????
How long were the friggin bolts then????

 

this pipe i have on it now the replacement structurely is perfect no dents in this one

yes 5 gaskets he said because when the exhaust place grinded it flat again they made a little indent in it and it keeps leaking have a look at the flange and you will see what i mean.

the bolts come out of the cylinder and are unscrewable aswell i just used a normal bolt that screws in for a replacement of the bent one i unscrewed

 

Possibility of a photo of this please? Also the name of the place that did it so i can steer clear of them.

 

ive just taken it to the shop to get the brakes done and he had a look at the exhaust and the cylinder is in perfect condition no cracks and he replaced the gaskets with one gasket and no air is coming out anymore so we can rule the cylinder and exhaust out of the equation, what i think it could be is because i noticed just after it happenned when i was checking the whole bike that the clutch mustve overheated or such when i was pushing top speeds of around 110-115km real speed, it has sortof blue burn marks and it is quite abit wavy which could explain why most of the time it shoots off like normal and at 50km it just dies and is really slow until about 70 and then it starts to pick up again like normal but sometimes it doesnt slow down at 50 it goes all the way

Thanks

 

what is a way to remove the clutch bell without the proper tool? ive got the right socket to fit on the nut but it just moves when i try to undo it, ive tryed clamping the clutch bell and untightening but doesnt work

 

Use either the proper tool or an impact Driver, proper tool is far cheaper

 

ok

 

You could always buy an electric impact wrench. Just a suggestion, you could buy cheaper ones.

http://www.machinemart.co.uk/shop/product/details/clarke-cew1000-electric-impact-wrench

 

ill probably just go to my local scooter shop and get the tool off them, is the upgrade worth the money in buying an aftermarket ( malossi in mind ) variator and clutch and not sure about clutch bell or not, havent fixed the problem yet hopefully for now just put mu spare stock clutch i had on a spare engine all i can see is the clutch bell is burnt and abit deformed could that be causing the problem?

 

This is not the clutch. This is the MBK corrector (the rear spring variator). Your description sounds far too familliar.

If you remove the rear variator and unbolt the clutch and remove the spring and then the steel sheath (use 2 flat screwdrivers) you will find two little pins which slide in two slits (or rather - the pins determine how the sliding part of the rear variator can move open). The angle and shape of the slits determine how it behaves (opens) since the angle & the shape of the slits determine the mechanical advantage the spring has over the rollers in the variator (which are fighting, with the help of the engine, to prise apart the two running surfaces.

On the standard yam/mbk rear variator, the slits are boomerang shaped. Steep at the start and then at a different, shallower, angle. These change the mechanical advantage the spring has over the rollersThis has the effect of making it harder for the engine to open the rear variator fully at the start (so there's more slip and the revs stay high) but easier as the speed picks up, thus restricting top speed (you can't accelerate in a car if it's in 5th) and at the same time keeping the engine in the (low rev) power band for minimum rpm and wear at high (well - 30 mph is not what I'd call 'high') speed.

Since your engine is much more powerful than a standard engine - the rollers win the battle too easilly (when the corrector suddenly opens wide - when it gets to the change in the angle of the slits in the corrector - and so you've effectively changed from second gear into fifth (to continue the car analogy). This consistently happens at or around 30 mph. You claw this back eventually - but you have a big 'hole' in the acceleration because of the power band nature of 2 strokes and the clever configuration of the standard transmission. Any changes in performance (sometimes it goes, sometimes it has the hole and you wait for the engine to pick up the revs) are due to belt temp (worse as it gets hotter) and weather (engine produces more power if it's hot/cold according to set up). Obviously - the terrain counts. Go down a hill and you hardly notice. Go up a hill and - oh shit.

If you look at a Malossi rear variator (which has three pins, not two - which is also good news), you will notice that the slits are steeper - and more importantly, straight. This means that if you set the rollers so they are perfect from 20 onwards (when the clutch has glued itself to the bell via inertia and ceased to be a part of the equasion) you find that the engine remains at a constant RPM right up to the point where the variator is fully pinched and the belt is all the way down at the back (nearly full speed). The hole you describe is gone. The acceleration (and RPM) will be constant - all else being equal.

This is why it's essential to get:
1: a decent variator - front & back (Malossi Overrange is the reference - and I've tried pretty much everything else)
2: A gear up kit - so that the engine stays in it's power band for longer (more top speed - and better mid/high speed acceleration.
3: A transmission box with needle bearings (Top Perf Nardo is the best bargain).

Hope this helps. I had exactly this problem when I kitted both the Neos here (one is an air cooled top perf cylinder, the other is either Stage 6 Sport Pro II or Malossi MHR Team II - I have two complete engines for mine) - and it's exactly the same as the Nitro. Only the final gearing changes is the Nitro - and it's like 3 percent longer ratio. This is why you're better off getting a Piaggio - but with a bit of effort (and money) you can correct all the bugs.

So do not waste time / money on the clutch. It's stopped slipping at 20 mph max. No more heat. It's getting hot because you've regulated the rollers so they are OK and you can get past the hole (more or less). Which means that they are too light at the start (too much slip everywhere) and too heavy in the middle. This is why it's such a bitch to set up a 'rox with the standard transmission and a decent kit/pipe. It's that bloody rear variator with the boomerang slits.

 

That was one of the most interesting reads i've had in a while.
Thanks Turbs

 

Thanks Steve - bitter experience I'm afraid !
I'll try and post some pics to illustrate this. I have umpteen stock correctors and a broken Polini Speed corrector in the garage somewhere. The difference is not subtle. Apart from the fact that even stock correctors are better made than big diameter Polini race versions at I-don't-know-how-much a pop. Grrrrrr. But that's another subject !

 

Thanks for the info, i changed the carb to a 21mm dellorto and the problem is solved, the old carb that was 19mm was actually a 4 stroke carb slightly modified to fit into a 2 stroke scooter with glue and other stuff it shouldnt have been in there in the first place, the guy at the shop thinks it couldve been abit of glue cracked off when i hit that pavement and gone into the carb or something

 

will there be a big difference if i add a malossi variator and a malossi clutch bell and clutch

 

Ah well - there you are. Midrange carb trouble. Hey ho.
Yeah - the standard variator is a piece of junk - and a Malossi will improve everything. But if your take off from 0 to 20 is good - forget the clutch. It's fine.