Aprilia area 51 speed issue

Hi guys,
This started but didn't ride when i got it so i stripped the engine put new bearings in rebuilt it replaced gaskets put in 5 gram variator rollers in as they were flat put in a new belt and a new ish clutch now it starts but it does not like a cold start prefers choke for a while problem is it now goes flat out 25mph now i know when i got this it has a 70cc head and piston fitted but it only has the standard carb i assume that this is the issue and if so should i take it back down to a 50cc or am i missing something?
Any help would be great.

 

Been a while since i was here the wife has had lengthy illness so pretty much it hasn't been touched until now.
Since this post i have took it back to a 50cc head and it runs flat out at the same 25mph lmfao
hopefully some of you guys have any ideas on were ive gone wrong or what im missing i have recently noticed that the variator spacer and the blue steel washer was missing the washer is on order hopefully here tomorrow haven't found the spacer online as yet unless its insane postage prices but as i understand it this is a restrictor spacer anyways so hopefully not needed (or is it?)
Please any help would be great id love it on the road for spring

 

this could be anything to do with your drive belt, rollers, carb, your fuel lines or your air filter. i had a problem with mine not getting power and it was my air filter so i changed it to a standard pit bike air filter runs fine although my bike also doesnt like the cold

 

Does the needle lift all the way up in the carb?
And does it go faster if you let off the gas a tiny bit?
What exhaust has it got? Could be choked up in there

 

Sorry for the late reply well i did have problems with the carb overflowing bought new float and needle but still leaked so i bought a new carb. Now ive stripped the clutch and noticed it had red springs while the contra spring was black i dont know if this makes a difference so i bought a 3 pack of each black/white/red to replace not sure on what springs to go with there also bought malossi 5.4g rollers and a new drive belt it has a leo vince tt exhaust i did have a standard ebay one on it i wasnt sure if that was also an issue

 

That thing should fly, few questions for clarity..

When you say 25mph flat out, is that sounding like its at a million rpm and about to explode. Or, droning along and just wont accelerate?

How does it sound, when you blip the throttle is it crisp and sharp like a motorcross bike. Or dull and flat?

Does it smoke at all?

Easy to start?

Ticks over ok?

Comes back to idle quickly?

What filter is in it?

You say new bearings, crank? little end? did you replace the actual crank ( actually normally a pretty good idea considering how cheap they are).

 

That's a bloody good question.
I was just assuming it's choking out. But the belt could be totally loose and its revving it's tits off...

 

Or that clutch could be slipping like crazy. Oil or whatever will do that

 

Right yes at 25 mph its screaming its nuts off it takes about 30 seconds to start up if left once it starts it idles ok and seems to rev ok it seems to sound ok i dont think it smokes too bad just typical 2stroke smoke it does have the standard filter in also yes i put in new crank bearings and piston+rings.
I have checked the clutch just in case and there is plenty on the clutch however that has yellow springs but the contra spring is black i assume this is not correct i have bought new ones 1000rpm/1500rpm and 2000 rpm white/black and red what ones should i go with assuming this is part of the problem?
i hope i have answered the the relevant questions

 

Try sanding down the clutch shoes a tad. Just incase they are glazed real bad.

 

Try the 1k ones first.

 

ill get on with it over the weekend and hopefully let you guys know how its gone just a quick question just popped in ...what would the ideal jets be for the carb? it is a new one so i havent looked inside it

 

No set answer for that question. It's a dynamic thing you know.

 

Well guys what i failed to notice until now is the fact that the contra spring was definatelly the wrong one(see photos).
i think the previous owner cocked up there i can assume that this is a factor behind my problems

 

Wait. Huh? I never knew direction of the spring spiral made a difference. Learn something new every day I guess.
Nice find

 

the old one was a lot bigger mate didnt fit no were near not sure of the direction tho...

 

Sounds like its too strong, the winding direction wont mean zip, its a compression spring. All it does is up and down, it doesent twist.

If its a really strong spring your engine may not have the balls to push it back and get into 'high' gear.

 

Well with some luck clutch,rollers,carb and belt n everything else ive done fingers crossed it will run ok i did put new fuel pipes in flushed the tank too so if it could be a fuel problem the only thing i haven't done is check the fuel pump and the reed valve the reed is clean like new so i cant see that being a issue but knowing this scoot ya never know lmao

 

New problem ffs.
Right i try to turn it over and nothing so i took the fuel line off the carb n turned it over to find no fuel coming out at all so i thought id hook up a large syringe to some fuel pipe injected some fuel in and low and behold it started then i noticed fuel coming from the pipe that should have been connected to the carb its winding me up loads now the pic below shows the bottom black braided line comes off the tank orange middle vacuum and the orange/black to the carb im sure this is this correct but not 100% if this is right any ideas what could be causing it?

 

All pipes are clear filter clear also new carb just thought id blow through the vacuum pipe while still connected to engine blew through that deep breath clear
Its a stupid question i know but if you blow through that vacuum hose should it get some pressure behind it as i can blow continuous air through into the engine ive never had to check this before?
any help would be great