Persistent Jetting Problems

just looked at your video again. That's a stock-ish airbox with a malossi filter. you can ignore all my previous advice on jetting.
But the fact remains, your scoot is too poor. Now that's not normal with that air box and. 90 jet. If you haven't removed the snorkel in the air box, 90 should be too rich.
So I have some theories.
Those symptoms can be caused by an air leak. This can be anywhere- from the base of the cylinder to the admission pipe/ reed box.
or the airbox itself if not done up tight/ right. it all has to be air tight and capable of remaining so at more than 2 bars of pressure.
The other thing it could be is lack of fuel/low fuel level in the carb float bowl- but this is rare.

what have you done to the scooter recently which could account for a leak ?

 

Apart from installing the crank,cylinder and the other new parts, no. The strange thing is as i said before that it was running fine at first. Problems started when i installed the malossi filter. What do you mean

 

stop stop. These problems began when you put a new crank in and rebuilt the engine ?

 

No no, when i installed the crank and such i was running with the airbox, and it was running good. After i removed the air box and installed the air filter (malossi) it wasn't running well.

 

Ok i looked at your video again and i can't tell for sure what you are using as a filter. is it or is it not a red foam open filter?

 

This exact one.

 

Right. i have no idea about that one because it's kind of neither fully open or fully closed.
Assuming you have no air leak gremlins, your scoot, based on the video, is too poor. Of that there is no doubt.
So you have two choices:
Jet big and work down, or go back to the stock airbox with the last setting that worked.
if you keep that air filter, start at, say, 120 and work down. To make life easier at the start, you could lighten the rollers a bit until you know roughly where you are with the carb, and then load them back up, keeping a careful eye on the spark plug colour. More rollers loads the engine more and it will get thirstier. Do not cane it until you have everything running properly with a chocolate plug.
Also, white springs in the clutch are not stiff enough. You need red or black.
Good luck.

 

Should i remove the snorkle from the airbox? Also what does it mean if with the 100 jet the scoot does not do this wierd sound but does not move at all or moves slower than a turtle? In addition, i'm suspecting something went wrong because i think there are some marks under my scoot my, which i suspect is petrol.

 

If you put it back the way it was, change nothing. Leave the snorkel and put in a jet you know works.
But find out where the petrol is coming from. Could be a clue.

 

If the float chamber is leaking, could that cause it?

 

That filter is pretty much like mine, even tho mine isnt a malossi, and I use a 112 jet. Turbovetto is right, if its doing that, its too poor without a doubt. Try a 120 jet and see what gives. Also, try this: crank the scooter a few times and see if you see petrol leaking thru the carb. When i was assembling the exhaust on my friends stalker that happened. Im yet not sure if it was a stuck float or whatever, but after re-assembling the carb it got fixed. If it doesnt happen, maybe its dropping from the open filter itself, due to the lack of backpressure

 

How can i understand if 100 or more than 100 is rich? Cause as i told you, when i installed the 100 main jet, it would not act like it was gonna shut off. It would rev when i opened the throttle but not move. In contrast, the 90 main jet acts like its gonna shit off when i open the throttle, so my attention goes to a possible error when i changed the jet, like not closing the float chamber well. Could that be the cause of this action?

 

Quite possibly. Check everything & have another go. If it's too rich it will splutter and cough. If it's too poor you'll get the 'beuhhhhhh' sheep noise in your vid.

 

I tried the 80 main jet with the stock air box and the symptoms were like the 100 jet with the open-air filter. Very sluggish, slow .

 

Quick stupid question : Every time I change the jet, the float chamber has to be closed right? It would be such an easy task if you could try the jet without putting back the float chamber. Especially when you don't disconnect the carburetor and try to screw/unscrew it back with many things in the way!

 

Yes - it's all got to be tight. All the collars & clips, all the nuts on the carb. Everything.

 

Hey, so i had a look at the float chamber and it's leaking. I removed it and put it back together and it's still leaking. Any suggestions?

 

re-surface it on a sheet of glass with emery paper on it & some turps to lubricate - then check the rubber seal - replace if necessary.

 

Could you re-explain please? I didnt understand. By the way, it's working fine now, not shutting down or making that noise in the video.

 

If the bowl is leaking, remove it. remove the seal, put it upside down on a sheet of glass with a sheet of new 400 grade emery paper. put a drop of turps or oil on there and move the bowl around in a circular fashion perssing on it lightly. The flat emery paper surface will plane the bowl edge flat.
Clean scrupulously, put the seal back on ( or replace it if it´s knackered) and hey presto. No more leak.