Scooter PAIR valve issue

[Gezza]

Hi guys
I'm hoping someone here can help me with my problem.
A week ago my scoot started making a hell of a noise and i was thinking it was an exhaust issue. On looking at the exhaust all was fine and looking under the seat i see the PAIR valve had melted. I had tried looking for parts (Keeway) and see they were almost non existent so decided to remove all the junk associated with the PAIR valve. I also read the a hole in the cylinder head needed blocking off (exhaust i believe) and a vacuum feed on the inlet manifold needed to be blocked. Since doing this it's been a right pig and wont rev and is unrideable. I'm going to take a guess here and say that the carb may need re jetting but i'm not sure.

Hope someone here can shed some light fore me

Regards
Gezza

[FJRider]

If the reason you bought it was because it was cheap ... you got what you paid for.


Longevity is not a Keeway selling point.

Find a second hand engine that runs ... even that might be harder than you would think.

[speedpro]

Seems a PAIR valve simply lets air into the exhaust pipe, undoubtedly for emissions. Removing it and plugging the holes shouldn't affect the tune. I'm thinking there would be 3 holes but haven't found a diagram so just guessing. 1 to the exhaust, 1 from the airbox or intake duct, 1 from the engine side of the carb or throttle body. If the old valve melted then something probably got stuck open allowing hot exhaust gases to flow back to the valve.

Something to try might be reinstalling everything and just blocking the hole in the valve which leads to the exhaust.

[Gezza]

Thanks speedpro. Appeciate your thoughts
Gezza

[Gezza]

Speedpro

Thinking now probably the reed valve packed up which has let hot exhaust gases get to the valve and melted it. I have since blocked that orifice and it hasn't run properly since. Feels like it's not getting the gas when i accelerate. I will keep trying to sort it.

Thanks again
Gezza

[Dak S83]

Dunno know if this is at all similar to yours https://www.youtube.com/watch?v=Plt1VHSxS44
Or this one https://www.youtube.com/watch?v=ubUosWJUhM4

If you've done it similar to those removals it should run fine.