Reed valve

I have a PX150, fitted a Malossi 166cc, a SIP Performance exhaust, a Dell’orto PHBH30, the cylinder and the casings are ported together. The question is, as I bought a Malossi reed valve and manifold, do I have to match this port (engine casing and manifold? If yes do I have to do it to the maximum, Does anybody have some pics just to have an Idea?

The carb set up is like I receive it, factory setting.
I mean any opening, when I turn the throttle handle, the engine seem to be flooded and then just after the gas and rpm’s seems to be ok, I have to try this we when riding. I didn’t set it up good enough before, I would say that the set up was +/- % good.
I will see tomorrow nd sunday and will try to give you more information!

Thanks „Mister“ Curare,


Hello Curare,

I got the same problem with the manifold’s screw 1 millimeter to remove. I tried yesterday to start the engine, a little hard but then it starts but it seems to me that it will be hard o set it up!! When I give some gas on the handle, the engine seems to choke for a little moment and then it seems ok it gives much rpm’s but not any idle. Then it was he night so I’ll try to set it up on this weekend!! See Ya Mikkke

… „when you give some gas it chokes“ you mean a quick opening or something else, try to be more precise as possible.
And the carb set up was ok before with no reed mod?

hello Mikke,

to completely match the malossi reed manifold, you absolutely have to weld some material on the clutch side.
If you don’t want to weld you have to open it as much as you can. It will be missing about 1cm on the clutch side. But no choice. Weather welding or 1cm less large. It already works better then rotative with the inlet open to the max and no welding.
The problem I found with malossi reed, ( I have mounted 8 of them so I don’t think was a bad series) is this:
the back screw, the one that fit the flat base to the cases and on top of which you actually screw the manifold, it sticks out from its sits about 1mm! So it is not possible to fit the manifold if you don’t do some modification or have a different screw.
Check before mounting it or you would be p…ed off as I did the first time. Maybe the one you have it is ok but…
I found also out that with the Malossi kit it works better a combination of reed. In the standard form you have 2 x 0,30.
Keep one reed standard and change the other with next thicker one.

The other thing is that it will require you to learn a special technic to fit the carb in a way that you can secure it firmly.
All the time dry the rubber manifold inside from the mixture, and the carb and then thight the screw. To set the carb you will need to unscrew it out few times and if you don’t dry it off well the carb will slip out from the rubber manifold… now you know. But it is ok when you learn. The problem is that if you don’t expect it you think there is some woo-doo problem there.

hello Mikke,

please remind me your set up and carb mod. and jets.

…just another thing

just before mounting it put the flat base of the malossi manifold
on the cranckcase where has to go, you probably find out you will to take some alu away, then put the manifold on, and see if you have to trim away some alu from the side facing the flywheel.
With a dremmel it would not take it to long. Just be prepared. But you have to do it only once.