Polini style reed valve upgrade?

(Casserollers) Gregory B. /


This is going to be an extremely dumb question, but...

How... does... this... reed... valve... upgrade... actually... work?

I'm new with tuning everything and slapped on my Polini kit, but... just trying to learn things here, so don't blame me if it's a stupid question. Just want to know how things work.

What are the effects of upgrading as well?



Re: Polini style reed valve upgrade?

Actually that is not a stupid question at all, and unless u are familar with 4 pedal polini reedvalves your not going to know.

Basically a standard 4 pedal polini intake is actually a large 2 pedal system with 4 windows, it is made from cheap pot metal which is prone to cracking and breaking, and the reeds are riveted on so they cannot be removed or replaced, w/o grinding away the rivets and retapping the hole for screws, then grinding the screws.... well its a bitch ok. And the standard units come with a louse 2 "O" ring style seal that almost always will have an airleak requiring the use of silicone or rtv sealant.

Now this upgraded reed block 1977 has is much higher quality than the standard one. First off its a true 4 pedal system with 4 individually flapping pedals, second it is not made from metal (or at least I can't tell if it is) its made from some kinda of high desity rubberized plastic or carbon material, so its a lot less prone to breaking and or cracking due to heat and vibration, it should also have a better seal than the standard one to help prevent airleaks. Lastly this upgraded version has screws that hold the reeds on so that you can actually replace them when they get old and worn or chipped etc. Or you have the opportunity to install boysen reeds, or different thickness reeds, so its alot more tunable than the standard one.

Basically I would buy this (and have in the past bought it) when your standard 4 pedal block, A. either fails, or B. the reeds get chipped/wear out. Not only do you get a new block but a better one too.

If you got some money to spend and are going 4 pedal polini on a bike you might want to just pick this guy up as well, especially if your going for max power, and max tunability, reeds can make a big difference on ur setup. reeds are to the combustion chamber as the points are to the sparkplug, its very important they are maintained and tuned appropriately.

Re: Polini style reed valve upgrade?

oh and btw that reed block is a direct replacement upgrade for the polini 4 pedal pyramid style reed block that comes on the polini 4 pedal reed intake setups, and not compatible with the 2 pedal flat systems that come with puch polini kits stock.

Re: Polini style reed valve upgrade?

o and i guess one last thing to mention about tuning reeds in general is that thick or stiff reeds will allow the motor to have higher rpms, and One the other hand lighter thinner material will produce more tourque at lower rpms but start to flutter too much at high rpms and in effect limit the top speed.

boysen reeds are a hybrid reed with a thick one that has a hole in it and a light one on top of that. the idea is the light one will work well for torque and the thick will help for top end. how well this works on mopeds is up for debate.

Personally i prefer very thick non boysen single layer carbon reeds.

Re: Polini style reed valve upgrade?

🇮🇹💦 Of the Loin /

fyi the boysen reeds dont work dually on mopeds, unless you cut out newholes in one of the reeds.

Re: Polini style reed valve upgrade?

"the boysen reeds dont work dually on mopeds" what do u mean?

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