polini cylinder to vforce reed block to MLM intake compatibilit

John Lusignan /

Hey all,

Haven't done much work on 2 strokes and I have a few questions about this cylinder/reed block/intake pipe issue I'm having.

Bought these parts on the recommendation from treats a while ago and I'm finally getting around to this. '78 Yamaha Chappy lb50. Installing Polini big bore 70cc kit.

1. vforce 8 petal reed block bolt holes don't exactly line up with the mounting holes on the Polini big bore cylinder. Seems like an easy fix, bore out the holes on the reed block to align with the cylinder holes. Thoughts, tricks, tips?

2. Once the reed block is mounted the reeds closest to the front of the bike only open a few mm's (actually maybe less once I get the holes aligned) because the port is blocking those two reeds from opening. For this I'm hearing that there are spacers/risers that might solve this issue. Thoughts, tips, tricks? Resources for the correct riser?

3. The hole from the MLM intake pipe i bought is round. the vforce reed block is rectangular. Is this an issue? Seems like a bit of an abrupt transition that might impede air flow but I'm not sure. Again, thoughts, tips, tricks?

Thank you guys in advance!!!

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Re: polini cylinder to vforce reed block to MLM intake compatibilit

Dremel as needed and bolt on, ohh dont forget a couple gaskets.

Re: polini cylinder to vforce reed block to MLM intake compatibilit

Chamfering the bottom of the hole on the intake would certainly help with flow.

And yeah, holes not lining up exactly and needing to fabricate spacers is totally normal in moped performance parts land.

Re: polini cylinder to vforce reed block to MLM intake compatibilit

If you want get a different intake that matches the stuffer. What size is the intake currently.

Overall your thinking is spot on. I have a couple sets of Vforce that needed some help from a drill bit.

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