Suzuki 2 Strokes

OK .. where's those idea's

If there was only a flat face to fasten reed blocks to

My reed block is not here at the moment - it's spending time getting to know another workshop. I hope it comes back with some ideas.


looking at the back of that block, imagine creating a flat pad where each reed box would fit. Most of the surface is already there but he low spots will still need to be filled with weld or Epoxy.



A more significant hurdle is that the space where the attachment screws should be is right into the stud tunnels. That block was machined in as close as I could get it to create a stronger signal to the reeds, but moving it out say 6mm would create enough depth to attach the boxes.

That is effectively what you did by welding on three pieces of plate to the back of the block. If the reed blocks had then been modified or machined out of solid, they could be bolted straight onto those plates.

That would make it easier to swap out reed boxes to smaller or larger units or to ones with different angles.

The starting point for a reed conversion should probably be WHY? followed by WHICH?

The WHY is easy - because you can.

WHICH reeds to use is harder, but with the benefit of hindsight, it becomes easier. I used Reeds and blocks from a Polaris XCR600 triple. They were cheap and available and make 200hp on an almost identical 800VES motor.

The problem with that choice is that a GT motor in street trim doesn't have enough port area to support that sort of HP without a lot of work and expenditures of time and cash, both of which are always in short supply.

They are really large and take up a lot of space which makes them impossible to weld in place.




A better answer would be to look at a 125 or 250 motocross bike- say an RM250 or CR250. Those cages are large too but the motors are more tractable than a sled and replacement parts are available.

If I knew someone with a CNC mill, I would have had them machine up a set of boxes to take and RM125 reed cage and that would still be capable of making over 120HP on a 750 triple at the sort of revs a GT is more comfortable at.

Dave, what boxes did you use and what sort of HP can the donor motor make at what CC & revs?

As you already know Teaser but for reference i went with the smaller and more narrow reeds and boxes off the Arctic Cat snowmobiles , they use this design on everything from there 600cc triple to the big and powerfull 900cc Thunder Cat . Here is a picture of the stock cases before i sawed them up for the boxes .

This is the method i ended up useing to attach the boxes to the uneven intake face , instead of extra welding to fill the voids and then machine off flat i machined out aluminum plates to cover a area big enough to attach the boxes to and these also provided a area that i could blend the reed boxes to the size of the intake openings . These were welded in the area around the intake opening to the flat surface of the GT block that was later ground back to a smooth shape .

Another reeded GT750 engine built by Nova transmissions .

A experiment with Polaris 8 petal reeds mounted vertical

Dave - I see you engineered in water injection for the vertical 8-petal design....


Sorry - Thought I'd crash your thread.....

Tom Garcia wrote: Sorry - Thought I'd crash your thread.....

Hi Tom , your not crashing anything you have ( are ) doing real interesting reed work on the H2 engine and now your twin so add anything here about reeds .