Torque spacers: how do they work Rich?

[binthedirtnow]

Rich, I have this question as part of another one of my posts, but I believe you will be able to provide the best answer to the question. I tried searching, but I didn't get anything obvious that got into the meat of subject. The bike that may get the spacer is a 2002 kx 125, fmf fatty, jetted clean, 12/51 gearing, boyesen dual stage reeds, otherwise stock w/new top end. So, here ya' go.......

Now, I have a question about the torque spacer: How does it work?? It seems like it would reduce the crankcase compression by adding volume which could reduce the bottom end power(?). So, what change does it bring about as opposed to not using one? Unless I am totally wrong, but it seems that the spacer is installed between the reed block and the case, which would increase crankcase volume? Or is the spacer installed between the carb manifold and the reed block, increasing the volume behind the carb? I might forward this part to Rich....
B.

 

[Rich Rohrich]

The idea behind reed spacers is to increase the crankcase volume by adding a spacer in front of the reed cage. Anytime you change the crankcase volume you change the signal that the reeds see. Different reed materials will react differently to small changes in the crankcase volume. So the short answer is , yes adding a spacer will make a change but whether or not that change is useful, noticeable, or even positive based on your requirements is something only testing will tell you.

They are cheap and easy to install. Try it and see if you like the results.

 

[binthedirtnow]

Thanx Rich

OK. I can now make an educated decision. Thanx as usual....
B.

 

[mvmx]

Reed block spacer YZ 250??????

Is anyone running the stock reed block spacer when using a V-force 2 set up on a '03 to '05 YZ 250/265 ?

I'm running it without the spacer, but I'm always looking for more low end blast to roost the valve burners.

MV


YZ 265 EG with v-force, pc pipe + shorty silencer.

 

[steve125]

Torque spacers, ha! don't be fooled by the name. Like Rich has said, all they are doing is altering the crankcase volume. And in some cases positioning the reed cage in order to feed the rear boost port on non case reed cylinders more effectively.

Even though every engine responds a bit differently. Generally I have found this when testing with reed spacers.

1. Reed spacer in, smoother hit and sometimes better over-rev.

2. Reed spacer out, crisper throttle response, harder hit into the powerband and sometimes better over rev.

note: depending on how and if the spacer affects reed position and crankcase volume, over rev can be improved in either case.

I don't recommend reed spacers in 125's unless a smoother hit is needed for slippery conditions. I have never felt any additional torque on a 125 or a 250 for that matter, with a reed spacer.

On 250's they work well and I use them to help tune in the power delivery.

 

[stimps]

I've got a Uk YZ250. It never came with a reed spacer. Is it only the US versions that had them. Just gonna try V-force 3 reeds that protrude further into crankcase than the vf2. Wondering if the spacer would help. Anyone actually tried with and without.

 

[motolink]

Anyone used a spacer on the 04 RM 250 with a Vforce 3.

 

[bclapham]

Anyone used a spacer on the 04 RM 250 with a Vforce 3.

Steve has, and so has RC!!!! post that pic stevie! Oh, and Jay Clarke had one on the project bike last year.

 

[2-Strokes 4-ever]

Have Yamaha's reed spacer in my 03 RM250. Well worth the $20! Difference not huge, just enough. More torque, better roll-on..... 2-3 more washers in exhaust manifold will enhance low-end too (at slight cost in top-end)

 

[Rcannon]

The yamaha spacer is quite a bit thinner than most of the aftermarket models.

I tried an aftermarket spacer, Moose brand, and disliked it. The power was just too smooth. Never did find the extra torque it wa supposed to supply.