These are the dual material reeds. Carbon fiber on top and fiber glass on the bottom.
I installed these on a 1993 Rm 250. I purchased the bike used last month and don't know it's history or mods. The bike smoked some and ran rich. Otherwise, it ran well. Knowing it needed a rebuild I waited to re-jet.
The bike came with a Pro Circuit Platinum pipe. The top end rebuild was done approximatly 5-10 hours ago courtessy of Eric Gorr and Fast Forward. Piston, rings, replate and repack the silencer.
During the rebuild, I noticed reeds had a slight curl to them. I'm talking dollar bill thickness here. (they were all fiberglass, I assume boysen as well) They needed replacing soon, but the budget didn't allow it at the time. Plus they seemed serviceable with no cracks or chips.
The bike still smoked and ran on the rich side, even after the rebuild. I concluded it must be the reeds.
Jetting before the reed install was:
Main jet: 180 RD
Needle: R1471NS clip in the #2 position (one lean from center)
Pilot jet: 52
Airscrew: 1 turn out
The install was straight forward. I just followed the easy to read instructions. Boysen recommends using "blue" lock-tight, so I did. Boysen even includes an overview of the jetting process and some jetting suggestions. They also include a toll free tech/jet support line. I thought it smart to test ride the bike before playing with the jetting.
Jetting after the install is:
Main jet: 180 RD
Needle: R1471NS clip in the #3 center position (suggested baseline)
Pilot jet: 52
Airscrew: 1 1/2 turn out (suggested baseline)
I just got back from a test ride, and all I have to say is WOW!!! I have to move my seating position farther forward. The front wheel can be lifted with a twist of the throttle, where before it needed some clutch fanning. The bike used to bog some on low rpm hill climbs. Now it motors right up. The engine seems to run smoother and sound "less reedy"as well.
Jetting seems to be good so far. I didn't get to test as thoroughly as I wanted to. I checked the plug, it's mocha/tan and dry.
-Quality of the product is great.
-Install is easy, just follow the instructions.
-Time, only took an hour.
-Would I recommend it, you bet.
A great bang for your $40 dollar "buck"
Hope this helps some, Steve.