YZ85 reed valves.....are they worth the effort?
Moderator: rztom
YZ85 reed valves.....are they worth the effort?
Original Yamaha YZ85 reed valves.
Are they worth the effort in grinding intake area to make them fit?
Is there a noticeable increase in power anywhere in the powerband?
I am planning on having TSA (if he can build them soon) or Jolly Moto pipes and a Zeel ignition....stock carbs.
Most of the pictures of this info have been lost to various photo hosting sites.
Are they worth the effort in grinding intake area to make them fit?
Is there a noticeable increase in power anywhere in the powerband?
I am planning on having TSA (if he can build them soon) or Jolly Moto pipes and a Zeel ignition....stock carbs.
Most of the pictures of this info have been lost to various photo hosting sites.
78 GS1000E
80 KD80
82 Katana
84 RZ350
84 RZV500R
86 GSXR1100
86 1100 sportster
88 FZR1000
89 RGV250 VJ21 SP
90 RGV250 VJ22 SP
91 TZR250 3XV2 SP
96 RGV250 VJ23 T SP
99 RS250
02 Hayabusa
16 KTM 390 Duke
17 KTM 1290 Superduke GT
21 Aprilia RSV4 1100
80 KD80
82 Katana
84 RZ350
84 RZV500R
86 GSXR1100
86 1100 sportster
88 FZR1000
89 RGV250 VJ21 SP
90 RGV250 VJ22 SP
91 TZR250 3XV2 SP
96 RGV250 VJ23 T SP
99 RS250
02 Hayabusa
16 KTM 390 Duke
17 KTM 1290 Superduke GT
21 Aprilia RSV4 1100
Re: YZ85 reed valves.....are they worth the effort?
I did the mod on both my bikes, But I'm running PWK28s and BT pipes, heavy porting and Gus heads etc on one and Mikuni 34mm, Toomey pipes, heavy porting and Gus heads on the other, I dont know if they make a difference without all the mods, But more air cant be a bad thing... Just take a look at the size of the reed blocks on an RGV250 or any modern two stroke dirt bike, They are bloody huge compared to our little cages, Im sure they made them bigger for a reason
1985 RZv500
1984 RZ500 Hybrid
1986 RG500 Walter Wolf
1986 RG500 Skoal Bandit
1984 RZ350
1984 RZ350 Hybrid
1981 RD350LC
1981 RD350LC Hybrid
2009 CR500AF Supermoto 250X
2007 CR500AF 250X
1988 YSR50 (2)
1989 VFR750R RC30
1984 GPZ750 Turbo
1984 RZ500 Hybrid
1986 RG500 Walter Wolf
1986 RG500 Skoal Bandit
1984 RZ350
1984 RZ350 Hybrid
1981 RD350LC
1981 RD350LC Hybrid
2009 CR500AF Supermoto 250X
2007 CR500AF 250X
1988 YSR50 (2)
1989 VFR750R RC30
1984 GPZ750 Turbo
Re: YZ85 reed valves.....are they worth the effort?
Are they worth the effort in grinding intake area to make them fit?
I'd be surprised if anyone has done this mod with stock carbs. I'm sure it would offer some gains, but the more air you feed the reeds the more gains you'll see from the reeds.
I'd be surprised if anyone has done this mod with stock carbs. I'm sure it would offer some gains, but the more air you feed the reeds the more gains you'll see from the reeds.
Re: YZ85 reed valves.....are they worth the effort?
Talking about the difference between a RGV reed and a RZV reed....
I guess this is why the RGV VJ21 was the first production bike to make 200HP per liter...with 34 Mikuni's
And as far as stock carbs go....has anyone bored out the 26 Mikuni's to anything larger?
Would a 28 bore be possible?
Seems an easier route than completely different carbs/cables/airbox....?
I guess this is why the RGV VJ21 was the first production bike to make 200HP per liter...with 34 Mikuni's
And as far as stock carbs go....has anyone bored out the 26 Mikuni's to anything larger?
Would a 28 bore be possible?
Seems an easier route than completely different carbs/cables/airbox....?
78 GS1000E
80 KD80
82 Katana
84 RZ350
84 RZV500R
86 GSXR1100
86 1100 sportster
88 FZR1000
89 RGV250 VJ21 SP
90 RGV250 VJ22 SP
91 TZR250 3XV2 SP
96 RGV250 VJ23 T SP
99 RS250
02 Hayabusa
16 KTM 390 Duke
17 KTM 1290 Superduke GT
21 Aprilia RSV4 1100
80 KD80
82 Katana
84 RZ350
84 RZV500R
86 GSXR1100
86 1100 sportster
88 FZR1000
89 RGV250 VJ21 SP
90 RGV250 VJ22 SP
91 TZR250 3XV2 SP
96 RGV250 VJ23 T SP
99 RS250
02 Hayabusa
16 KTM 390 Duke
17 KTM 1290 Superduke GT
21 Aprilia RSV4 1100
Re: YZ85 reed valves.....are they worth the effort?
I looked into boring the stock carbs a while back. It can be done but from what I understand the bore has to be cut in an oval. If you just plow through with a bigger round hole air will get by the slides. Also from what I figured you could basically go up to the equivalent of 27.5 mm.
Shake "N" Bake!
Re: YZ85 reed valves.....are they worth the effort?
Yep, I looked into it years ago, It would have to be oval, Something to do with the slide, Its exactly the width of the carb (26mm) and no room to bore a genuine 28mm...
1985 RZv500
1984 RZ500 Hybrid
1986 RG500 Walter Wolf
1986 RG500 Skoal Bandit
1984 RZ350
1984 RZ350 Hybrid
1981 RD350LC
1981 RD350LC Hybrid
2009 CR500AF Supermoto 250X
2007 CR500AF 250X
1988 YSR50 (2)
1989 VFR750R RC30
1984 GPZ750 Turbo
1984 RZ500 Hybrid
1986 RG500 Walter Wolf
1986 RG500 Skoal Bandit
1984 RZ350
1984 RZ350 Hybrid
1981 RD350LC
1981 RD350LC Hybrid
2009 CR500AF Supermoto 250X
2007 CR500AF 250X
1988 YSR50 (2)
1989 VFR750R RC30
1984 GPZ750 Turbo
Re: YZ85 reed valves.....are they worth the effort?
there is a recommendation of Erlenbach Racing (see http://erlenbachracing.co/reedcages%20mods.htm)
I am doing this upgrade actually with my second bike for the race track. I am curious about the result.
I am doing this upgrade actually with my second bike for the race track. I am curious about the result.
Re: YZ85 reed valves.....are they worth the effort?
I picked up a YZ85 reed just to have a look
Cutting into the ports to make them fit is more invasive than I really want for this bike.
But what are the possibilities of cutting the center divider out of the RZV reed?
And the differences between the steel limiters for the reeds...?
Do fiber reed petals need a different contour to limit movement than the steel reed petals...?
Does the shape effect power delivery in a particular way?
Cutting into the ports to make them fit is more invasive than I really want for this bike.
But what are the possibilities of cutting the center divider out of the RZV reed?
And the differences between the steel limiters for the reeds...?
Do fiber reed petals need a different contour to limit movement than the steel reed petals...?
Does the shape effect power delivery in a particular way?
78 GS1000E
80 KD80
82 Katana
84 RZ350
84 RZV500R
86 GSXR1100
86 1100 sportster
88 FZR1000
89 RGV250 VJ21 SP
90 RGV250 VJ22 SP
91 TZR250 3XV2 SP
96 RGV250 VJ23 T SP
99 RS250
02 Hayabusa
16 KTM 390 Duke
17 KTM 1290 Superduke GT
21 Aprilia RSV4 1100
80 KD80
82 Katana
84 RZ350
84 RZV500R
86 GSXR1100
86 1100 sportster
88 FZR1000
89 RGV250 VJ21 SP
90 RGV250 VJ22 SP
91 TZR250 3XV2 SP
96 RGV250 VJ23 T SP
99 RS250
02 Hayabusa
16 KTM 390 Duke
17 KTM 1290 Superduke GT
21 Aprilia RSV4 1100
Re: YZ85 reed valves.....are they worth the effort?
Hi, I tried these out with YZ85 reed petals the rz500 has a Phase 1tune JL pipes And 28mm carbs, couldn't tell the difference
between these and TSI modified reeds.
Cheers Ron.
between these and TSI modified reeds.
Cheers Ron.
Re: YZ85 reed valves.....are they worth the effort?
I'm running TDR fiber reeds in TSI modified cages. This was a popular mod 15 years ago. I believe the reeds I'm using are actually designed and sold for the RD400.
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- Joined: Sat Feb 04, 2012 7:36 am
Re: YZ85 reed valves.....are they worth the effort?
Speak directly with Tony Doukas. I sent him my TZR reeds and gages and he was happy to help and discuss things.
Re: YZ85 reed valves.....are they worth the effort?
hi that cost a little bit but VForce V3 reed valves are a good solution with just a litlle griding. Is this the best Price/HP result ? Idon't know
Re: YZ85 reed valves.....are they worth the effort?
Has anyone here tried these valves, or has thoughts on what may be good or bad with them?
At this point, I am looking for minor improvements over the the original 35 year old reeds.
After I get the engine broke in to some degree and see how well it runs, I may then go to modified cages along with better reeds.
Looking for a simple upgrade, but no experience with this theory.
http://www.boyesen.com/product-segments ... &year=1022
At this point, I am looking for minor improvements over the the original 35 year old reeds.
After I get the engine broke in to some degree and see how well it runs, I may then go to modified cages along with better reeds.
Looking for a simple upgrade, but no experience with this theory.
http://www.boyesen.com/product-segments ... &year=1022
78 GS1000E
80 KD80
82 Katana
84 RZ350
84 RZV500R
86 GSXR1100
86 1100 sportster
88 FZR1000
89 RGV250 VJ21 SP
90 RGV250 VJ22 SP
91 TZR250 3XV2 SP
96 RGV250 VJ23 T SP
99 RS250
02 Hayabusa
16 KTM 390 Duke
17 KTM 1290 Superduke GT
21 Aprilia RSV4 1100
80 KD80
82 Katana
84 RZ350
84 RZV500R
86 GSXR1100
86 1100 sportster
88 FZR1000
89 RGV250 VJ21 SP
90 RGV250 VJ22 SP
91 TZR250 3XV2 SP
96 RGV250 VJ23 T SP
99 RS250
02 Hayabusa
16 KTM 390 Duke
17 KTM 1290 Superduke GT
21 Aprilia RSV4 1100
Re: YZ85 reed valves.....are they worth the effort?
Its considered by many that the dual stage reeds never open stage 2. What you feel is ok as the torque of the smaller reed opening as that opens no problem, but then it never realises its full top end potential as the intake is made smaller by the 2nd stage not opening.
Id love to see a back to back test of these against a full single reed petal and Im sure its been done, I do feel it shouldnt work, but one can never be sure without testing of course.
Id love to see a back to back test of these against a full single reed petal and Im sure its been done, I do feel it shouldnt work, but one can never be sure without testing of course.
www.2smoked.com
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD250LC '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid
Like Watches? www.PloProf.com & www.DeskDivers.com
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD250LC '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid
Like Watches? www.PloProf.com & www.DeskDivers.com
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- Posts: 3236
- Joined: Sat Feb 04, 2012 7:36 am
Re: YZ85 reed valves.....are they worth the effort?
I think dual stage should be avoided for the reason Jon gives. It has been tested over the years with more downside than upside. I also I think anything made by Boyesen should be avoided. There are better choices.
And consider this: the reed you need will depend on how you plan to use the engine. There is no one size fits all. Once you know your engine requirements you can choose the correct tension and material. The wrong choice will have consequences. I learned that when mine self destructed after 1 hour of use.
And consider this: the reed you need will depend on how you plan to use the engine. There is no one size fits all. Once you know your engine requirements you can choose the correct tension and material. The wrong choice will have consequences. I learned that when mine self destructed after 1 hour of use.