reed notch question

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sxrextreme

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Nov 28, 2004
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ny (fingerlakes region)
i know this topic has been posted (but i have a few questions) im doing the air box mod and the reed notch to my sxr 600 my questions are as follows
1 how much horsepower does the sx600r put out before these mods and after the mods
2 will and can the reed cage break because after you notch it it seems thin near the sides where it tapers
3 i know i have to go up one jet size across the board with the air box mod but i have noticed that the jet sizes vary why is this 1/136.8 2&3/133.8 :rockon:
 

SX-R puts out 98 hp stock, as for the reed notch HP gain people have claimed 2-3hp and another 2-3 for thin head gasket. I currently have my SX600R tore apart in the garage doing all the "freebie" mods to it, installing a 121x1.25" ripsaw track, and dropping to a 19 tooth upper gear in the chain case. Clutching a SX600R helps ALOT, just clutching alone allows my 600 run ski to ski with my dads SX700R.

A 51/43 helix, 8AB wieghts with 2.4 gram rivit in the innerhole, and green secondary spring wrapped 60* is a very good starting point for clutching.
 
thanks blueironranger for the reply ....yeah im going to clutch it sometime here but right now im doing the freebies ...just got done notching my reeds and air box mod now i just have to go get some bigger jets and install everything....so i guess im looking at a 4-6 horsepower gain with these mods right so i should be putting out 102-104 horses ......i wonder what the noticable difference will be ;)!
 
About #2 in your post.

Just be careful when your machining the stopper. I left mine a bit taller in the side areas than the recommended. Basically I did not cut down as deep. Seems to really help.
 
thanks for all the replys guys i really appreciate it .....fuzzbutt youre too late i already did the notch ...and i did them to the specs on tech pages 24mm x 18mm x 4 mm .....and i wondered about how thin they are, i just wondered if the stopper could break due to vibration or heat where it is most thin (because if anything broke off that would not be good) but i tend to over analyse everything sometimes but i dont think it would really matter would it? and it would most likely crack.....but seems like no one has had a problem or im sure there would have been feedback.......now all i got to do is rejet... luckily i live 10 minutes from maximum performance ...so that rules..... :yam:
 
the jetting is not the same across the board because when yamaha was testing the engines they found the PTO cylinder ran hotter, thus it has a bigger main jet and needle jet to keep the temps more equal
 
I think that the notch on the reedstopper is a very strange thing to do.
I'm also worried about the strength on these part's when you cut away that much.

I'm also wondering over why the engineer's at Yamaha have'nt discovered that the reed-stopper blocks the intake and corrected it.
 
If you are worried about the notch and breaking the part then you can put the spacers. Not free but works just the same.
 
the reed stopper notch is an excellent modification that makes a very respectable improvement, and there have virtually been no reported failures after doing the mod. The stoppers aren't under a great deal of stress
 
this is a higher performance mod and is not dangerous to the machine if not done thats why Yamaha has not changed it. The thiner head gasket or clutching makes the machine perform better but Yamaha will not change the factory set up. Yamaha engineers their machines with a lot of head room.
 
Last night I had the reed's out and now I understand what the notch does.

How Yamaha can put in a reed-stopper that blocks one port is unbelivable.

I've read that I will get 2-3 hp by notching, has this been tested?

I've also read that the silencer mod will increase the horsepower by 5-7 hp,
has this been tested?
Or maybe the only thing that increase is the sound level?

Is there any danger for the engine to do this modifikations.
 
With identical clutching/outside snow conditions I picked up 150rpm with the thin head gasket and reed stopper notch, thats quite an improvement. I pickup of RPM's means the engine is making more power.
 
Try 400 RPM for mine. Did it with the 2 layer gasket and reed notch after breaking in new pistons. Stellar nearly free power. Also the down low power increased a bit which is a big bonus for a trail rider.
 
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