Reed Stop notchers beware

riverman

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Feb 1, 2004
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One 98 and one 99 700 vmax's, one with 5000 and the other with 6000, can bored, needles dropped, and one with one layer head gasket removed. The sled with 6000 miles went 543 miles before a stopper broke and took out a cylinder. No big deal other than the cost of a cylinder since I was going to rebuild the top end anyway, but when I got into it, found three more stoppers cracked at the bottom. Took the stoppers out of my buddies 99 yesterday and after only 465 mile he had two stoppers cracked and the stoppers cracked were not the ones that were notched. No hard cold backfires on either sleds. I dont know if this is just age fatigue, more pressure on the stoppers with the can bored, or just a fluke, but we have ordered the new stainless steel stoppers to put in. If you have done this mod on a older sled you may want to take a look. Being towed in 45 miles by a f6 on a 5 degree day with 10 inches of fresh snow was NO FUN!!!!!!

ps We meticulously maintain these two sled, both get rode hard off trail, they still look like new, and have never had any mechanical failures untill now. :yam:
 

It not the notch that does it. I believe it's the backfire when it's new. This is my reed stoppers at 2500 miles when I pulled them out to notch them. Three of the 6 had to be replaced. Doug
 

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Yep, that's what we are seeing. If that stopper pictured was the one notched it wouldn't take much more vibration before it broke off and was chewed up by the piston. We were told today the stainless steel stoppers are running two to three weeks behind and are being shipped from Japan. Both our sleds are back together with used stoppers, but we will feel alot more confident when we get the harder stoppers in. As luck would have it, we leave this weekend on a ten day stay in Big Bay, MI. I sure hope they stay together with the abuse we are going to give them.
 
I was wondering if someone could clarify the reed stopper problem for me:

-Is the breakage only seen with the notched ones?
-What year and cc sleds would be affected?

I'm worried about them because I have a 00 SXR700 pushing 10,000 miles, my buddy has the same sled but with less miles, and another buddy has a 00 SXR 600. None of them have been notched.
 
My buddies and mine reeds were fine, no visable cracks, when we notched them carefully to the specs. We also bored the cans at the time. Like I said we didnt get many mile on before they started cracking. Maybe it's age, maybe its a combination of things, but I look at this way. If there wasnt a problem with the originals, why is Yamaha making them out of stainless steel now? Doesnt take that long to take a look anf be sure Doug.
 
I am confused... Are you saying I should pull my reeds? I have them out once a week or every other week when I clean the sled. I have put 3000 miles on since I did the stopper mod and mine are fine. Remember, the photo above was mine when I did the notch. I replaced my stoppers under warranty with the SS ones. Mine are fine, if you were questioning the state of my stoppers. Doug
 
NY_SXR700 said:
I am confused... Are you saying I should pull my reeds? I have them out once a week or every other week when I clean the sled. I have put 3000 miles on since I did the stopper mod and mine are fine. Remember, the photo above was mine when I did the notch. I replaced my stoppers under warranty with the SS ones. Mine are fine, if you were questioning the state of my stoppers. Doug


You take your carb rack and intakes off every other week to CLEAN your sled?!?!?! Holy Fauk!!!! :shock: I thought I was anal about keeping my sled clean 8) 8) 8)
 
I have heard of bad stoppers from stock without the notch...the notch will weaken a bad stopper and cause problems. If the stoppers are good you will never have any problems. The new SS stoppers are the best by far. I have been doing this for several years with no failures and only in the past year have I heard of this problem. Look...there are risks to any mod....I would do them on every sled I have ....I would not worry but ...its one bad incident that can cause the controversy. If you don't want to take the risk remove them and use the spacers, shim you motor to prevent the steering column from rubbing through the float bowls.....my 2 cents.
 
I have been warning guys about this problem on here for about 2-3 years. Buy a set of spacers. Most guys don,t have a problem..but ..the few that do cost huge $$$ to repair a cylinder, piston & head!
 
I just bought a stock 1997 sx 700 with 2400 miles. Can somone please give me the part numbers or brands of spacers that I should buy. Not quite sure if I need them but I just want to be safe. Thanks, iceracer :WayCool:
 
They are just 1/4" spacers made from aluminum or plastic. They are all mostly the same. You will need also the longer bolts and an extra set of gaskets. When you buy a kit it usually comes with everything you need.
 
I use both..with spacers you can use a smaller notch. Lots of miles..lots of backfires...no problems. If you are scared do what Turk says...some of us stock spare cylinder (for jetting experiments).
 
lol, i wish i could keep a good stock of sled parts, but that is a little expensive for a college boy. ;):D
 
Over 2k miles on spacers with no problems - but you can bet your arse that I will be checkin them this spring! By looks of the crack, it is definitly a fatigue crack as it propigates from the straight to radius transition. Could be a micro edge there that causes that - that would not show up on every sled. All it takes is a minor edge in that area from where it was machined!

Da Fin ;)!
 
Do the spacers take the pressure off the reed cages? I'm assuming that they lesson the vibration? ;)!
 


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