rx1007
New member
Ok. Here it goes. I know this has probably been addressed a million times. So here is one more. I am in the process of rebuilding a 700 sxr. All of the usual things, studs, new bearings, sliders, suspension bushings, etc.. My question is this: What can I do to build an ultimate sleeper? I would like to keep the stock muffler, and have heard about modifying that? Is there a detailed description on what to do? I am not opposed to thin gaskets, cutting the head, cylinders, porting, clutching(weights,springs,helix), jetting, reeds, gearing, etc. I am basically willing to do whatever it takes to make this the best it can be. Yes.. i'm trying to pull a fast one on my buddies. I realize there will always be some fine tuning with these types of modifications. I only ask for your recommendations from those of you who have played with these sleds. Any and all help is greatly appreciated.
Thin head gasket, bore silencer, notch read stoppers, you can add a boost bottle and change the intake boots.. port and polish motor.
Tunnel port the upper case wakes them up. It's hard to add a lot of power with the single pipe.
rx1007
New member
Great thank you! Are there any details showing the muffler and reed notch mods?
click on the ty tec pages link and snowmobile tec. there are how to guides for all of the mods other than the porting that where suggested.
Yamitriple
Member
A port job will not do much without pipes to match for the price of porting. But the 3 big ones always talked about wake them up nice. Stopper notch head gasket and silencer bore. I also bore 3 1 inch holes in the air box baffle inside the box. I leave the top of box alone.
Air box did nothing for.. just made me jet the crap out of it to compensate for the air with little to know change. But thats me.
rx1007
New member
Where do I find the exhaust muffler mod? If I install V- Force reeds, will I need to notch ? If I keep stock reeds with reed spacers, I shouldn't need to notch correct?
dont install the reeds, I think they are a waste. I already gave you the links to the Tech pages.. at least go and look.
here are the direct links.
https://totallyamaha.com/snowmobiles/aaTECH/silencer_boring.htm
https://totallyamaha.com/snowmobiles/aaTECH/ReedNotch/Reed_Notch.htm
https://totallyamaha.com/snowmobiles/aaTECH/sxheadgasketmod.htm
Yamitriple
Member
I didnt have to adjust jetting with the 3 holes just in the center shelf. Left the top alone, I doubt it adds little maybe even nothing. But it was easy and I figured why not. Aslo this was on an already stock jetted sxr 700. So it was rich to begin with
rx1007
New member
Thank you everyone. Mr. Sled, Thank you! I knew those threads would be helpful. I did see the links but didn't dig deep enough. Photos and directions are so much help. I will dig a little deeper into the clutching and jetting as well. I love this site and really appreciate all of the members who make it what it is. The best!!
If you are not worried about top end speed gearing is a great way to get a jump on your buddy's as well, I run a 21 tooth top gear with a stock 40 bottom gear.
Maybe consider a digital temp guage to monitor engine temps. Whenever the engine temps rise above ideal temperature, you are losing power.
rx1007
New member
Thank you all for your responses. I’m going to do the head gasket, install the reed spacers, regear the top gear, And do the muffler mod. I noticed no one mentions anything about any clutching changes with these mods? I’m assuming these are all done with the stock springs, weights and helix settings? As well as stock jetting. 0-2000’ elevation. Thank you all again!! Happy Holidays!
Yamitriple
Member
Jetting is fine stock but some run 142.5 across all three to get a little more power. Clutching will definitely have to change. There is a setup in the tech section with those mods. Its stock weights (not sure what weight rivets) with stocks springs and a 51/43 helix. I would definitely run a multi angle helix. The 51/43 is a good angle. You will have to add weight your primary weights to get your rpm back down to 8400
Yamitriple
Member
I'd look on FB market place for a set of triple pipes. All brands are good, just avoid the center dump power inc. Been there done that lol. End dump power incs tho would be fine
Yamitriple
Member
Actually if your re gearing I'm not sure if you'll have to add or take away weight lol I still dont fully understand gearing. With the mods and the gearing you will 100% have to reclutch it tho for your setup