sxr grass drag help

S

sxr_700

New member
Joined
Oct 31, 2004
Messages
85
I'm goin to take my 01 sxr 700 to the wausau grass drags and runnin in the 700 stock class I'm planning to do the head mod gasket trick, notch reeds,
no airbox or k&n's, loosen limiter strap, and I was wondering what kind of clutching and gearing should I do?
 
No offense, but with the F7's out there you won't stand a chance. Also if you would get anywhere the head gasket mod, notched reeds, and no air box or k&N's would get you kicked out immediately.
 
first of all I'm not looking to take first, just have some fun in the summer

and the people who run the wausau grass drags said you can take off your airbox, they wouldn't know about the notched reeds or head gasket, I was looking for some clutching and gearing help, not to be lectured.
 
You can remove the air box, but you must run air filters of some sort, you're first post said "no air box or k&n's".

First thing make sure you have a tether cord and straps going from the tunnel to your rear snow flap so the flap can't get sucked in.

Your gearing will need to be around 19/41. For the rear skid I suggest getting a set of SRX shocks as well as a set of 98-99 SX/SRX limiter straps because you want the ride height as low as it will possibly go. Crank the front spring on the front shock in the rear skid to the max and tighten your limiter straps so they are snug when you're sitting on the sled. For the rear shock in the rear skid you will want to set it in the "stiff" setting on the FRA and loosen the shock up so there is only 3/4'' of threads showing behind the lock collar. Also you will want to get a nylon strap and strap the rear skid down so there is only 2'' of travel. You can do that by going over the top rear shaft in the center beneath the shock and down to the lower shaft where wheels are mounted. In the front you will want to loosen the shocks so there is only enough pressure to maintain 2'' of travel and then get some nylon straps or chain to keep it at that height. I also hope you have a 1/2'' lug race track and some extra wheels added to the skid with the hyfax removed.

If you think you'll make it through tech then you might as well bore the silencer too because it does pick up a couple of HP and you're going to need all you can get. If you want to go further throw a 2* timing key in it as well. Just make sure you run premium fuel in it.

As for clutching, too many other variables to give you a exact setup because if you don't lower the sled, have a race track, have the exact gearing, etc. It won't work the way it should.

I wasn't trying to lecture you. I was simply telling the truth. There isn't a "trail stock" class at the Wausau grass drags, it's called semi-pro and most of those guys can run at the same level as the pros and do well. I'm just telling you not to expect much out of your SXr 700.
 
sxr-700:

srxspec is the fastest of us on the grass without a doubt, you should listen to whatever advice he gives you.

however you should realize that certain stuff you are doing here wont pass tech if they check, the head gasket and read notches won't pass, realistically the odds of them measuring the head gasket isn't that high, but the reed notches, if they tear you down that far they're sure to find. I've never seen them check for boring in a silencer, so you're probably ok there, but it's technically illegal. the SRX shocks is abit of a grey area from what I know, but it's something they're pretty likely to notice.

if you have adjustable transfer rods on the sled you'll have to take 'em off or you'll be DQ'd forsure.

you're also gonna wanna chain down the front end to it's minimum 2" of travel, the way I usually do this is with actual chain, sink the top shock mount bolt thru a link then snug it back down (with a washer on either side), now loosen the shock off as far as you can (till the spring is floating) get a helper to sit on the front bumper to compress it down to the bottom, then let the front bumper lift 2" this is the height you want, now I usually use the top radius rod bolt for the bottom end of the chains. go to the closest link to 2" but err on the side of caution with alittle more than 2" of travel.


now tighten the shocks back up, I usually set up a block of wood under the front bumper that's at the "bottom" of the stroke, then keep tightening until my helper and I can't make it hit the block by bouncing on the sled, then back it off until we just barely can.

you HAVE to be sure that you can demonstrate to the tech guy that the sled has 2" of travel both front and rear, so make sure that you'll be able to duplicate this bottoming procedure infront of the tech guy if necessary.

if you have them available I'd make sure you have a 19 and 20 tooth top sprockets, and 40-41-42 bottom tooth sprockets, between those 5 you have enough combinations you should be able to set-up for about any track.

to check if you're gearing is right you mark the clutches with a magic marker, then make your pass, be sure to shut down right at 500', don't hang onto it for an extra 30' after the finish line in testing. the marker should be completely rubbed off, or more likely your clutches can't make full shift and it'll be about 1/4" of marker left on the very top of the clutch.

as far as clutching goes I don't have my notebook here, so I can't help ya, I have a set-up somewhere for an SX700, should be pretty close, but I'll warn ya now that altho that SX700 would beat vipers, it wouldn't beat F7's, and that's a couple years ago when they where brand new, they sure havent' gotten any slower.

if memory serves, with the head gasket squished down that motor should rev about 8800rpm, you're gonna wanna engage at 5500rpm (since that's the maximum allowed) I usually swing my tach so that 5500rpm is just a hair above left, usually 5300 or so is left, that's where I hold the RPM at waiting for the light, makes it easier to watch with the corner of your eye, since your concentration should be on cutting a good light first, and on holding RPM second, but if you clutch bump you're screwed, and I don't believe in holding the brake since with a hydraulic braking system you'll be 10' down the track before it's fully let off.

you should also ALWAYS burp the sled on the line before you launch, to get the secondary completely back to an unshifted state, if you drive to the line and hit the brakes to stop the sled the secondary won't be completely closed, it's like launching the sled in second gear, it's just gonna slow you down, and if you're testing it adds another variable, which is the LAST thing you want.

I'll give my dad a shout and get him to check in my notebook for that set-up, hope this info helps ya man, but I think you're better off running backyard races, unsanctioned stuff. it takes a SERIOS investment of both time and money to be competative on an official circuit, for those guys that say "drag racing takes no talent" I challenge them to go out to an official event and run within 10mph in 500' of the fastest sleds in there class.

cheers
-Iain
 
you're also gonna want a camoplast 9811 track and 200ish chisels, the pattern is your call but I'd recommend atleast 4/bar, on a stock track you wont be competative. this might throw a hamper on that set-up I have to since it was not set-up for a race track, hopefully will give you a starting point tho.

again, not trying to lecture you, your money, your time, I'll help you out where I can nomatter what you do, but this is a fool's errand
 
Srxspec said:
No offense, but with the F7's out there you won't stand a chance. Also if you would get anywhere the head gasket mod, notched reeds, and no air box or k&N's would get you kicked out immediately.
Click to expand...
So there is nothing to run with the cats? That is it done deal?
 
19/41 gearing, 8ab weights,50/44 helix,green secondary spring at 80 degree wrap, suck up the limiters. You want to launch the sled & come out at about 8200 rpm & peak at 84-8500 rpm at the finish line
 
Turk said:
19/41 gearing, 8ab weights,50/44 helix,green secondary spring at 80 degree wrap, suck up the limiters. You want to launch the sled & come out at about 8200 rpm & peak at 84-8500 rpm at the finish line
Click to expand...

off the top of the head that sounds damned close...
 
tornado took out a tree at dads place so I was over there today, but my notebook is wrecked from water damage, one window was open in the roof of the shop and there was water everywhere. Sorry man, but that set-up looks like its gone
 
Junior said:
not if we play by the rules....
Click to expand...




president of our association told us a few years back at the drivers meeting that if were going to cheat, atleast do a good job of it. They do tech after the race but just check the CC and obvious things. I would not run that SXR 700 in a big race with all the big wigs that travel all over. I think you woud have more public embarrassment than fun. Those SX and SXR V-max 600 and 700 non power valved motors simply cannot compete with the SRX and not to mention the F-7. You can still be competitive with your sled only at a place where its non sanctioned such as a snowmobile club race or charity race aka back yard race for a little cash maybe a trophy. I would get that set-up that turk gave you. If your going to race it i would write that set-up down in your bible
 
Last edited:
yea i forgot they check the fuel and cc thats it. friend of mine told me that at a snowmobile club one race he has only seen 1 motor torn down in the last 5 years because somebody expected he was running a big bore... at my santioned race they just checked my cc's and the fuel in stock class after the race. i see very very few yamaha mtn sleds out here.
 
well there's ALOT of stuff you can do that'll get past THAT loose a tech, namely port and head work, I'd hit the porting with miriatic acid when I was done tho, to make it look like casting, if they open it up and see grinder marks you'll be in shit.

I'd cut the head(s) down abunch, get it to 150ish PSI, less than that if you're running very aggresive port timing.

you could go aftermarket reed petals to, don't go Vforce's 'cause if you go with a whole assembly it'll be visible from the outside.

you could also bore your carbs out a mm or 2, aslong as you polish them once you're done to cover the cutter marks.

if you do cut down your head(s), be carefull how you do it, if you just mill them normally you'll leave swirly's and be busted, do it either on a lathe (sounds yikes, but it's doable) or with a flycutter.

could go with a set of wiseco pistons to get abit of weight out of the rotating assembly, and you can true and weld the crank.
 
what does true and welding the crank do? only thought that 98-99 had issues. i have a 2002 motor in the sled and it seems bulletproof
 
balances it and strengthens it, any 2-stroke that's getting any work done to it should be trued and welded, infact that's one advantage to the 98-99's in my opinion, 'cause most dealers that also do performance work did a better job of trueing them than yamaha does.
 
You must log in or register to reply here.


Back
Top