110 mph / 2000 CLUTCHING HELP TURK AND OTHERS

harness racer

harness racer

New member
Joined
Jan 9, 2008
Messages
541
Age
56
Location
Val Therese ont.
LOOKED BACK IN THE NBSSR ARCHIVES AND THE FASTEST I SEEN FOR THE 600 CC CLASS / 2000FT TRAIL CLASS. WAS 109MPH BY A FIII. IT WOULD BE AWSOME IF WE CAN BEAT THAT THIS WEEKEND WITH A SRX 600 , BUT THE CLUTCHING WILL HAVE TO BE SPOT ON .REDUCING DRIVER WEIGHT FROM MY SKINNY 220LBS ...OK 229LBS TO 115 LBS. IM A LITTLE WORRIED ABOUT AN OVER-REV ? DYNO'ED THE MOTOR AND IT MAKES POWER BETWEEN 8350 AND 8500RPM

600SRX
HERE IS WHAT I HAVE TRIED SO FAR , ANY SUGGESTIONS WOULD BE APPRECIATED...EVEN YOU MOD....LOL

#1 SET UP
PRIMARY
B]WEIGHTS[/B
89A10 BASE WEIGHT 48.5GR. ROLLERS 15.5 MM SPRING Y-W-Y 128KG
INNER EMPTY
OUTER 0.9 GR.
TOTAL 49.4 GR.

SECONDARY
8BV71 47DEGREE. YAMAHA GREEN DOT @60

GEARING 23-39

PLUGS BRP9ES AND NO AIR BOX FOAM LEAN MELTED THE PTO PISTON

FROM A ROLL 8400RPM AND CLIMBS TO 8600RPM 111.32MPH/2500FT. :nos:


2 HOURS LATER NEW PISTON

AIR BOX FOAM RE-INSTALLED
BR9ECS
A LITLLE WARMER ASWELL
EVERYTHING ELSE THE SAME

FROM A ROLL 7900 RPM CLIMBS TO 8300 RPM 103.04 /2500FT. :o|


#2 SET UP ROLLER ROOSTER
PRIMARY
8DN-10 BASEWEIGHT 41.7GR. ROLLERS 15.5MM SPRING W-W-W 119KG
INNER 4.5GR.
OUTER 2.3 GR.
TOTAL 48.5 GR.

SECONDARY
ROLLER ROOSTER HELIX 39-35 SPRING YAMAHA RED DOT @70

GEARING 23-39

PLUGS BR9ECS = LIGHT BROWN NOT TAN

FROM A ROLLING START 8800RPM AND SETTLES @8600RPM 106.2MPH/2000 :dunno:



]
 
Last edited:
put the red spring @ 60 deg w/roller rooster for better top mph.

try 8dn-20's or 8dn-00 for top speed.....try the y/w/y spring w/these weights.

sounds to me like you need a primary spring change w/the #2 setup to get a straight shift and maybe a weight change.
 
Last edited:
Green at 60 in the RR. that helix will shift 10 degrees higher on each end as compared to a regular helix.Red secondary spring does not have enuff tension in it for that helix on the 600 with those weights.Load the 89a-10,s lighter inner & heavier in the tip.
 
Fuel, jets size?
Your first run was 8400~8600 rpm.
Fix piston add foam and went to 7900~8300 rpm, that sounds like a big drop from just foam. Maybe down on power still, all the other pistons look good? Did it run that rpm before with the foam?

I'd go back to the first setup. No air box foam. Run 50/50 Prem fuel/100AVLL (or 100+ race fuel). Run the sled 1000' and check plugs, then 1500, then 2000'. Maybe bump the jet up on the PTO if thats the only lean cyl. Jet it to max power first, then gear, then clutch it. I'd start at 8300 then finish at 8600. From what I've seen, at peak mph a little over-rev pulls a tad more mph. In short you load the motor to get up mph quick, then lighten the load so rpm take over and shift out that last bit.
 
3/4" track w/ 96 new sharp trail studs. if you can't do the 3/4" track than @ least do the studs.
relax the front shock springs & tape the spring support plates so they don't fall out.
shorten the front limiter & back off the preload on the rear of rear shock & put pull bars in softest setting ( this will lower the sled ).
take all the transfer out of the control rods ( lock them out ).
put on a set of old worn ski wear bars.
check all suspension bearings.
align the front skis & square them to the track.
lower the handlebars so you can get under the winshield.
ask lise l. to run the sled for you - your to big.
8buoo empty ( this weight has a very high full shift force ).
ywy
your rollers are good.
stock secondary w/ 47* helix - 45* would also be good
red @ 30*
no foam in air box
run carb vent tubes into the air box.
i'm sure i missed a few things but this will get you close. you may have to grind a bit off the 8buoo's to get the shift correct. don't use race fuel. on the dyno w/ a stock motor it lowers h.p..
because the secondary is so soft you will need to roll out & ease into the gas for about 100' so you don't suck the belt.

bob
 
I like the 8bu,s with the 45 helix & a bit of tip weight...about .8 to help pull that weight thru the shift.
As an ex-owner of 2 600 srx,s & familiar with 8bu weights I don,t think the 47helix/red secondary at 30/8bu combo is gonna fly on a stock sled.
 
Is your entering stock trail class.check the rule's before you do all this changes too your suspension.GOOD Luck this weekend and i hope you show your yamay off and pull good number's.
 
paul:
all the suspension adjustments are legal as long as you don't tie it down. they do have rules....but no tech. lots of cheating going on. you've got people running IS class with pro stock sleds. eg.: bigger carbs & lightweight suspensions & chassis. a lot of the speeds would come down if there was tech inspection.

bob
 
Good Afternoon All We Just Got Back From The Race Track , It Was Not A Good Day To Test But It Was A Day Off So Its All Good !!!! Yamyrider Was With Me And He Was Down 300rpm And 6mph From Usual !!!

The Temp Was +5c / 41f Water And Slush On Track And A Head Wind To Boot!!

Tried As Many Suggestions As I Could,, Keep In Mind This Is My Trail Sled So We Rode There . If It Feeze's Overnight The Track Will Be Very Fast Early In The Morning .

First Trial Today (a)

8dn-10 = 49.8gr , 4.5 Inner , 4.2 Outer
W-w-w , 15.5 Rollers

R.rooster 39-35
Red Dot @60 =
102.3mph
Click to expand...
Br9iex
23-39 Geating

Note: 8600 Rpm And Was Decreasing To 8300@/2000ft.


Trial (b)

8dn-10 = 49.8 Gr , 4.5 Inner 4.2 Outer
W-w-w 15.5 Rollers

R.rooster 39-35
104.5mph
Click to expand...
Green Dot @60
Br9iex
23-39 Gearing

Note: 8100 And Climbs To 8400rpm @/2000ft.


Trial (c)

89a-10 =49.5 Gr. Inner Empty Outer 0.9gr.
W-w-w 15.5 Rollers

R.rooster 39-35
103.0 Mph
Click to expand...
Green Dot @60
Br9iex
23-39 Gearing

Note :7900 And Climbs To 8400rpm @2000 F.t Seems Very Sluggish In The Bottom Until Rpms Start To Climb Above 6500 Rpm


It Almost Seems Like I Have To Much Gear For That Distance Today 1.695 70l Chain
I Have A 40 T That Is Lighter Than My 39t But I Would Be @ 1.74 ? 70l
Would It Be Better With 21-35 / 1.66 66 L Chain ?

even If We Dont Beat 110 Tomorrow , I Wish You Could Have All Seen The 13 Year Old Boy's Smile Today It Will Be His Fist Time Radar Run And Im Sure Not Even The Super Bowl Trophy Will Be Better Than If We Win !!!

Thanx To All Who Replied And Also For Keeping This Thread CLean And Professional

Will Post Results Tomorrow And Look Forward For The Fine Tunning Help For Sunday
 
Last edited:
conditions were very crapy...sinking in slush as the day got hotter....there was a drop in rpm in the afternoon....my sxr best run was 110mph in just over 2000ft.
not sure what i am going to do for gearing...I am at 23/39...not sure if me and harness racer want to be wrenching till 1AM.
 
STOCK GEARING IN THE 00-01-02 700 SRX IS 23-38. THAT WAS A 1.65 RATIO. ON PAPER, IN A PERFECT WORLD THIS SLED WITH THAT RATIO IS GEARED FOR 110. THINK HOW FARR A DISTANCE IT WOULD TAKE TO REACH IT, UNDER PERFECT CONDITIONS, PERFECT CLUTCH EFFIENCEY, PERFECT DRIVELINE.
23-39 IS A 1.70 RATIO GIVES YA LESS TOP SPEED THAN 23-38. TO DO THE MATH, YOU GET THAT QUICKER WITH ALITTLE LESS TOP SPEED. 3:16 (yammie tony)
 
GOD!!!! what about using the 24:40 gear ratio then. Just a tad higher ratio(a fraction) and get less rolling resistance with the chain.I am thinking about setting that up next season myself.
 
with a 47 helix and and 8bu's and big gearing as BuffaloBob mentioned has big speeds on the 700 but never ran them on a 600.Some guys on here keep saying they dont's have top end use 8dn 00 or 8dn 20's but those are the guy that never tested week after week on radar.
 
Last edited:
Pics will be up later....we broke the NBSSR record with the 600srx in 2000ft....110.3MPH.
The SXR ran 116mph in 2000ft.....great day for both sleds!!!!!!!
 
You must log in or register to reply here.


Back
Top