686 Big Bore Results

[MrSled]

Chasis Dyno Results:
Run 009 with 26 HP to start w/ Stock Filter a HMF pipe
Run 044 33.6HP with mods below with HMF Pipe and open box lid
Run 024 33 HP is with my modded lid and I have made more changes but this gives you an idea.

I will try and get a stock number of a Grizz and my final numbers with tuning.


Radar Run Test Results:
Distance .4 miles
Radar Gun: Stalker Professional

Bone Stock Grizzly/Stock Tires
Speedo Shows 66 mph
Actual Radar Speed 61.4 mph

686 Big Bore Grizzly
Raptor Cam/Valves Springs
Modded Air box w/proper Jetting and Modded carburetor Lift Spring
Secondary Spacer/Machined Clutches
Wet Clutch Spring Change from EPI kit along with the EPI Blue Sec Spring
Stock Rollers
2" bored exhaust with HMF end cap.
Stock Filter

Big Bore w/Stock 25 Tires:
Speedo Shows 72 mph
Actual Radar Speed: 66.4

Big Bore w/26" ITP Mud Lites/Billet Alum Rims:
Speedo Shows 65mph
Actual Speed: 64.6
Note: The Speedo difference is much closer with 26" tires verse 25" stockers.

The 1.8 mph difference in top speed from the big bore tire change may be able to be overcome with more RPM on the bottom end by holding the shift back longer with the clutches. Note: Our Big Bore Grizzly does have fender flares and a 25 lb winch; therefore we feel just shedding those items could make a few more mph. Remember weight and wind resistance are enormous factors. Considering this, in my opinion, the gains that have been made are huge!!!!

Stock Verse Big Bore in a race:
The Big Bore will pull a wheelie (10"-12" from ground) from a dead start to 10-15 ft(25" Tires) 6-8 ft (26" Tires) out and launch ahead of the stocker by 1 or 2 ATVs and continually pull away up to 15 ATVs on top end with either the 25" or 26" tires. As the results above have shown, the tire change will decrease your top speed slightly but with 25" tires your 0 to 60-speed distance is shortened with greater acceleration. It's really quite unreal the hp and torque you feel from this modded machine....

At this point I am very very pleased with the results we have accomplished with Randy at All Season Repair and Joe at Rossier Engineering. My goal was to beat a stock machine with the bigger tires and be able to pull a wheelie with little to no effort. With help from Randy and Joe, we have accomplished both!!!

A few things to remember. A good running Rapter or YFZ will do 70-72 mph. And not all speedo will register the same compared to the gun.

Also attached is the Dyno Results prior to the final tuning!!!

 

[SledderSteve]

Excellent report and kudos to you and your team.

 

[MrSled]

Thanks Steve

 

[clutch]

Congradulations on the great numbers.

 

[Ganz]

Good post, If you don't mind me asking, how much does a 686 set up like that cost?

 

[MrSled]

If you want it right, like $1300 or $1400. Call Randy at allseasonsrepair.net and he will give you a quote. Make sure you tell him you want the exact same thing as I have posted on Totallyamaha. I may be a bit high on the price.

 

[Ganz]

Thanks buddy, I'm not there yet but down the road I may get the bug for more power.

 

[pro116]

big bore

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