Norwegian RMK 900

Ole Andre · Sep 9, 2011

Hi everyone!
I have been a member here for a year of so, done a lot of great reading, specially in the 900-section. My dad own a fusion 900 since 2006, i really like the torque and power in the bigblock polaris, so a coupple years a go i brought my own 900, only a rmk instead of a fusion. Got a cheap damaged 151" 900 with 230miles on it.
　
　
　
Modifications

Engine

- Ported engine, crankcase,cylinders and pistons /Compression 9.2bar
- Slp exsahaust
- Modded stock airbox
- probbaly more I can't figure right now
- New bearing and balanced crank

Drivetrain

- P-85 primary from a 600 "lightweight", black/pink sping, 74mtx weight maxed out(2steelrivets)
- stock team secondary
- 153" 2.25" track, 3.0" pitch 8 tooth drivers
- 19-39 gearing

Chassi

- removed front radiator and the cooler in front of the track, applied a larger rearcooler .
- Skinz airframe runningboard
- BOSS highrise seat for RAW
- Compfusion eniginemounts
- 09 plastic
- Homemade tunnel and cooler

Other

- Koso dual egt and air/fuel
- Boondocker controller
- rox adjustable riser and fly handlebar
- ++++

Suspension

- a arms from a 08 dragon rmk, stock spindels with floats w/ swaybar
- Stock skid
　
I could need some help for a better clutch setup, normally i run from 1000 to 3000' . After the assembly I only run the sled for 8 hours or something, try to break it proparly. Ritch fuel and oilsetting, but still i god a fairly high rmp, the max readings at the MFD was 8100rpm. I'm pretty sure the HP will increse significant when i run it leaner. Some advice? Heavier weights and probbarly a steeper hellix right?
I have been thinking to increase the ski distance to 43" and swap the floats with a firmer shocks, how mutch do it matter? here where I'm driving it quite difficult terrain, could need more stability. What do you guys think about this?

There are also some parts I'm looking for, so if anyone knows of any for sale at a reasonable price is to contact me on PM.

WTB: Fire&ice airbox, y pipe slp, spindels from 08 or newer,harder springs for the skid, 8 or 9" inch wheels and freedom axle,thumbwarmer.
　
Ole Andre, Norway

roni87 · Sep 9, 2011

900

Sweet! alot of work into that.

guidoxpress · Sep 15, 2011

that looks outstanding!!

great work bud, i love the tunnel, RAW hoop conversion, and the dedication...

keep it up and post more pics as you continue the work!!

thanks for sharing! (great write-up as well)

river · Sep 15, 2011

I have the ported slp kit and I run 78's in mine and still get 8100 rpm and slp says that's Ok. it run's great and pull real hard . hope that helps. some run better with lower rpm's and some don't .flatlander here.

guidoxpress · Sep 17, 2011

can you post some pics of your custom rear cooler and how you ran coolant to it? did you use the SKINZ running boards and modify the ends?

MORE PICS PLEASE, lol.

Ole Andre · Sep 17, 2011

thanks guys! My rear cooler is a simple cooler from a wildcat 91 with a little modification. Stock it around 7l coolant(?), now i have roughly 3l. My sled run at 120-130 farenheit, and so far i have now experiences with "overheating"..
Guido, i can take some pics when i'm home. I'm a student, so i'm not home all the time. I have used a fusion chassis, cause the original rmk chase is total messed up after a ugly crash last Easter. One of the coolant-line runs directly from the colantbottle trough the profile in the fusion tunell, the other line goes from the main outlet in the head, over the eninge to the other profile in the tunell and right back to the cooler. I really love the big vanamuburg cooler, but with the shippingcost and the norewegian tax made it to expensive. The wildcat cooler seems to do the same job.

Guidio: If you looking to adapt the coolingsystem i would recommend to use the tubes from a ac-m-serie if you have the rmk tunell(without the profile).That's was my first chosie before i found a cheap fusion chassis.

River: if you calulate the pistionspeed at 8100rpm it's a way to high, i really dont like that high speed due to the "weak" crank. When i ported the enigne i removed alot of the piston, and a little of the pistonsupport in the reed direction. I have used some stock 05 pistion(i know you guys don't like them at all, but i think them have more potential that the 06 or wiseco. I have removed around 60-80g of each piston, lager "port" and removed alot inside of the pistion. I spent around 100 hours just to modify the cylinder, piston and the crankcase, i cross my fingres, and hope the piston are strong enough. I would like to get a HTG can and pipe and lower the rpm to 7800rpm.
I'm a flatlander, so I will probably get a little more power than most of you guys, but i have done all the engine modification myself, it's hard to say if i will gain or lose power.

I have some question: i have used a boondocker controller, but i thinks it very difficult to tune the engine proparly. I have a little theory that the exhaustsensor parameter is a little low. Is't any of you guys that have tried to "adjust" the valuedue to change the resistance in the sensor? will i need to remove or add resistance to allow a higher exhaust temperature before the cfi kick with more fuel or setback the ignition ?

I consider to buy a team tied secondary, it's a great opportunity to get faster backshift and a better choice of helixs. Any opinions ?

I will post a little video of the beast before i do all the modification(that's all i have now, all the building pictures are gone cause a bad harddrive)

After my last posts I realize that my english is a little rusty, i can only get better, hope you fellows understand.

Thanks for a great forum, Ole