This valve spring for the Arctic Cat 120cc is the best available anywhere. If you are not required to run a rev-limiter, you can expect to see up to 500 rpm or more increases over the next best competitor's springs. If you are required to run a rev-limiter, it makes this spring even more critical because you want to be the first to get out front and then hold off the pack.
These springs are custom made and designed to vastly improve low to midrange torque and a higher top end rpm. Due to the manufacturing process these springs last much longer than any other on the market. While competitor's springs lose greater than 9% of their strength in the first heat cycle and then 2% each heat cycle after that, these OBDi exclusive springs lose approximately 3% on the first heat cycle and less than 0.4% each cycle after that. After 12 heat cycles our springs have still not lost as much strength and performance as our competitor's after their first heat cycle.
0694-036-G6 | $9.00 per pair
Suzuki OEM Valve Spring, each
These valve springs are direct from Arctic Cat. Only if your club requires OEM springs should you consider these. These springs are not even close to the performance level of the Gen6 valve spring above.
0694-036 | $7.95 each
Suzuki Valve Spring Retainer
0693-313 | $9.95 each
Suzuki Cotter Valve
These are wedged pie shaped retainers that fit within the valve spring retainer, fasten to the valve stem, and hold the valve springs into the head. There are two required per valve retainer and four total for each head.
As of the 2014/15 season, rev-limiters are now required to be used on all stock 120 class races. These KOSO rev-limiters restrict the maximum RPM to 6850 and are the only ISR approved rev-limiter devices.
This rev-limiter uses a 9 volt battery for power so there is no power required from the snowmobile itself.
A very simple three wire hook up to install.
There is a rev-limiter for the 1999 to 2009 Arctic Cat 120 with the Suzuki engine and a different rev-limiter for the 2010 and later Arctic Cat and Yamaha 120 with the Yamaha engine.
This kit is an absolute must have to run in any stock class race in order to compete.
The Yamaha engines were made for longevity, not performance. Therefore, Arctic Cat created a kit that would allow the Yamaha engine to run equal to the Arctic Cat 120 with Suzuki engine and the Polaris 120 in stock classes.
The kit includes a high performance camshaft, valve springs, carburetor jetting, offset flywheel key, and gaskets.
This meter can be easily install on about any engines. Just wrap the RPM signal wire around your spark plug wire, set the number of cylinders… that’s it, you’re ready to go!
Memory recall of highest RPM since last reset!
Display range : 0~15,000 RPM
Display speed : <0.5 second
RPM input pulse : 0.5,1,1.5,2,2.5,3,4,5,6
Battery type : CR 2032
Battery life : 1000 Hours
Size : Width = 2.4" x Length = 1.3" x Height = 0.6"
Click Picture to Enlarge
120s typically come with 47.5 or 50 pilot jet. The pilot jets control how much air is allowed into the carburetor to mix with the fuel, thus creating a fuel to air ratio. In order to allow more fuel into the engine, you need to increase the pilot jet size first. Then you'll be able to increase your main jet size (or if using an adjustable main jet you'll be able to increase fuel flow) to match the fuel to air ratio and thus get more fuel into the cylinder.
Olson Brothers Dist is working on a new adjustable main jet for 2016/17 season and will post more information in the fall. For right now, we only carry in stock adjustable main jets for the Arctic Cat Suzuki engine.