2009-2013 Yamaha Raptor 90 budget build
We picked this Raptor 90 up locally in need of some TLC and decided to use it as a "pit quad" for adult use. Upon diving into what was required to make this worthy of adult use we found there was not much information or aftermarket support as these units are only semi popular for GNCC and occasionally seen as an entry level MX youth ATV that has to be quickly abandoned once a kid becomes more serious due to serious lack of aftermarket support- so we documented a few modifications we did with mostly all of these parts available from us hopefully this can be some help to anyone looking to get their kid into racing without breaking the bank.
If interested in purchasing parts or further information on this build fee free to email us firstname.lastname@example.org
We added an Alba Racing Bumper and 1.5" Wheel spacers front and rear (machining required to wheel spacers) We also added 10" front wheels with 20x6-10 AMS Pactrax tires. We also updated the hood to the 2016+ style.
A KLX110 aftermarket rear shock was added to replace the blown stock shock. We also added a universal fit FMF Turbinecore2 silencer - we cut the stock muffler off and removed the diversion on the header and welded the holes shut.
A Mikuni TM24 Flat Slide Carburetor and Uni Pod Air Filter was added as well, this gets rid of the stock CV carb and increased throttle response.
We removed the stock handlebar switch as the choke was no longer needed. We then added this Fly Racing Kill Switch and used it as a starter button (mounts on any perch)
We also added ~ 6" of bar riser (solid and pivoting) with KX65 bend Fly Racing 1 1/8 Handlebars to accommodate adult riders. This also required longer front brake cables 2016+ cables do the trick but require drilling your brake backing plate (minor) . Because of going to the TM carb we also had to separate the throttle from the front brake lever. We purchased a dual cable lever on ebay that worked perfectly. We then swapped the throttle to a Honda thumb throttle and made a cable adapter to fit a 88-92 Suzuki LT250R throttle cable which worked perfectly with the increased bar height and flat slide carburetor.
Another important aspect was the clutching and ignition. We did no internal engine modifications, however these are highly restricted between the clutching and cdi. To remedy this we changed out the rollers in the front clutch to lighter sliding rollers. For the rear clutch we added 107MM Shoes with higher engagement springs. For the CDI we went with a Big Gun Programmable CDI Box.
This Raptor now performs well -in the woods it would be very competitive with its 2 stroke counterparts or a great entry level mini mx racer.