MCR YAMAHA 660 52 GRIZZLY
IN ITS DAY, THE YAMAHA GRIZZLY 660 WAS A CROWD FAVORITE AMONG SPORT UTILITY ENTHUSIASTS. IT WAS AN ALL-AROUND WORKHORSE THAT WAS SUPER RELIABLE, COMFORTABLE ENOUGH TO RIDE FOR HOURS, HANDLED DECENTLY AND COULD OUTRUN MOST OF THE COMPETITION.
Unfortunately for those loyal 660 Grizzly owners out there, that day ended in 2007. The 660 Grizzly’s dominance in the market was overstepped with the release of Yamaha’s fuel injected, 700 grizzly with power steering. Not only did Yamaha release a better handling Grizzly with more power; the rest of the OEM’s were busy dropping even bigger, and more high tech 4X4 ATV’s on the market as quickly as they could produce them.
The Yamaha 660 Grizzly utilized a semi lowtech 660cc engine that was derived from the Yamaha Raptor sport quad, and goes even further back to being used in an overseas model; the Yamaha dual-sport motorcycle in the early 90’s. While this engine has been around for quite a few years now, its five valve head was almost revolutionary in its day, and very capable of producing a pretty decent power curve. So what do you do if you already have and love your 660 Grizz, but really want to be on par with the newer, updated machines?
This was the question I was discussing with MCR Racing’s Mike Cafro a few months back. After a few cold ones and a few snide remarks, Mike claimed that he was going to update his “old” Grizz to better than new, and that it would be able to hang with any of the new machines. Mike has been building amazing BAJA and WORCS championship winning sport quads for many years. In typical racer style, just as our deadline was approaching, Mike came through with this completely updated, super functional Grizzly. Mike built this machine to out-handle the competition and here is how it went down.
The first thing the older Grizzly needed was to handle better than the new updated, power steering equipped models. In order to do that, Mike leaned on our good friend Doug Roll of Roll Design ATV Suspension for a few custom parts. Roll Design built a custom, super strong 4130 steering stem, complete with Roll’s ultratrick 17-4 cast stainless upper and black anodized billet aluminum anti-vibe bar mounts.
This trick stem accommodates the oversized, fatigue-reducing Fasst Company Flexx handlebar system and is way stouter than the usual generic, bigbar adapter method of mounting them. The Flexx bar system actually flexes in the plane of the suspension, like shocks in your handlebars. This Flexx bar relieves an amazing amount of vibration as well as shock from your forearms and shoulders, allowing the rider to ride longer and faster. Roll also built some incredible one-off, cast stainless foot pegs that are similar to sets of their sport pegs, complete with kick-ups and all. To further reduce shock and fatigue, and compete with the power steering equipped newer units, Cafro called on Precision-RP for the very best steering damper that money can buy. The Precision Stabilizer works amazing on the Grizzly.
This is most likely because it is designed for an ATV, and not a motorcycle retrofit like most of the other steering dampers on the market. The Precision Damper absorbs bone jarring impacts from trail obstacles such as rocks, tree roots, and ruts like you can’t even believe. Today’s current power steering systems also do a great job of limiting negative feedback to the handlebar, but the bottom line is; if you ride your non power steering equipped utility quad aggressively, a steering stabilizer will most likely benefit you more than any other product. Mike then called on his longtime sponsor, Elka Suspension for a set of fully adjustable Elite Series shocks to make this big utility quad handle the rough stuff better than most sport quads.
Elite shocks are valved specifically for the type of riding that Mike will be putting the Grizzly through, yet the multitude of available adjustments including high and low speed compression, rebound, preload and ride height allow for simple adjustments that will perform in any condition. Mike rides his Grizz purely in CA, so it sees a lot more desert and mountainous conditions than it will ever see of mud, and this made his tire choice much easier.
The Maxxis 4 Speed tires are a very tough, yet lightweight utility tire that uses their proven Razr sport quad tread pattern to provide excellent traction in drier terrain; whether it be hard packed trails or ripping up a sand wash. This radial tire provides reduced steering effort and excellent bump absorption.
These tires were mounted on DWT’s new Sector three piece modular beadlock wheel. The Sector is a stylish, yet super strong heat treated wheel that is available in 12” or 14”, with a number of possible offsets to provide optimum handling in any situation. Definitely the trickiest thing about Mike’s tire set up is that he will never be stranded with a flat. Mike used the same BAJA and WORCS proven, run flat technology that has helped him win time and time again, south of the border.
Tireballs were installed at all 4 corners. This system fills your tires with multiple individual air bladders, or cells instead of just air. When a flat is acquired, it takes out one of 15 tire balls within the tire, and instead of riding home on a rim; you only lose the equivalent of about 7% of your air pressure. While this may seem a little extreme for your average utility quad; if you ride your vehicle way out into the back country, it’s nice to know that you will have the tires left to ride it back after you’re done.
Once the 660 was handling as good as, or maybe better than the competition, the next thing it needed to be competitive was a boost in the horsepower department. For any of the 660 Yamahas, whether it is the Grizzly, Rhino or a Raptor, a 686 big bore kit is the most cost effective and reliable way to boost horsepower. The L.A. Sleeve 686 kit consists of a 102mm LAPC box forged 11:1 piston, L.A. Sleeve gasket kit and a bore job. The 686cc kit is very simple yet effective, bumping overall HP as well as a big improvement off the bottom end.
Coupling the 686 kit with a free flowing Swamp Series HMF exhaust system and a high flowing, serviceable K&N air filter turns the 660 Grizzly into a whole new animal. The modified Grizzly will lift the front end at will and accelerates with authority. Extra horsepower is especially noticeable when climbing hills on the now slightly heavier machine. The stock Grizzly protection was upgraded with a very solid Warn bumper and a complete set of HD Aluminum skid plates from Ricochet Offroad to protect the undercarriage. I did not witness the installation, but Cafro specifically mentioned that they mounted to the Grizzly like a dream. It’s not very often that we receive an extensive set of heavy duty skid plates like these that are not a complete nightmare to install.
The seven year old, wimpy stock seat cover was replaced with a hand sewn, super durable Quadtech ATV one, just like MCR uses on their pro level race bikes. While the project was definitely centered around performance and handling, Mike being a lover of the outdoors, plans on taking his Grizzly on deep back country trips to fish and camp. To provide the most useable storage for accessories, OGIO ATV rack bags were installed front and rear.
The insulated, waterproof bags will hold just about anything, with over 4400 cubic inches of capacity in the rear and 2500 in the front. Sometimes there is just a little too much riding to be done, in order to finish before the sun goes down. This is why Ricky Stator HID replacement lights are used. These replacement bulbs and lightweight ballasts mount in minutes and really throw out the light. The HID upgrade puts out three times the light, all while drawing less wattage than the stock set up, leaving plenty of power for the Warn RT2500 winch.
The RT2500 winch is a very reliable winch with plenty of pulling power for many odd jobs, or even the next time Mike might miss a turn and needs to winch himself back up a cliff or out of a river. The Warn RT2500 even has a patent-pending brake system to hold the machine on a steep incline.
Did he succeed? I would have to say yes. The new Grizzly is as fast as most of the big bore, newer machines. It handles great when driven aggressively or just cruising, and should still prove to be very reliable. On one side of the coin, buying everything to replicate the MCR Grizzly would cost much more than a new machine.
On the other hand, a custom ATV is truly like a piece of art, and tough to place a value on. Any of these upgrades will help you improve the performance and ride-ability of your machine. It’s up to you as to just how far you need to go to be content.