From the September/October 2011 issue of ATV Rider Magazine
During this year with money growing tighter, instead of looking at new rides we had to take a serious look at what quads we had at home stuffed in the back of the garage. The fact that we have an ATV to ride is good enough, but having to bring it back to life can be a daunting task in itself. One particular quad caught our eye, and with just a few weekends of extra work we had one of the most popular utility ATVs ever in production back on the trails.
Our 2004 Yamaha Grizzly 660 had been through many years of use at the hands of its owner, and although it was given basic maintenance, it still looked tired and had plenty of things that had been broken and never repaired. Our first goal was to partially disassemble the beast and give the machine a very good cleaning. Using our proven cleaner, Super Clean, we began by simply spraying on the degreaser using our garden pump sprayer. Within just a few times of spraying and rinsing the Yamaha Grizzly looked 100 percent better than before. We never even had to touch the quad with our hands at all!
After the cleanup we wrote out a simple list of things we would address while trying to keep the expense down. The goal of this resurrection wasn’t to overaccessorize the Grizzly 660 but to add more practical things to bring it back to life. We knew we wanted to do something to freshen up the engine so it could handle a few more years of trail riding, and that’s when we found the performance kit by Wiseco. The Wiseco top end kit had a new higher-compression piston with valve reliefs in the dome, rings, valve stem seals and a full gasket kit for the overhaul. The piston kit comes in a higher compression than stock, bumping it up from the stock 9:1 ratio to 11:1. All of that just means fresh new power and lots of it. With the nice, clean engine disassembled we took the cylinder, new piston and rings to the machine shop for the new kit to be bored and properly fitted into our engine. When all was said and done on the engine assembly we changed out our old oil with some Motul ATV-specific lubricant and a new K&N Wrench-Off oil filter, which should make our Grizzly very happy.
Knowing the engine was going to be a bit stronger inside we had to get more air in the combustion chamber, so we turned to Quad Works. There are many parts to buy when properly tuning an engine and some companies are combining these parts into complete kits, and the guys at Quad Works just happened to have a Stage One power kit that would perfectly fit our needs. This kit included a K&N filter, Outerwears pre-filter and a complete Dynojet jetting kit. K&N filters are known for high-flow cotton gauze filters that catch the tiniest of particles, and when you throw on the Outerwears pre-filter you can almost guarantee that nothing unwanted is getting into our engine.
Since we had a slight increase with displacement with our new piston and new K&N air filter installed, we knew there have to be some changes in our jetting. More air with the same amount of fuel can cause a lean condition and fatally wound our Grizzly, and the Dynojet kit that came inside the Quad Works kit allowed us to properly tune the fuel mixture for the added air intake and performance motor modifications. The kit comes with a replacement needle as well as many jets to adjust the fuel supply for various elevations and modifications.
So we turned to the exhaust, and our stock silencer was beat so I figured the best decision would be to go with a new aftermarket slip-on system from Dubach Racing for our Grizzly overhaul. As we were trying to restore this machine on a budget, we opted not to install a full system, and the slip-on still gave us a significant power increase because the biggest gains are made with a free-flowing muffler. The aluminum body of this muffler is much lighter than the stock unit, 100 percent rebuildable and can be used with a quiet core to help ensure we meet the sound limits of any trail system we want to ride.
It has been pretty obvious that we’ve found a lack of maintenance in the Grizzly in the engine department, so we decided to dig a little deeper and tear into the machine’s drive system. Since we gave the top end a good refreshing, we wanted to ensure that the Ultramatic transmission could handle the fresh engine and more that we had in mind. While the transmission has always proven reliable with a stock machine, we were intending to run some larger tires so we opted to install an EPI clutch kit and belt that the company had recommended. Installing this kit was definitely time-consuming and, without the proper tools, could discourage the average weekend mechanic. Aside from the clutch kit, EPI also supplied us with a clutch spring compression tool which we highly recommend purchasing if you plan on doing this job yourself to avoid losing an eye to airborne high-tension clutch springs. With the clutch components changed out, we sealed up our cover to waterproof it as best as possible and were on to the next task.
The Grizzly, as you know, comes with handlebar-mounted electronic 4WD controls, and during a ride a few years ago one of the buttons was broken off, which made engaging the 4WD a bit difficult. Luckily, Yamaha has a huge inventory of stock parts that can be ordered through the local dealer. We couldn’t replace the button itself; instead we had to replace the switch set, which only required a Phillips-head screwdriver, making it the easiest job on the entire project. Once the new switch was in place we installed a new set of A3 Spider ATV grips in place of the worn-out OEM grips, which helped us control the beast in any weather.
The front end contained a few other items that we wanted to address, and one of those was the front bumper. The bumper was pretty bent up, but there weren’t a lot of choices when we were looking for replacements. We decided to contact SuperATV.com for a bolt-on bumper cover that would not only add a little better protection to the front end but also cover up the bent parts of the OEM crash bar. But when we removed the bumper we noticed a huge problem. There was no winch hiding in the frame. We had set a budget and swore to stand by it, but if a utility 4x4 ATV doesn’t have a winch, it’s just not right. Right? I went over to the local Harbor Freight Tools and picked up the newest product in its Badland winch line. This 3,000-pound winch comes with many of the features found on some of the most popular winch names in the industry. After the Badland winch was wired in and mounted to the framework, we put the new bumper cover on over the stock front bumper and, man, what a difference it all made. Keeping with the theme of providing great protection for our machine, we opted to go with all-aluminum skids from Ricochet. The skid plates are made of super-thick aluminum and are a perfect fit on our machine. With the surface they cover we don’t have to worry about bashing in the beast from the bottom up.
To get control of our restoration we installed a new gripper seat cover from Quad Works. We have used many of its covers over the years, and because of the superb fit, finish and ease of installation we just keep coming back. The more work we put into our project, the better it looked, but visually there was one thing keeping it a bit of an eyesore and that was the plastics. After years of riding they’ve gotten pretty scratched and show significant wear.
The plastics on any quad can be expensive. To have them painted or anything else is also quite expensive. Our Grizzly plastics were pretty scuffed and we had to keep our budget in mind, so we decided to try some Plastic Renew. The concept is that you clean, buff or sand and then gently scuff the plastics. Then you apply the chemical treatment to bring the shine back to the fenders. This seemed like a long process, but with the high cost of replacing them we opted to use the one thing we had a lot of, which was time. We were impressed with the amount of shine that we were able to get back, and only time will tell how easily the newness will wear off.
For our last few tricks we decided to look for new wheels and tires. The stockers were worn out, and we wanted a more aggressive overall looking and performance tire. Getting a bigger tire meant we had to raise the Grizzly a little, so in one fell swoop we installed a High Lifter 2-inch lift and made way for our MotoSport Alloys 14x7 Reaper wheels wrapped in the 28-inch High Lifter Outlaw radial tire. The Outlaw radial will give us the best all-around trail and mud tire for the Grizzly, while the MSA wheels will keep them looking awesome. This combo is on the higher end of our budget, but will give great performance and looks.
Overall, the 2004 Yamaha Grizzly looks better, runs better and will give us many more years of great service on the trail. The thing you have to focus on when doing a project like this is budget. Don’t let impulse buying get you into the cost of a new machine. We may have spent a bit more than expected, but in the end we think this machine is just as capable as any of the newer machines on the market with the bonus of upgraded parts and no annoying monthly payments. ATVR