07 The jetting that really seems to make my low-compression 510 and the stock-piston 450 happy is a 182 main, stock OBDVR needle, fourth clip position, 55 pilot, diaphragm rod adjuster screw three turns out from all the way in for the 510 (four turns out from all the way in for the 450). The mixture screw two turns out. The leak jet standard (plugged). The starter jet is the standard 85. These adjustments are made keeping the following in mind: We used Cam 2 110-octane race gas mixed 50/50 with pump gas, and we ran a Twin Air foam filter, the stock header and the stock Husky optional (Arrow) muffler.
08 In the subframe are Riv-Nuts that provide the threads the side number plates screw into; these can spin if not seated correctly. They're installed and then squeezed against the inside of the square tubing with a tool that works sort of like a rivet tool. The installation tool should seat the knurled surface into the aluminum. If a bolt won't loosen inside one of these Riv-Nuts, remove it by using Vise Grips on the head of the bolt and then turning the bolt counterclockwise while putting a side load on it at the same time. Once removed you can use a Riv-Nut tool to seat the Riv-Nut better and correct the problem forever. K&L (www.klsupply.com) sells these tools, but they're very expensive; we found an inexpensive lesser-quality version at Harbor Freight (www.harborfreight.com). Your Husky dealer might have this tool and be willing to tighten up the inserts if you have it happen. It's a piece of cake if you have the tool. MSC (www.mscdirect.com) also sells this tool for $29 and those Riv-Nuts come in handy for other projects as well.
09 In the unlikely event that the left radiator gets bent forward, the radiator hose will come in contact with the header pipe which will burn a hole in the hose. We wrap the inside header pipe with exhaust header wrap and we used a thermo sleeve made by Thermo Tec that fits over the radiator hose in this location. We also bolt on aluminum radiator guards to strengthen and protect both radiators. In fact, we have not had to replace one radiator since we started using the guards manufactured by Flatland Racing. We do bend the rear mounting bracket to prevent sharp edges from contacting radiator fins. I haven't boiled over any radiators or seen the standard hoses fail, but we take the following preventive measures to our cooling system: install a 1.8 radiator cap, install high-temperature silicone hoses (CV4) and run Spectro coolant. We don't remove the standard coolant recovery bottle.
10 At the junction where the header goes into the muffler, I've seen people melt their riding pants and/or boots. When riding, my leg does not touch this area, but if you're standing or leaning against this spot when it's hot, you could melt your riding pants. Up-Tite makes an aluminum guard that shields this spot from human contact. I've also heard the guys at P-3, Pirie Performance Products(www.pirieperfprod.com), make a guard out of composite material.
11 You can remove two bolts/springs out of the clutch (on opposing sides), so you go from six to four bolts. This reduces the effort at the lever about 30 percent, and after 12 hours of racing we've seen minimal wear on the plates and no perceived slipping.
12 We noticed the rear brake hose can rub on the right-side engine cover as the swingarm moves through its range of motion. We split a piece of radiator hose about 4 inches long, safety-wired it around the brake hose in the friction area then coated the aluminum in this area with Dev-Con Flexane 80 putty. It's black, it covers any wear marks, it looks good and all abrasion ceased. Grainger (www.grainger.com) was our source for the Dev-con.
13 After multiple rides and pressure wash cycles the linkage pivot closest to the bottom shock bolt will be the first to collect dirt and to seize, whereas all other linkage pivots stay free moving longer as they are less susceptible to contamination. One way to help this pivot stay clean and greased longer is to slide a 4-inch piece of neoprene fork seal saver over the lower shock clevis and the linkage pivot. The neoprene will get damaged from coming in contact with the ground, so we replace it quite often, but it works.
14 As I mentioned earlier, the shock can be removed without taking off the subframe. The procedure is to rotate the shock reservoir away from the carburetor to remove and the opposite to install. The rear wheel/swingarm needs to be raised and lowered at two times during shock rotation. Once you do it a few times it's easy.
15 We safety-wire the little clips that hold the brake pad pins in place just as a precaution. Sticks or stones may try to extract these clips otherwise.