You did it again didn’t you? Even though you know better, you left your bike to sit alone and unloved over the winter, without so much as a kind word or soft touch, let alone any proper maintenance. Now it’s payback time.
For once, I’m going to forget the lecture about an ounce of prevention being worth a pound of cure. We all know the consequences of riding them hard and putting them away wet. Let’s move on and get the bike back on the road with as little pain as possible.
Occasionally you can beat the odds. I’ve seen plenty of bikes that sat in the cold all winter fire right up come spring, and run just fine to boot, once the cobwebs were blown out. If you’re feeling lucky, go for it; who knows, maybe the bike will shake it off—if you’re lucky. Most of us, especially those that live in colder climates, aren’t going to be that lucky, so chances are good you’ll have some work to do before that first ride.
Modern bikes place high electrical demands on their batteries, so if yours isn’t in decent shape it’s unlikely you’ll be going anywhere until it is. Ideally, the battery should be removed from the bike; cleaned, and inspected—including a load test if possible—and fully charged before being put back into service. You and I both know that isn’t always going to happen, in some cases because the manufacturers seem to go out of their way to make removing the battery as complicated as possible, and in others, because you just don’t feel like doing all that work when you can more easily connect a charger to the battery where it sits. I get it, but at least wipe down the top of the battery to remove any conductive grime, and make sure the terminals are clean and tight.
If you’re still using a lead/acid wet cell battery, check the fluid level, and top it off before recharging the thing, preferably using distilled water; again we both know you’re going to top it off with tap water, and frankly in my experience that’ll work just as well. Chances are the battery will die an unnatural death from other causes long before the minerals in the water kill it.
What’s that gunk in the float bowl?
It's best to check-and preferably...
It's best to check-and preferably change-all your bike's fluids if it's been sitting idle all winter.
As gasoline ages, some of the more volatile components evaporate out, making what remains less effective as a fuel. Stale gas creates starting and performance problems, at least until it burns off or is drained and replaced by fresh stuff, so of itself, it’s not a huge problem. Unfortunately, as the process occurs, hydrocarbons in the gas react with oxygen to change the chemical composition of the fuel. This leads to gum and varnish deposits in the fuel system. Gum and varnish don’t work particularly well as an energy source, but they do an outstanding job of plugging up the small ports and passages that carburetors and injector nozzles use to meter fuel, so they’ll need removing before the bike runs properly.
The smaller the volume of fuel the quicker it’ll turn to goo so the first priority is to drain the float bowls. This is done by loosening the float bowl drain screw and letting the old crap run out of the float bowl drain, preferably into a catch can or at very least onto old towel or rag. Don’t forget that, while it may no longer be much good as a fuel, it’s still a volatile, easily combustible liquid, so treat it, and any contaminated articles with caution.
If the drained liquid is really brown and sludgy, your carbs may be past the point of no return (see the side bar for your options), but be advised that if things have gone too far, a total carburetor strip and rebuild may be the only way out. Assuming it still resembles gas, let the bowl drain completely, then remove the drain screw, taking care not to lose any O-rings or washers, then spray a blast of carb clean (making sure to protect any painted areas) or WD 40 into the float bowl to help clean out any residual sludge.
Stale gas can gum up your...
Stale gas can gum up your carbs, and you may have to drain and clean out the float bowls to get to the sludge.
If your bike has a petcock with an external removable screen (a rarity these days) now’s the time to inspect and clean that as well, and to replace any fuel filters. If the gas is foul, you’ll need to drain the tank, and refill it with fresh fuel, and again take the necessary precautions.
By the way, some manufacturers place a small screen at the fuel line inlet to the carburetor, and debris there can cause hard-to-diagnose fuel delivery problems. I’ve yet to see one completely plugged, but I’ve found several that were plenty dirty, so it pays to pull the fuel line and check them from time to time.
EFI systems present different concerns. Although it’s not an everyday problem, contaminated fuel can plug injector nozzle tips or prevent the injector from operating properly. When that happens, your only recourse is to remove the injector for service, or replace it. Fortunately, some of the pour-in cleaners that are now available work very well, and in many cases can restore a balky injector to some semblance of health. In every other respect what holds true for carbureted bikes applies to EFI-equipped ones; i.e., if the fuel has deteriorated into something that looks like tar, you might as well drain the fuel tank and replace the filter now, as you’ll be doing it eventually anyway.
While you’re poking around in the fuel bay, take a few minutes to examine the air box. I’ve seen mice build nests in a motorcycle’s air box overnight, and given a few months they can construct a veritable condo. If it’s been inhabited by anything other than the filter, give it a thorough cleaning. Allow me to digress here and point out that rodent infestation should never be taken lightly. I’ve seen more than one engine ruined because mice made their way into the engine through an open valve and camped out in the cylinder. Besides the mess they make with their nesting material, mouse urine is highly corrosive, and they’re not very particular about where they spray it, so you can imagine what the inside of your mill will look like if Mickey decides to set up housekeeping in it.