Each month we receive an overwhelming flood of technical questions from our readers. Everyone at ATVR including the night janitor carries an extremely heavy workload, so as a last resort we were forced to put Mike Newsom in charge of answering your questions. Mikey is one of the most talented mechanics we know, but it's his off-the-wall remarks and repulsive attitude that keep him locked away in the garage. If you dare to bear his response, send your questions to firstname.lastname@example.org
. We promise not to let Mikey use your name and embarrass you in front of your buddies.
Ask: I have a 1988 Honda FourTrax TRX300FW, and when I put it in fifth gear and give it gas, it revs quite a bit harder than usual. Do you think the clutch may need an adjustment or something?
Mikey: It seems odd to me that an individual with enough common sense to realize that his clutch is likely slipping would have to write to Mikey before making an adjustment. This just seems as if you're craving the verbal abuse that you know I'm going unleash. Now, finish reading your magazine and then go attempt adjusting your clutch with the clutch adjustment screw located on the right engine case. Your machine is over two decades old, so don't be alarmed if it's in need of a new clutch. These do need replacing on occasion.
Ask: I bought a 400EX that was running at the time of purchase. I even drove it up ramps into the bed of my truck. When I got it home, it began to get sluggish and would stall. It felt like the choke was on (it wasn't). I limped it back to my shop, and it only started once after that. I cleaned the carburetor and checked the spark. I'm getting good spark, and the bowl is full of fuel. Now it won't start, and when I pump the throttle, I hear a mechanical click from the cylinder. It sounds almost like a valve is hitting the piston, but only when the throttle is pushed. I'm not seeing an obvious solution and wonder if you can point me in a good direction.
Mikey: The first thing you must realize is that your valves don't react whatsoever to the pumping of your throttle. But when the throttle is open the slide lifts and normal engine noise becomes more evident. Are you sure it's not just your trusty Timex that you hear ticking? Since you just bought this used machine you could go ahead and check your valve adjustment. This is a simple task on a 400EX. I know you claimed to have cleaned the carburetor, but I'm not aware of your mechanical skills. Make sure you thoroughly clean out all the jets and fuel ports. The smallest piece of overlooked debris could be the root of your problem, and just because there is fuel in the bowl doesn't mean it's making its way into your cylinder.
Ask: I'm from South Texas. I have a 2004 Yamaha Bruin 350 2x4. It had been sitting for about a year when I bought it dirt cheap for a project. I changed all fluids, replaced the battery, installed a new plug and checked for bad fuses. I still can't get it to turn over. I then cleaned the carburetor. I know I'm getting fuel and I have a spark, but it just seems like it doesn't quite have the extra compression it needs to turn over. So before doing the top end sooner than I had planned, I wanted to adjust the valves. In doing so I noticed the exhaust valve had more lash than I care to say. So I'm leaving it alone and asking advice on how to get it unstuck for more compression. I punched a service manual online, and the PDF will not download for some reason. If you can point me in the direction of a good, easy-to-download service manual, I'd appreciate it. And any advice on the valve would be greatly appreciated!
Mikey: Howdy Tex, I don't know how you cowboys do it down in Texas, but we Georgians don't buy project quads unless we're certain we possess the necessary skills to make the repairs. There's no easy button to repair a dropped valve, and extra compression doesn't make an engine easier to turn over. Is your engine locked up completely? Did it grenade on the previous owner before he stumbled upon a sucker in a ten-gallon hat looking for an easy project? Maybe this is why you bought it "dirt cheap." Ha-ha, I'm just busting your chops, Tex. Put a compression gauge on that Bruin and see if you can turn it over manually. You should already know how to turn it over if you checked the valve adjustment.
Ask: I'm looking for the fuel filter on a 2006 Bombardier 400 HO. I cannot seem to find one anywhere. Is there one, and if so, where would I find it?
Mikey: I'm curious to know just how hard you've searched... I know my way around an ATV, but I can't recall every detail about each machine that our reader's questions are referencing. I occasionally pull up one of many online microfiches to get a detailed view of a particular unit. In your case, I had your answer in less than two minutes. You probably wasted more time than this trying to spell Bombardier. If you'll do the same, you'll find there are two inline filters on the front right side of the fuel tank. The same sites that supply the microfiche also sell the filters for around $10. Another thing to remember is that Bombardier is now called Can-Am. This should eliminate any complications during your search.
ASK: The speedo on my 2005 Yamaha Kodiak 400 has stopped functioning. The cable on the back of the speedo is still firmly attached. I'd like to upgrade to a digital model, but my research has not found a Kodiak digital dash. The only product that looks like it may work is Trail Tech's Endurance digital display. Although Trail Tech doesn't carry a specific model for my machine, it seems a magnetic device attached to the end of the cable coming from the speedo gets its reading based on a magnet that rotates around the device on the end of the cable. Is this generally how it works? Do you think I could mount the end of the speedometer cable in a certain place on my ATV so long as the magnet constantly rotates around it? My initial thoughts were to mount the end of the speedometer cable in the open hollow end of my rear A-arm and then put the magnet on the rim as it's constantly rotating and moves simultaneously with the end of the A-arm. You can check it out at www.trailtech.com.
Mikey: After spending a half hour correcting your spelling and grammar, I now feel obligated to answer your question. Personally, I couldn't care less about having a speedometer, but if I were in your predicament, I'd simply repair the stocker and hit the trail. Simple digital gauges do work as you have described. They detect the rotation of a magnet like those on bicycles. Yes, an inexpensive bicycle computer would do exactly what you need. I suggest calling Trail Tech; it is excellent with electronics and probably has a simple solution.