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I have a 425 Magnum that idles great but seems to flood out when I rev it up, sputters, backfires a little somtimes. No water in gas, good fuel filter, carb seems to be fine, good working diaphram. Plug change makes no difference whatsoever.
Thought i would share a fix that I came across. I was working on a 99 scambler 500, The customer complaint was that even with the fuel shut off the tank would slowly drain out onto the ground. First I found the fuel shut off was bad/ leaking/ dripping so I installed a new one thinking that would fix it. Then I ran it and and seen that the overflow was flowing fuel out from the bowl. So I cleaned the needle and seat and changed the float height to lower the fuel level in the bowl. Well... It still overflowed and flooded. So I bench tested the needle and seat with a pop off tester. I found that these newer style needle and seats just utilize an o-ring to install the brass seat into the carb.
The o-ring for the seat had hardened up allowing fuel into the float bowl from under the seat. New o-ring and problems solved.
Hey guys, new here, but haven't found ANY answer to my specific problem on a Suzuki dedicated ATV forum, so here's to hoping!
I acquired a 95' Quadrunner 250, 4x4, (LT4WD) for practically nothing with no spark. The PO had tossed in a used stator which didn't fix the problem... so I went all routes (though cheaply) to narrow down the initial problem of no spark.
Plug, coil, CDI (caltric) and stator w/pickup (caltric) were purchased and installed. And it RAN, but bogged horribly and would not rev past 1/4 throttle.
I checked fuel flow, vacuum lines, all the normal stuff, no issues. I decided to check the valves and cam... well, there was one problem. The cam was 1mm under the lowest spec in the manual. So, in-came a new cam, Stage 1 Hotcams... also threw in a new set of shindy valves, lapped them, replaced the valve seals, and the timing chain.
Back together again (w/stock airbox and new oiled filter). Now it idles even better, still boggs at 1/4 throttle, but will rev past it if you hold the throttle open for a second. Ahaha... success!
So I was able to ride it above 1/4 throttle once I had momentum... could shift through the gears, all was good as long as I kept it over 1/2 throttle. Took a long enough ride to break in the cam properly at least so I won't have to worry about that.
Now, I start fiddling with the carb. It's clean as a whistle, stock, with stock jets (new replacement Mikuni jets). Same problem.
I start thinking, maybe this is fuel related and the bike is having an issue transitioning from idle jet to main jet... so I LOWER the needle by raising the clip 1 spot. Now it revvs up in neutral with no bog, but it boggs about the same trying to ride it. So I move the needle down again with the clip on the top slot. Better, but still has a bit of bog at 1/4 throttle.
The last bit of advice I got was to ditch the CV carb... so I sprung for a brand new Mikuni VM30-83 round-slide. Bolted it up, blew into the vacuum tube to fill it with fuel (no vacuum port on this one) and she fired right up... but there is still a bit of bog, it's just masked by the fact that I'm not waiting for the vacuum diaphragm to open.
So I feel like each little step brings me closer, but not perfect. I'm now wondering if this is still in-fact a carb tuning issue (I have some jets I can fiddle with and maybe lean-out the idle jet a little.) OR if the cheap-a** Caltric Stator/Pickup is what's causing these issues.
I have a 95' KingQuad with 400 miles on it... like new.. runs like a top... I've tried both the stock QR and the Caltric CDI boxes on it, and it revvs up and runs like a champ.
The only unknowns between the two systems are the carb, and the stator/pickup. My next step in troubleshooting is to rip apart the King Quad and test it's CDI on the Quadrunner... but considering there is no change to how it runs I doubt it will lead to a solution.
HOWEVER... I tried the stock CDI just recently after running the Caltric this whole time, and the bike runs like garbage. Hardly idles, and won't rev up at all. So, that is my one smoking gun telling me that it's either the pickup coil or the stator itself.
Has anyone had a problem even CLOSE to this? I can't image the carb would be causing this many issues, especially going to 2 different ones, both with stock jetting to OEM, and exhibiting the identical symptoms... the only change is when different CDI's are plugged in, or when the needle valve leans out the mixture.
Also, I checked the piston, rings and bore when I had it apart and they're like-new... no scoring, rings are loose, cylinder is still round and has honing marks still int he bore. Stock piston, stock bore size and it has 160psi compression. Battery is brand new, and I've tried 3 different R/R's, none of which change any symptoms, but slightly vary the charging voltage by .2-.5 of a volt depending on which unit. Also tried a new coil which changed nothing.
ANY help would be appreciated. Too much invested to not get it running right.
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Female riders are drastically increasing in numbers every day. Look for them at any trailhead, and you are bound to notice a growing percentage of the riders these days are indeed women. Getting out on the trail and riding full speed ahead is just as exciting for women as it is for the more traditional male rider; however, before you hit the trail wide open, there are a couple of things that you need to take into consideration.
First off: Always be prepared! Remember: You must prepare for the accident then enjoy the ride! Don’t be misled. There is a common misconception that ATVs are a lot safer, say for instance, than a dirt bike, just because they have four wheels and can stand up on their own. This assumption sometimes leads to disaster. Sure an ATV can stand on its own. So as long as you are sitting there, looking pretty posing for a picture, you should be just fine! However, going around a curve, up a hill or slamming into something head on, you might want to be aware of a few other facts. For instance, an ATV is typically 2 to 3 times heavier than a dirt bike; and when it lands on top of you, you will know why that is important! Also, this will be important when it gets stuck in the mud or off over an embankment. Always be prepared to lift something 3 or 4 times your own weight out of an unplanned location! The best way to do this is utilize either the buddy system or a winch/tow kit on the ATV itself. This fact also has to be taken into consideration during loading and unloading the ATV. Speaking of the buddy system, that is always a good idea. Never ride alone and always make sure someone knows where you are going to be riding and when you plan to return from your trip. There are other things to remember as well. Always carry a first aid kit, a bottle of water, a whistle and a radio.
The first aid kit will come in handy if you or another rider is in any sort of accident, or even scrape your hand trying to change a spark plug! A bottle of water is useful to wash out any cuts or abrasions or to wash the dust out of your mouth after following too closely behind someone up a dusty trail. The whistle will definitely come in handy if you happen to go off over an embankment and need someone to find you. A whistle is much louder than a scream and is more likely be heard over the sound of the motors of passing ATVs. The radio can come in handy to let others know of your location or to call for help in an emergency. You can also use it if you get lost, or maybe to have your mate bring you an extra soda on their way up to where you are. Don’t skimp on safety gear, either. Always wear, at least, a Snell- or DOT-approved helmet and eye protection. I also recommend gloves, ankle high boots, long sleeves, and pants. You never know when a briar across a trail either will suddenly rip through your skin or get brushed out of the way by the denim of your jeans or better still, your riding pants. The choice is yours.
Always check your equipment thoroughly before you take off. Be sure to check the tire pressure. They should all be inflated to the same pressure. If the pressure is different in tires opposite each other, it will make the ATV very difficult to handle even in the best of situations. The appropriate tire pressure is usually between 2 and 6 psi. Check your owner’s manual for the appropriate psi for your ATV. (There is usually a sticker on the ATV with this information as well.) In addition, check the tires for cuts or gouges that could lead to leakage or a blow out. Make sure the brakes are fully functioning as well as the lights, kill switch, ignition, and throttle. Don’t forget to check the fluids like gas and oil for evidence of any possible leaks. When camping on the trail, make sure to take everything you will need with you. Nothing is worse than waking up to horrible morning breath miles from the nearest store and instead of being excited about the day’s ride, all you can think about it is how you would trade those new hand warmers for one dental travel pack! Always pay attention to personal and equipment safety as well.
ATVs are high on the list of ‘most often stolen items,’ as they are regularly sold again and again throughout their life without license, titles, bill of sale, certificate of ownership, etc., which makes them very hard to trace. In addition, being in the minority as a woman rider, you do stand out on the trail, so take extra precautions with your personal safety. Be aware of your surroundings and again, the buddy system is recommended on all rides. Here are a few other quick tips for everyone: Be familiar with your ATV and look at the owner’s manual if you have any questions. Never ride beyond your ability! Do not ride double unless your ATV is built specifically for double riders. Doing so makes the ATV less maneuverable, harder to handle, and more likely to turn over or flip. Riding on hard surfaces actually makes it harder to turn an ATV. Do not ride on hardtop unless you have tires specifically for that type of surface. Ride legally and always leave the area better than you found it. Keep the noise levels down by making sure your muffler system meets the 96 decibel limit that was established in 2003.
Alcohol and drugs do NOT mix with ATVs. Be courteous to other riders. When on a trail, always show respect to the environment and other riders. Never lend your ATV to unskilled riders. Know and respect the laws about letting children under the age of 16 ride an ATV. Never put your foot down when riding an ATV as a cast will definitely put a damper on going dancing next Saturday night! Lean forward when going up a hill. Go slow going up a hill, but try not to have to stop or change gears, as either one of these actions can cause the ATV to flip backwards. Never back down the hill. Turn the quad around and go back down the hill forward. Be sure to lean back as you are going down the hill. Aways try to keep the center of gravity as low as possible by keeping all the weight you can on your feet.
You can usually accomplish this by standing up. Remember to keep your knees flexible to avoid possible injury or strain. Do not pull back on the handle bars when going up a hill. Never use the front brake when going forward at excessive speeds or down a steep slope. These are only a few of the tips you should heed when heading out on the trail, but they are a good start. There will be other things you discover along the way. One final note: Don’t let this article discourage you from riding. It is meant to install enough fear to make you a bit more cautious and safe enough to ride for years to come. I hope to meet some of you out on the trail, always with the rubber side down! Have an awesome ride!
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