MadMan

Its been a while since my last post. To recap, I have a snorkel and after market DG RCM slip on exhaust installed on my 98 yamaha 350 4x2 big bear. The raised the carb NEEDLE up a bump and changed my Main stock jet from #120 to a #145. Bike was running great afterwords. It was peppy and sounded killer. I recently had it in storage for maybe 4 months and now its running crappy. It doesnt want to idle for very long, keeps stalling. It drives fine with light or medium throttle but if I punch the throttle the revs stop. Its like a let off the gas when in reality Im holding it down. If I drive up steep incline the motor stops. It will then start back up once bike is on flat ground again. Could this be due to a sticky float in carb? This bike had a float that would stick about a yr ago and I chgd the needle valve set. Maybe it needs to be done again or a simple cleaning? I forgot to check the carb drain to see if it was pissing fuel last ride. Thats usually my clue the float is stuck. The needle valve set looks like its made out of aluminum and the tip appears to be dipped in rubber. Last time I changed it the alum looked pitted which caused it to get stuck in place and not move freely with the float. I hope its a simple fix. For an old bike this thing is solid! Yamaha built it like a tank and it drives like one too. LOL!

I think I`ll have to pull out carb to examine it. I once had trouble with the float sticking and the carb used to get flooded and pour fuel out of overflow line. Maybe float is sticking again? Its just weird the bike runs pretty solid from low throttle to 3/4 throttle, but when I punch WOT it stalls out and when I drive bike on a steep hill it stalls out. Does this sound like the carb is being flooded with gas? I`m no carb expert but I have taken the thing apart several times since I`ve bought bike, so I`m familiar with the components. I think my next ATV will be EFI for sure. LOL!

Hey Oxi-Black, I own a 1998 Big Bear 350 4x2 with a similar spark plug issue. I recently pulled out plug and she is BLACK. It is a NGK D8EA. Heres some background info; I installed a snorkel on her a couple years ago and raised the carb needle one notch and it ran alright until the stock muffler rusted out completely. I upgraded to a DG RCM ll slip on exhaust and bike ran only so so. It backfired when I would punch throttle and sputtered a little when I would be creeping thru a watery mudhole. I rejetted the carb. The bike ran great and was very peppy. Exhaust no longer backfired. After a long ride the hot motor would sometimes stall out when I would creep thru a watery hole on trails. Bike has sat in my shed for MONTHS and I recently went to drive it and it runs like crap. Its hard to start, doesnt want to stay idling, and if I drive it up an incline it stalls. It also stalls if I punch the throttle. I went to drive it up my trailer ramps and it kept stalling. I changed the spark plug for new one. I test drove it and same result. I immediately removed plug after 10 min of riding and its already getting black. ANy ideas? DO I need to rejet carb again? I thought I had it dialed in perfect but now it runs like crap. The stalling when I go uphill is really weird. If u need to know the size jets I replaced the stock ones with, Ill have to find the paper I wrote it down on. I did this months ago and cant remember the Jet sizes. I plan on cleaning the carb since it was sitting for several months with no use. I live in FL so this bike never sees severe cold weather. ANy help is appreciate bro.

OK good advice. Well I bought the yama 350 as my first quad and Popo 500 bought as a replacement, but some how it became my wifes choice ride. LOL. Ill do some test sitting at some dealers before I decide. I am even considering a 2up quad, altho choices are slim. Only Polaris, Can Am, and AC make 2 ups currently. I would buy a yamaha 2up if they made one. I dont know much about AC, Can Am seems pricy, so that only leaves Polaris. LOL. We enjoy riding in a group and not all our friends and family own quads, so we end up riding double a lot.

oxidized black - LOL, yes. U know exactly how I feel. A circus clown, haha. If I drive solo Im on 500 popo but if we ride together I ride the 350 Big Bear. Tough bike, but its simply too small for my long legs. Im going to visit one of the BIG atv stores near me that carry multiple brands and see how each feels size wise. I really like Yamaha build quality. Never let me down or my friends down. Ive owned a few polaris bikes and they ride nice but Ive had issues with each. The popo cvt seems have to rev high to make bike move initially, plus I hate not having a sep front and rear brake hand lever. I really like Front Locking dif opposed to AWD on Popo and Canam, but I do like how FAST the Can Ams are. Lots of riders in my area ride Can Ams Outlanders. Im not into racing utility quads but I do like a bike that can pop a wheelie or punch thru mud. My polaris 500 almost lifts the tires from dead start punch of throttle, but the CVT seems to be geared for Easy, smoother acceleration, not torquey like a Grizzly. I read the Can Am 500 Outy lacks low end torque. I like riding trails, but I want something to handle some mudholes too. Whatever I buy its getting upgraded tires with decent lugs. I have SUper Swampers on rr of my Big Bear and they churn mud like crazy. That 2wd bike drives thru a lot of crap, except extreme mud.....where 4wd is needed.

Hello everybody, I need some advice on buying my next utility ATV 4x4. Ive narrowed it down to Arctic Cat, Yamaha, Polaris, or Can Am. Im wanting something with a 500-850 motor. I def do not want a 1000. They just seem too big and heavy. I am 6ft-5in tall and medium build. I currently drive a 1998 Yamaha Big Bear 4x2 350 and its simply too small for my body size. I also own a 2000 Polaris Sportsman 500 4x4 which fits me quite nice and has a comfortable large seat. My wife loves driving the Popo since its automatic, so I get stuck driving the Yamaha if she tags along for ride since its semi auto shift. Id like to trade up the Big Bear for a larger, reliable, capable, trail and mud machine. I must have 4 wheel drive and IRS. I like the reliability of Yamaha, but I must admit my Popo rides quite smooth. I just really dislike the Polaris CVT belt noise and the lag time it requires to move atv after u punch the throttle. I havent tested the new 2013 or 2013 popo sportsman to compare. Im not into extreme mudding, but my friends and I do snorkel our quads and drive thru deep water on occasion. So I would like an ATV that is water friendly, if there is such a thing. LOL! Ive pondered a can am xmr 650 but am worried the can am might be expensive to maintain or repair. I really like the look of the AC Mud Pro, but I have no problem modifying a base model to suit my needs. Whatever bike I buy MUST be large in frame size. I dont need gobs of power but I prefer a larger frame size. My Big bear and my buddys Honda Rancher are just too small. My butt actually hits the rear rack when I ride if I sit bk too far. Please share your thoughts, good or bad. I am not brand loyal, I just want a well made, larger frame bike for trails and some mud. Thanks!

Another update, well I finally finished putting my new heavy duty cvt belt on and EPI clutch kit. Now when I shift into gear the bike doesnt grind. WooHoo! I only road the ATV around my yard and up and down street to see how the cvt was engaging. This EPI kit works well. It came with 2 primary springs and one secondary spring and a new helix. The bike takes off like a rocket now! I bought the kit with the intention of changing my current stock 25" tires for taller mud tires. This EPI claims its designed for tires 27"-28" tall. Ill update again after I trail ride it. BTW if u want to tackle a CVT kit like the one I installed u will need this special Polaris CLutch spider removal tool. I had to make a jig to hold the clutch in place and I unscrewed the spider off. Its torqued down tight so youll need a breaker bar to crack her loose.

Well Motoverse.com back when their Vin Decoder link worked was great. Its been down for months. Luckily when I bought my yamaha I used it and got the info I needed before site stopped working. My polaris I used PUREPOLARIS.com and logged in my VIN. I got both bikes Registered and tagged now so Good News, neither were stolen bikes. WooHoo! This is always my fear when buying things thru Craigslist. A hand shake deal with no title can sometimes lead to problems. If u cant find a free online VIN decoder, just contact the manufacturer and they can provide u with all the info about your bike thru your VIN number. You may have to email custoemr service and wait several days but its an option. Some decoders aren't truly decoders. They merely just tell u who its registered to or tell u if bike is stolen, they don't always provide you with the specs of your bike. Sites like Cheapcycleparts .com are great for looking up OEM parts and they show exploded diagrams of how all your parts go together. Even if u don't buy from them, the diagrams are helpful. U simply enter your Bike brand, model, year, and engine size. Good luck!

Hello ATVers, I need help aligning the belt on my Polaris Sportsman CVT. I bought this bike used and noticed a little smoke coming out of CVT exhaust under heavy throttle (smelt like burnt rubber). The previous owner claimed he installed a new belt, but when I opened up cvt cover I noticed belt was out of alignment causing the edge of one side of belt to fray. A small chunk of the belt was missing in one area. I removed one of the washers from behind the secondary pulley to move belt back to alignment with primary pulley. The washer acts like a shim and removing it moved the secondary pulley back about 1/8" which is what it needed. I don't like moving the pulley so close to the back of the plastic cvt case but my alternative (per the service manual) is to loosen the motor mounts and move the motor slightly to change position of the primary pulley and then re-tighten the mounts. Please correct me if this info is wrong. I haven't done this step, but I will do so if someone with more CVT experience could chime in. My son and I went for a ride and he typically drives in HIGH range which I'm told is bad for slow trail riding or driving thru mud. Primarily what we drive on are slow forest trails and very muddy sections. Apparently the combination of him being in HIGH range and the belt already frayed caused it to break. So I ordered an EPI sever duty cvt belt and a clutch kit since this bike's cvt has never been serviced. I plan on installing bigger tires for mud, so I ordered a kit designed for this type of riding. Any advice on how to adjust belt tension and alignment would greatly be appreciated. I don't wanna blow another belt. Standard OEM belt is $70 and this severe duty belt is $100!! They are not cheap.

Soco499; Yes, I did fix mine. I adjusted the carb needle to remedy my problem with throttle. I opened up the carb, pulled the needle out, and moved the needle clip one notch down which raised my needle slightly. By raising the needle position it makes bike run a little RICH. My snorkel mod increased my airflow, so I needed more fuel to compensate. The bike previously was running like crap. It'd bog down when i would punch throttle from a stand still. Now throttle response feels right. My stock exhaust is rusted to Hell, so I am ordering a new DG RCM ll slip one exhaust from Amazon. I'm sure I'll have to rejet my carb afterwords. I'll keep u posted how the bike runs after the install. BTW I have discovered no one sells an after market slip on exhaust or these old Big Bear bikes. A stock Yamaha ugly steel can one cost more than a new DG pipe. I hope it's not a POS. Good luck with your Big Bear! These old Yamahas are bullet proof IMO.

OK here's an update. I adjusted the throttle screw on my bike's carb and lowered my idle. The bike no longer grinds when I put it in gear, but still requires a bit of force to pop it in gear. I removed the cvt cover and discovered the pullyes were out of alignment. Previous owner had recently chgd the CVT belt and never adjusted the alignment or didn't notice. Any way the belt is slightly chewed on one side in one small spot. I fear it's going to wear prematurely due to this. It started to fray on same side it was rubbing. I was able to align the belt on pulleys. I did notice the belt is spinning while it's in neutral. Is belt supposed to spin in neutral? I thought it was supposed to not move or only move slowly. The bike still pops into gear but it's not grinding. I think this feeling of the shifter popping into gear might be because the belt is moving. My old Polaris Trail boss belt used to spin in neutral but when I pressed the rear foot brake pedal it'd stop. My newer 2000 Polaris sportsman 500 rear foot brake pedal doesn't seem to affect the belt spinning in neutral. I think this bike is due for a clutch kit. Replace the old cvt spring and weights that are probably worn out. BTW the bike has severe engine braking. When I let off the throttle the bike slows down very fast as if it's braking. Is this a sign of the CVT needing repair and/or maintenance? I like this bike and I'm trying to save money and repair it myself. My local ATV shop has high hourly rates for work. Any help is greatly appreciated!

Hey thanks. I will adjust the idle down tonight when I can. Previously it was set so low the bike kept stalling, so I bumped up the throttle a tad. I'll lower it bk down and see if I can find the perfect setting between NOT stalling and NOT grinding when I shift gear. On a side note, I did notice one quirk about this bike and how she shifts gears. If I am towing something heavy with the bike and it's under tension I cannot shift gears. If I am in HIGH gear it will stay in HIGH gear. I discovered this when i was rescuing my buddy stuck in the mud. I went to tow him out of a hole and after moving a few feet forward, I stopped, and went to shift into reverse to back up and release the tension on tow rope. The hand gear shifter moved but the bike was not changing gears. It was stuck in HIGH forward gear. I manually pushed the bike back enough to release tension on tow rope and Voila! The bike could shift again. Now my Big Bear sometimes does the same thing, (shift from High forward to REVERSE) especially if bike in on an incline, but if I rock the quad back and forth the gear shifter shifts fine. My '98 Yamaha Big Bear 350 is a semi auto, I must shift with foot lever. I'm still discovering the good and bad about this Polaris. The bike rides really smooth. It just takes a lot of revs to make the CVT move the bike. That's another reason I want a clutch kit. I'd like her to engage the wheels sooner when throttle is squeezed. It's a work in progress.

I recently bought a 2000 Polaris Sportsman 500 4x4 with CVT. The bike runs great. Starts right up and motor sounds solid. My problem is sometimes when I shift into gear it grinds as I'm shifting. I always make sure the bike is at a complete stop, I press the foot brake on, and I shift the lever into HIGH or LOW or REVERSE and it grinds as it pops in gear. I'm guessing maybe the idle is too high or I may need a new clutch kit. It has the original stock CVT clutch (springs and weights) so it's probably due for some maintenance. I have adjusted the throttle screw on the carb and when I first turn on bike when cold it idles fine, but after I've been riding a while and she is good and warmed up she idles slightly higher which then creates this horrible grind noise when I shift into gear. My old '92 Polaris Trail Boss did the exact same thing but I found if I applied the foot brake it stopped it from grinding. Pressing the foot brake as I shift doesn't seem to help. I have not opened up the cvt cover to investigate the pulleys yet. Any advice before I start dismantling parts? I'm thinking I will adjust my idle down a little. If this doesn't help I'll take a look at the CVT. Previous owner claims he installed a NEW belt, but never messed the pulleys. And on a side note I plan on changing the stock 25" tires with some 26" or 27" mud tires. This would be a good reason to upgrade my bike with a clutch kit. It would help turn the bigger tires and I'm guessing it might help with this grinding problem. Any help is greatly appreciated. I am handy with a wrench, but I am not a mechanic by trade.

Hey thanks bro! That link works gr8! It not only told me make and model but even the color was "green", lol. That's cool. I appreciate the help. I own a '98 Yamaha Big Bear and a '00 Polaris Sportsman and it's helpful knowing the exact model numbers. I learned there were about 8 different models built during my model yr and when you are ordering replacement parts it's good info to have. Thanks again Oxi-Black! :cheers2c:

Hello gang, In the past I have always used the website Motoverse.com to decode VIN numbers for my ATVs. Recently I attempted using the websites VIN decoder link and for months it's been out of order. Does anyone know of another website that decodes VIN numbers for free? My friend just bought a used Yamaha Big Bear and he wants to run the VIN. Verify if it's stolen and confirm the exact model quad. I managed to verify my Polaris VIN on the PurePolaris.com website. Any one know of another VIN decoder besides Motoverse.com to look up Yamaha ATV? Thanks guys.

I own a 1998 Yamaha Big Bear 350 4x2. I recently purchased a Submarine Snorkel brand snorkel kit for it which didn't fit properly, so I decided to build one homemade. I ran 1.5" PVC from the stock air box up to the front of the quad. It passes thru the front right fender and pipes into a 2" PVC mounted to a crash plate on the front rack. I connected the crank case breather line into the 1.5" PVC as well. I made a 2nd Snorkel on left side of quad which is a faux snorkel since it's purpose is to conceal the breather lines I have extended from the rr drum brake, rr dif., and carb. I took care to loop the breather lines a couple of times to prevent water from getting in, in the event I ever sink the quad. I also siliconed the air-box lid and used Dielectric grease on all electrical connections. I don't go swimming with my Big Bear but I do ride thru fairly deep water occasionally and I just wanted the snorkel installed as a precautionary measure for those unexpected dips u take when traveling across what u thought was a shallow puddle on the trail. LOL. Any way, since installing this snorkel my quad has an odd throttle response. When riding at normal speeds it's unnoticeable, but when hammering the throttle or fluttering the throttle the response seems to lag. I also notice if I'm in a gear too high for the slower speed I'm going the quad sounds like it's about to stall. I know normally u downshift the slower u drive, but it used to drive in a higher gear at low speeds and not bog down like it does now. I'm told I should re-Jet my carb. I'm pondering installing Dial a Jet. Any suggestions from you experienced riders? Removing the carb is a PITA and reinstalling it is equally fun. I've already rebuilt the carb prior to snork install. I like the concept of a dial a jet being able to adjust on the fly, but wasn't sure if it's the way to go. Please help. Any advice is greatly appreciated guys!

OK I'll ask Swampact07. OMG for a SXS yes, the Wildcat is my top choice. Amazing machine, but BIG. I even like the Polaris RZR 800 because it's only 50" wide so it's approved for OHV trails. I don't ride in EXTREME mud but I do go thru mud trails and water. I even pondered the Artic Cat Mud Pro which is already snorkeled and looks killer. The Can AM XMR looks bad A$$ too but it cost as much as a car! I'm trying to gear up for family atv trips. I currently own a 98 yama Big bear 350 and a 92 Polaris Trail Boss 250. With 2 boys and my wife we need bigger or multiple machines. I think those sxs 4 door models r waaaay too long for trails I typically ride. I was wanting to get a 2 up atv for starters and eventually get a 2 man sxs so all four of us can ride around safely.

Hey Thanx bro. Lemme know if u come across one. BTW being you are a Yamaha fan I have a question for you. I currently ride a '98 yamaha 350 Big Bear 4x2, but I'm shopping for a new(er), larger, 4 wheel drive quad. I'm pondering a 2 up quad because many times I ride with my wife or my son as passenger. I realize this is unsafe, but I ride at slower speeds when riding double and use extra care. The only 2 up ATVs on the market are Polaris Sportsman, Can-Am Max, and Artic Cat Cruiser. I love Yamaha, BUT they do not offer any 2up ATVs yet. Out of the 3 I listed, which would u recommend? I'm leaning towards Polaris because in all the reviews the ride quality is rated high and their prices seem fair. Can-Am is rated ok, but they seem expensive. I don't know much about Artic Cat reliability. I drive mostly in dirt/sand, but this quad will get into some mud and water. I don't do much rock crawling here in FL. I love how Yamaha has true 4 wheel drive with locking front end. The can am and Pole are on demand 4wd or 3 wheel drive as some ppl call it. What are your thoughts?

LOL! Very True. I came to the same thought after researching the work entailed in converting the old beast. It's a great solid atv and has never left me stranded. Luckily the engine braking on this thing works great so I can usually stop even when the crappy drum brakes are barely working. I just like to use a parking brake when I load my big bear on my flatbed trailer and this rr brake sucks. I'm in the market for a larger newer quad so I think this old machine will remain with it's awful drum brake system. Thanks for the advice Oxi-Blk.

I own a 1998 Yamaha Big Bear 350 4x2. It has hydraulic drum front brakes and mechanical single drum brake in rear. When I bought the quad a yr ago the brakes barely worked. I installed rebuild kit for brake master cylinder, replaced wheel cylinders up front, front/rear shoes, and replaced rear brake cable. The front brakes grab sort of ok now, but the rear barely grabs at all. On a side note; If I drive through any trails with muddy water, moisture is getting inside the drums. Worse in the rear drum. These drum brakes have never worked great. They slow me down but don't have enough bite to lock up the wheels. Now I have considered my drums may have worn thin, therefore causing the shoes to not make strong enough contact (???) I'm guessing. The front brakes are spooned out so they fit snug and they work just ok. The rears I have adjusted close to the maximum setting for the actuator arm. I read online about a Yamaha 1998 Big Bear 4x4 owner using a 2004 Big Bear 4x4 front disc brakes on it. He did have to dremel and drill out the lower ball joint to make new knuckles fit since the 04 knuckle has it's ball joint on bottom. It sounded cool and the owner claimed it stopped better. I'm considering a conversion, but it sounds expensive. I hate sinking $400+ worth of disc brake parts into a quad a bought for $500, and I already replaced the existing brake parts I previously listed. I'm just tired of my brakes working poorly and every time I get into some water on the trails the drums look like a septic tank inside the next day. I live in FL and this is the land of the Swamp. There is no avoiding mudholes and water. I would like some brakes that could survive any wet conditions. Any suggestions or helpful advice is appreciated.

Hey you wouldn't happen to have a service manual for a 1998 Yamaha Big Bear 4x2 (YFM350 UK) would you? I picked up a Clymer manual but the pictures in the book as really dark.

UPDATE; Well my starter died, so I installed a brand new one ($60) in the Polaris Trail Boss. To remove the starter it requires removing the CVT cover and pulleys (special puller tool $30) to access a few bolts on back of starter. I got the new one in place and re-installed the CVT. Quad is still hard to start with COLD motor, BUT I popped cover off airbox and sprayed starter fluid in it while starting engine and it immediately started running. After she warmed up I turned her off and tried starting her again. She starts immediately like she should. Thanx AjmBoy for the advice. BTW some how after removing the CVT and re-installing it while installing the starter my quad is now faster. It's faster off the line and I gained 10mpg on my top speed. Maybe my CVT was in dire need of lube or I don't know what, but some how this quad is quicker. When I bought it it's max speed was 35mph and now she goes 45mph. I was pondering buying a Clutch kit because I'm sure the CVT springs and internal parts are original. I'm thinking this would help performance on this 1992 atv.

This is on OLD thread, but maybe my answer could help others who have similar problem. Yes, it should slide off. I bought a heel toe shifter for my 1998 Yamaha Big Bear. I removed the bolt of the existing toe shifter and my toe shifter slid off with a little pulling. Try spraying it with PB Blaster and/or use a flat head screw driver to pry between the open side of where it clamps on. It you can pry the clamp mouth open a tad, it may make it loose enough to pull off the splined shaft. Just be careful not to damage the splines on the shaft.

Right, bluetooth is cool, but I didn't want to drop serious coin on the ability to talk on trails. We take our 2 ways camping and when we go ATV riding in woods. They work great when the cell phones won't work. BTW this is off topic, but if u ride offroad and CAN get a cell signal try using Google "My Tracks" app (it's free) on your GPS smart phone. I've used it a couple places we ride where cell towers are within range and it's cool seeing the satellite view of the trails u ride. U can even upload the tracks and email them to friends or send still shots like the one I've attached. I have an old Garmin eTrex that works ok, but the screen is only black and white and it's runs very slow. One time I had a rider get lost from our pack and I sent him "My Tracks" link from my phone to show him where we were on trail. We were lucky our cell phones had signal. This only works is u aren't deep in the forest tho. I wish I had a Satellite phone with GPS and wireless talk, but I'm not rich so for now I use cheap 2 ways and cell ph when i can. LOL!