Most common Raptor 660 problems explained (Read this before posting your problems)
This is just a start. My goal is to have one post in which the most common problems that 660 owners face will be described and resolved - to perhaps eliminate some of the constant repeats we get every day.
I’ll be adding to this as I have time, and as readers contribute pertinent information. I'm going to spread this across a couple of posts, because the system only allows 10,000 characters per post, and I'm already way past that.
Below are, IMO, the most common problems that 660 owners have, based upon the number of times they show up on this and other forums. I’ve tried to give a concise description of the problem and a detailed explanation of the fix. If any one has anything to add, please add a post. If it is an obvious improvement over mine, I’ll be glad to edit it into this, the 1st set of posts.
Also, if anyone has pictures related to any of these subjects, please post them below and, if applicable, I’ll edit them into these 1st few posts also.
If I’ve overlooked anything, you are welcome to add your own opinions on common problems and solutions here.
Please note that there is new information added to #3 - "My Bike Won't Start" regarding the 'unplug rectifier/regulator to get spark back' problem... see "NEW EDIT AS OF 3/27/2011" in Post #2
Here's whats in here so far, an Index, if you will -
1)MY STARTER MOTOR TURNS, BUT IT DOESN’T TURN THE ENGINE OVER
2) MY ENGINE IDLES GREAT BUT IT SPITS AND SPUTTERS WHEN I JUST BARELY PRESS ON THE THROTTLE
3) MY BIKE WON’T START – THE STARTER CRANKS THE ENGINE OVER, I SMELL GAS, BUT IT JUST WON’T START
and here's what I plan on adding in the near future:
4) NOTHING HAPPENS (OR I JUST HEAR A CLICK OR BUZZ) WHEN I PRESS THE START BUTTON
5) I HEAR A CLUNKING NOISE FROM MY TRANSMISSION IN ONE OR MORE GEARS
Suggestions for more?
Ok, here we go -
MOST COMMON PROBLEMS AND THEIR SOLUTIONS:
1)MY STARTER MOTOR TURNS, BUT IT DOESN’T TURN THE ENGINE OVER
Starter one-way bearing – the 660 has a systemic problem with this component, Yamaha had a bad design. Symptoms are grinding noise while starting and/or the starter turns but sometimes the engine doesn’t – it may take several tries, or it may not work at all.
Once the one-way begins to fail, it starts dumping small pieces of metal into the oil sump. You don’t want these pieces ending up where they shouldn’t (like in your tranny gears) so it’s a good idea to replace the one-way at first evidence of a problem.
We all recommend that you do not buy an OEM Yamaha one-way, it will just repeat the failure at a later date. Consensus here is that the L&A or Extreme aftermarket one-ways are a much more robust design and are likely to last much longer – for most, the life of your quad.
Also necessary, most of the time, is replacement of the 52 tooth gear which has a smooth bearing face that the one-way engages. As the one-way fails, it usually chews up this bearing face on the gear. If you don’t replace the gear too, this scarred face will end up damaging the clutch sprags on the new one-way bearing… NOT what you want. If the bearing face on your 52T gear is not as smooth as silk, replace it.
A website called raptortranny.com had a fantastic treatise with pictures – walking you through the replacement process step by step. Unfortunately, they no longer exist. I have posted an archive of those pages in a sticky called “How to replace the starter one-way bearing (From Raptortranny)” in the 660 General Discussion area of this forum, the link is - How to replace the starter one-way bearing (From Raptortranny)
2) MY ENGINE IDLES GREAT BUT IT SPITS AND SPUTTERS WHEN I JUST BARELY PRESS ON THE THROTTLE
RPM limiters - Most 660s have three RPM limiters – Max RPM (which will not be dealt with here), Reverse RPM and Parking Brake (PB) RPM limiters. If either the reverse or the PB electrical circuits fail, these limiters will be invoked by the CDI and the engine will cough, spit, backfire, even die sometimes when the throttle is just barely applied.
Reverse limiter – The engine has a reverse switch, a small, circular 1 pin switch in the engine case just under the output sprocket. The switch button, which extends into the case, is depressed by the reverse gear moving into its operating position. This switch is normally closed (shorted to ground) EXCEPT when the bike is in reverse. A wire, GREEN with WHITE STRIPE leads from this switch up to the CDI.
The CDI (computer) looks at the reverse switch wire and if it is at ground, it assumes all is normal. If, however, the CDI sees that the reverse switch wire is NOT at ground, it assumes the bike is in reverse and it turns on the RPM limiter and the Reverse indicator light. Note: Early ‘01s do not have this limiter, late 01’s do. If you have it, you would know it from the limiting of RPM’s when in reverse.
Failure of the switch, unplugging the reverse switch wire, dirt or corrosion at the wire’s connection to the switch or if the wire is broken somewhere between the switch and the CDI will all fool the CDI into thinking the bike’s in reverse and turning on the RPM limiter AND the light.
IF your light blinks or flickers randomly (NOT at a fixed on/off rate), or is on all the time (assuming the bulb works), then this is likely your problem. Find the GREEN with WHITE STRIPE wire’s connection to the switch, unplug and clean all the connecting contacts, tighten the spring clamp in the connector and re-connect.
An option here is to just ground the GREEN with WHITE STRIPE wire to a clean spot on the frame or the battery negative terminal. This eliminates the possibility (assuming the wire is intact all the way back to the CDI) of this problem occurring again, BUT it also disables the reverse light. I have a sticky in the ‘660 Modifications’ section on how to lose the reverse limiter but keep the light. Look at it if you wish. It's here: Lose your reverse limiter but keep the reverse light - instructions
BTW, another possible cause of this same issue (reverse limiter) is if the GREEN with WHITE STRIPE wire has broken somewhere along its path to the CDI. Look carefully at the wires, especially around the CDI and in the battery box to detect any possible damage. The reverse light should be on in this case (assuming the bulb and wiring to the bulb is ok).
Parking Brake limiter – The 660 has a switch up on the clutch perch dedicated to sensing when the parking brake has been engaged. (I believe that some or all ‘05s do not have this). When the parking brake is on, the switch is engaged (closed) and shorts two wires together – GREEN with YELLOW STRIPE and BLACK. These wires come from the harness to a connector and then to the switch. The black wire is ground. The CDI looks at the GREEN with YELLOW STRIPE wire and if it senses it at ground, it turns on the RPM limiter. If you are feeling the symptoms described, spitting, sputtering, etc., but it can not be explained by the reverse switch issues mentioned above, it may be the PB switch.
Simply unplug the PB switch connector to eliminate this as a possible cause of your problem. The connecter is white, has two pins, has BLACK and BLACK wires coming in one side and GREEN with YELLOW STRIPE and BLACK wires coming in the other side. The connector is hidden up behind the left headlight near the radiator. A sticky with some pictures regarding the PB switch and it's removal is here in the forum: How To: Remove PB Sensor
Water and dirt, if allowed entry to this now unplugged connector, can short across the pins and cause the limiter to come on again. To prevent this, seal the connector (the one with the GREEN with YELLOW STRIPE wire that leads to the harness) with silicone caulk or equivalent to keep out all foreign debris.
BTW, another possible cause of this same issue is if the GREEN with YELLOW STRIPE wire has chafed and is shorting to ground somewhere along its path to the CDI. Look carefully at the wires, especially around the CDI and in the battery box to detect any possible damage.
CONTINUED IN PART 2 BELOW
__________________ '01 660 Raptor, Burgard +2+1 arms, YFZ Shocks, LSR anti-vibe, CTR pipe, jetted, K&N
'01 Polaris Scrambler 400, K&N
'02 Honda 400ex, Big Gun pipe, jetted, K&N, Lonestar +2 A-arms, Lonestar anti-vibe
'02 Honda 400ex, DiamondJ +3 A-arm widener, Lonestar anti-vibe
3 scooters - 150, 180, 250
'73 Yamaha CT3-175 Enduro (currently under restoration)
'08 Can-Am Spyder SE5 - my Baby!
And the newest toy destined to suck up all my spare time and money: 2000 Jaguar XJ8
Last edited by QuadManiac; 03-27-2011 at 02:14 PM.
Reason: asked to
3) MY BIKE WON’T START – THE STARTER CRANKS THE ENGINE OVER, I SMELL GAS, BUT IT JUST WON’T START. or - it runs, but badly, especially at certain throttle positions.
1st (if it won't start at all) check for spark – pull the spark plug and plug it back into the spark plug boot. If you have a spare spark plug, leave the plug in the engine and use your spare for this. Ground the metal body of the plug to a clean spot on the engine. Crank the starter and look for good, strong (preferably blue/white), CONSISTENT spark across the plug gap.
If there is NO spark: Stator – a common 660 problem is an internal short in the stator windings – between the windings used to charge the battery and the another winding that leads to the CDI.
To test for this failure, unplug the rectifier/regulator and try again. Unplugging the rec/reg frees this common short that is pulling CDI signal and it now allows the ignition voltage to be generated – spark returns. If this works, your stator needs to be replaced (SEE NEW EDIT, 2nd PARAGRAPH BELOW FOR A POSSIBLE SOLUTION WITHOUT REPLACING THE STATOR). A good article on stator replacement is in the forum here: How to replace stator.
If you do have success by unplugging the rec/reg, you can leave it unplugged indefinitely with no concerns about damage to the bike…. But your battery will not be charged. Ride all you want, don’t use your lights and limit the number of shutdowns/restarts as this will discharge the battery quickly. You can charge the battery regularly with a charger, and keep jumper cables with you just in case.
4/23/2012 - Here'a a great video showing the loss of spark problem, and the cut red wire solution, put together by our friend Banshee2Raptor - Stator , red wire revival.
NEW EDIT AS OF 3/27/2011:
Thanks to feedback from several members and verification work done today by CenCalRacing (thanks to all of you)there is a possible solution to this problem WITHOUT having to replace the stator:
If unplugging the rec/reg DOES return spark to your engine, plug it back in and try cutting the red wire that comes from the stator (FROM THE STATOR, out of the side cover - NOT FROM THE REGULATOR). This red wire is from the stator's rotation direction winding and has proven to be not necessary; I believe it is legacy from kick start versions of this engine where it would prevent the engine from accidentally starting/running in backwards rotation.
If the short is in this winding, cutting the red wire appears to eliminate the short and return spark, without any other issues - allowing you to plug the rec/reg back in and return to full bike operation: You get spark and the battery charges correctly - all is good! This has now been verified several times by forum members with the 'unplug rec/reg to get spark' problem. BONUS: It has been reported and now verified that this also increases the reverse (and perhaps parking brake) RPM limiter's RPM limit by about double, so for those times when you just couldn't get enough reverse power, this may fix that issue.
If cutting this wire DOES return you to operation, you are good to go... if it does not, try cutting the white/blue stripe wire, also coming from the stator - this is the other side of the same stator winding. If you now have spark, great... if not, then it's stator replacement time (or leave the rec/reg unplugged as described above).
ALSO, I ask you a favor: If you do this mod, please add a post at the end of this sticky's thread telling us about your results - success, failure, RPM limit changes in reverse and/or parking brake, etc.
END EDIT 3/27/2011
If there IS spark: Carburetors - The biggest cause of no start, poor start, poor running (as long as you haven't made any recent mods) is dirty carburetors. The 660, because it has 2 carbs, uses smaller than normal jets, for an engine of this size. Because the jet’s passages are so small, they are very prone to being plugged up by solids left behind when gasoline evaporates from the float bowls. The pilot jets (responsible for idle) are especially prone to plugging. Sometimes, leaving the bike unridden with the petcock on for just a few weeks will cause plugging of a pilot jet. To prevent this, close the petcock and let the engine idle till it dies, whenever you're going to let the bike sit for more than a few days. This nearly empties the float bowls and will eliminate any evaporated solids from gumming up the jets.
Note: If you are trying to tweak your mixture after having made mods, look at the link referenced below, and others in this forum.
If no start: Spray some starting fluid into the carb intakes and quickly try to start it. If it catches fire and tries to run, you are probably not getting fuel into the engine due to carb issues (assuming fuel is reaching the carbs).
If you have popping on decal, poor response when you first press down on the throttle, which recovers quickly, a slow return to idle when you've released the throttle, or just plain sloppy idle, it may well be clogged or partially clogged pilot jets. You can try turning out (CCW) the pilot screws (front, bottom of the carbs, screwhead up inside small cylindrical bore) about 1/4 turn at a time. First, turn them clockwise while counting turns until you bottom out... return CCW to this count - their original positon. Start experimenting from there, 1/4 turn or so at a time, keeping count. If you have to turn any further than 3 1/2 - 4 or so turns from bottomed out and you still haven't got the performance you want, then either your pilot jets are plugged or they need to go larger.
The only solution to these problems (if pilot screw adjustment didn't work) is to dismantle and thoroughly clean the carbs, the jets, needles, choke plunger, float valves and all passages. I prefer to use spray carb cleaner, toothbrush, and thin copper wire (a strand or several stolen from a piece of speaker wire). Make sure that all passages in the carb body have been sprayed until you can see the spray exiting from another passage (they all end up somewhere else), and then blow clean with compressed air.
Each jet should be inspected, sprayed with cleaner, especially through their small diameter passages, rodded out with the copper wire, then sprayed again and blown clear with air. When done, you should be able to see an nice, circular shaft of light coming through the jet’s passage. If it’s not symmetric, clean some more.
Great post Quadmaniac, always of great help. The one thing I had problems with my 05 660 was with warped rear rotors, I tried adjusting my PB a million times and still had to change rotor 3 times in 6 months. Donīt know it this is an issue of the 660 or just me!
2006 Raptor 700
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