01 raptor 660 running issues

[Redsand069]

my friend has an 01 yamaha raptor 660 and it has running issues. when he bought it, it had been sitting for a while, but right away he cleaned out the carbs, put new gas in the tank, changed plugs, and it ran fine. about a year ago it started acting up. it would start, somtimes be hard to start. when it started, it would seem to idle fine most if not all the time, as soon as you give it gas, it would pop and backfire, and just fall on its face. after that, if you take the plug out its black. he cleaned the carbs out and tried it again, same thing, so looked it over, cleaned the carbs again, same thing. he pulled the spark arrester off to make sure that it wasnt plugged and, put a new spark arrester back on it. he took it to a performance repair shop and they also took the carbs off, cleaned and boiled them, put them back on, same thing. then they told him to get a cdi box, or module, whatever yamaha calls it, he found a used one that was off a previously perfect running quad of the same year, it did the same thing, they told him to try and get a speed sensor, i found a used one for him, it tested fine, and put it on, still acts up. any ideas or suggestions on what to try??

[beeze455]

first, unplug the white connector behind the head light that has a green/yellow stripe wire and black wire. This disables the PB sensor and you can always plug it back in, but I would leave it unplugged.

second, take off the green/white stripe wire down by the sprocket and ground it out to the engine. I added a circular wire connector and removed a starter screw and slipped it through.
This disables the reverse rev that most do not have anyways, but be warned that the reverse light will no longer work.

[Redsand069]

well, he tried this, and it wouldnt even start. any ideas or suggestions on what to do next? hes worried it could be the cdi box.

[atlraptor9]

Well the cdi could indeed be junk. Did u test the stator? A short in any of the stator wires could lead to faulty starting. Those I feel would be the two main possibilities. The stator or the cdi. And the first thing that should have been checked is the ignition coil. If ur not getting sufficient power from that, that's probably the reason it has intermittent starting issues.

[yfzrider690]

I can almost bet that the valves need to be adjusted. Has he done this since he has had it? If not that would be the first thing I would check. If the vavles are out of spec it will be hard to start and not run very good.

[atlraptor9]

ya i mean all of these are possibilities. i wish u lived in mass, the shop that sponsors me is great they do diagnostics to narrow down the problem but u still have a wide range of possibilities

[Critch]

Originally posted by beeze455
first, unplug the white connector behind the head light that has a green/yellow stripe wire and black wire. This disables the PB sensor and you can always plug it back in, but I would leave it unplugged.

second, take off the green/white stripe wire down by the sprocket and ground it out to the engine. I added a circular wire connector and removed a starter screw and slipped it through.
This disables the reverse rev that most do not have anyways, but be warned that the reverse light will no longer work.


This worked great for me but a thanks bezze seems everyone around these parts were puzzled excellent job. thanks

[Redsand069]

well, he tried this, and it didnt work, so idk what hes got planned to try next, he keeps wanting to try a new cdi box

[miles Machine]

try this...when its running and starts to pop and back fire turn the lights on...if it clears up then its a faulty regulator rectifier that is overcharging the cdi...a 100% proper way to check it is to put a multi meter on the battery and rev it to 3000 rpm and it shouldnt charge over about 13.5-14 volts....if this is what is happening you coulda fried the cdi

[Redsand069]

hey thanks a bunch, i will def try this, any help is def appreciated!!

[towman]

whats up guys my cuz has a 05 660 and when he puts it in rev. it stalls out any ideas?

[mikecancu812]

does it just stall out or does it start sputtering when you give it throttle. theres a rev limiter on it that cuts the motor out if your tryin to back up anything bigger than a mole hill. you hit certain (low) rpms and it starts sputterin

[orange mustang]

check the intake boot from the carb they will stall and backfire when the boot leaks its a common issue happens to my bike after a long wheelie and wreck