Need expert opinion!

[crashingsucks]

I know this is a yamaha site! (As you guys know I do have an RX1) My question is for my spare sled, 96' polaris xcr600 sp (triple,triple)! I just recently rebuilt motor (wiesco pistons and rings) got it all together and running! The problem is the clutch side cylinder is firing very eratic and sometimes not at all, the other two are fine! Its getting fuel but not flooding (even swithed carbs around) The coils are good, I swaped those as well! Same problem same cylinder!! Could this be the CDI box?? I am at my wits end and need any and all help!!
Thanks in advance, Crash!

 

[vcrash]

Im sure you already did a compression check but thats where id start, then check the crank seal,vaccum test,you have already checked everything else so check the cdi, good luck,oh ya check the reeds,one might be curled or cracked

 

[crashingsucks]

Vcrash, I did do a compression test and all are exactly the same! I didn't split the case so the crank seal is still good! The funny thing is that the two other cylinders are running great! If I had a vacume leak would that affect the other two cylinders? I did put a vacume gauge on the line that goes from the case to the fuel pump and the vacum pulses are within factory paremeters (3-5 psi) Did I check this the correct way if not please elaborate!! If it matters the sled did sit for a couple of years! And one more quick question, is the cdi box what actually tells which cylinder to fire or is that already taken care of before the box???

 

[Srxspec]

did you check all your wiring connections? if you did then i'd take a look at the stator, there should be readings to tell you if that is good or not but you'll need a volt/amp meter. maybe check and switch the plugs around and see if that's doing it?

 

[crashingsucks]

Srxspec,I tried switching plugs, coils and even the carbs! Is the stator what controls the spark to the individual cylinders I'm kind of illiterate when it comes to the stator and cdi box! I'm exactly shure how they work! The first thing I actually did was use a volt meter to see if there was a problem with the coil!!

 

[Srxspec]

The stator could be weak. I'm not sure how it works on that particular model, if the coils are connected in a series so they all recieve power from the same two wires, but it could be that there's enough power to fire 2 of the cylinders but when it comes to the third (the farthest one away) it doesn't have the juice to fire it? Hopefully that makes sense!

 

[crashingsucks]

Srxspec, actually that does make a lot of sense but the problem is there wired in paralel, each coil has its own source wire from the cdi box!!

 

[Srxspec]

well there's the only answer I have for ya. I'd try another CDI box and if that doesn't do it then look to the stator!

 

[crashingsucks]

Thanks for your help srxspec, one thing is for shure changing the cdi box would be a hell of alot easier than changing the stator, I just hope thats the cause- will know shortly!!

 

[4phsyco]

Before you screw around with the CDI, I'd check plug wires also. I believe this model Polaris has all plugs fire at the same time. Just switch around your wires and see if a different cylinder now gives you trouble.

 

[POWERHAULIC]

Check the resistance of the spark plug caps, they should be 2000 ohms.

 

[Pinball Wizzard]

Unless Im missin somthing here, dont put the cart before the horse. Are you loosing spark or not. Sounds like yor not sure or why are you changing carbs and coils and -----. Check for spark, pull a wire while its running bad or go get a spark tester that goes in line and make sure. If you have spark all the time than add some spray A LITTLEcarb cleaner throu the boot and see if it wakes up or not . Check compresion and do a leak down test. Find someone with a lab scope and check for pattern failers. Guessing sucks!