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Discussion Starter · #1 ·
I have a 1996 ZRT 600, that ran well for a small amout of time after i bought it then i died in the back of a field.  Now it starts but won't move.  I've figured out that the cylinder closest to the flywheel is not firing.  It has good spark outside the cylinder but seems 2 be dead inside.  I have tried different plugs, didn't work.  Timing possibly?  Carb looks 2 be working fine, plenty of fuel in it.  Any suggestions?
 

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cant be timing because all three plugs fire at the same time so if it was timing all three would be dead

do a quick compression check by putting your finger over the spark plug holes and pull it over slowly you will discover quick if there is no compression in the pto cylinder

you probably have a busted piston i had a buddy with a 97 ZR 440 that a chunk of the piston busted off between the two rings on the exhaust side causing blow by lucky for him the chunk was immediatly pushed out the exhaust and didnt even touch the cylinder

make sure the PTO side carb as gas in it as well by removing the plug on the bottom of the carb if you can get in there
 

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Discussion Starter · #4 ·
Each cylinder has excellent compression.  Im going 2 try swapping the #3 carb with the #1 carb and see if that makes a difference.
 

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Check your coil. You can have a bad coil that won't fire under compression but will fire outside the cylinder.
 

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Discussion Starter · #6 ·
When i was swapping the carbs i noticed i couldn't get the choke cable out of the one that wasn't firing.  It seems 2 be lodged in the carb.  I thinking it has been stuck on full choke the whole time, making that cylinder run super rich.  I will also check the coil tomorrow.  You wouldn't happen 2 know the resistance values of the coil would u?
 

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Make sure your water traps under the carbs are fine. You would probably see gas dripping out of the bottom of your sled if that hose was broken. But it is worth a check.
 

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SWRules , make sure your carbs. are cleaned and syncronized, very important on these sleds,also check the fuel pump impluse line for crackin, check the needle in the slide make sure it didnt come apart and is just sittin inside of slide doin nothing, i had same problem a few years back on one of my zerts, and it was carbs out of sync. good luck hope this helps.....
 

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Discussion Starter · #10 ·
I've tried about everything and it still doesn't work. I was wondering if anyone thinks it is the throttle position sensors. I'm told they change the timing as the throttle is increased, could one of them be bad? If so how do you tell? Also is there any way to adjust them or do they need to be replaced?
 

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I think they make a bypass kit for the sensors. Also try moving the plug wire to a different cylinder I think the ZRTs fire all three at the same time correct me if I am wrong.
 

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If you lost the PTO side cylinder, did you check to see if you lost the crank seal? What was the color of the plug on the PTO cylinder? If it was grey you probably lost your crank seal which causes it to run lean. I've seen this before on a Polaris triple. We were on the trail and he lost the PTO cylinder. This was right after rebuilding the top end. At first we couldn't figure out why air was blowing out of the carb instead of being sucked in! He was lucky since the crank seal failed so catastrophically that it really didn't get a chance to run lean very long. The PTO plug was grey in color.
 

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In 96 there was a problem with the magnets in the switches. Mine were replaced by the dealer under warranty in 96.
 

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:withstupid:
Mine were replaced under warranty also. I can't remember the symptoms but I know It didn't run right at the time.
 

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1. Is compression good in suspect cylinder?
2. Swap plug wires. Does problem move?
3. Swap carbs. Does problem move?
4. What do plugs from that cylinder look like.
5. Bypass carb safety switch (TEMPORARILY) to see if problems goes away in that cylinder.
6. Whatever happened with the choke issue?
 

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I would check for a broken reed, what about the choke issue, check the pilot jets (you have to remove it to check it, use a good screwdriver to remove it) and be sure there isn't anything in it, it must be perfectly clean the hole is only about .022" in dia. ???
 

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If you haven't fixed your prblem yet, I believe that your
having the same problem that buddy of mine had with the
same machine. That he bought last year, and I talked to another buddy mine. Who explained to me about those
stupid interupters that get plugged into the back of the
carbs, to sence freeze up and they will shut down the
cylinder. If you are like my buddy with the ZRT600 you
didn't get the by-passers for it. Just try to by-pass them
if you have them. I did this last year and after that no
problem, ran great. If I remember correctly unplug all
three from carbs and tie them up so they're not hanging,
then I think I followed them back to a common plug and
jump them to by-pass. If not you need to by-pass all
three.
It worth a try.
Before I by-passed we went for a ride, started missing
and seemed like it was foweling a plug, it got to the point
I had to towe him home.
Good luck.
 

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If that problem goes away there should be no reason you
couldn't leave it.
My buddy drove his like that all year, and still riding like
that.
To my knolodge your machine is the only one that has
those interupters.
 

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Originally posted by Barry123@Dec 18 2002, 11:43 PM
If that problem goes away there should be no reason you
couldn't leave it.
My buddy drove his like that all year, and still riding like
that.
To my knolodge your machine is the only one that has
those interupters.
Almost every carbed Cat from that era, even recent, have the carb safety switches.
 
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