Arctic Chat : Arctic Cat Forum banner
1 - 20 of 21 Posts

·
Registered
Joined
·
90 Posts
Discussion Starter · #1 ·
So we got some snow this week and I just had to take out the 2002 ZR600 I just bought.
About 15-20 minutes into the ride (it was warmed up) it stopped dead in her tracks. Any idea what would cause this ??? The sled is EFI and it has 5090 miles on it. Just fatigued pistons ???.
 

Attachments

·
Registered
Joined
·
780 Posts
You leaned out. Gas cap vent working properly? Using ethanol enriched fuel without the proper chip? Coolant low? Fuel filter plugged?

Were both pistons in the same condition? If so, probably one of the above reasons. If only one; I'd suspect a leaky rubber carb flange or plugged/incorrectly jetted/adjusted carb.

After you do the required engine repairs, make sure to find the cause of the lean down before attempting to start/run the sled again.

Had a similar experience with a 2000 ZR 440 Sno-Pro over the past weekend. It was caused by a plugged fuel cap...
 

·
Registered
Joined
·
90 Posts
Discussion Starter · #4 ·
It is EFI.
Only the one piston was bad. The gas that was in it was from the previous owner.
Plugged gas cap ??? Do you mean the vent ?
SDOG
 

·
Registered
Joined
·
352 Posts
Look at the port where the piston ring is sticking out. You can see it very clearly that the lower edge of the port is very sharp. Looks to me like someone forgot to put a chamfer on that port and it cought the ring. Re-sleeved cylinder? Just a guess from what I see.

SPDFREEK
 

·
Registered
Joined
·
90 Posts
Discussion Starter · #6 ·
The previous owner said the motor had never been apart. It has 5000 miles on it. Can you lean out an EFI machine ?
Here is another view of it.
I am going to pull the motor today and see if the crank is ok....
SDOG
 

Attachments

·
Registered
Joined
·
13 Posts
I have a 98 Zr600 efi, That I had lots of learning experience's with. I blew the motor about 4 times & hears what I've learned. First make sure a sled is good and warm before you WFO it, Because the same thing will happen to your pistons. Second I was told not to put oil in your gas for brake in on the ZR 600 efi, at least in the 98 because the screens in the injectors are so fine that the oil will plug the injector and lean out the motor.
Another thing to check is the bottom of your block, on mine I had an old piston in it for a short period that turned into 2 1/2 years, witch made that piston have about 5000 miles on it. When I went out for a ride & the motor quit, so took it apart and found that the piston skirt had broke off and got blown through the bottom of the block & my pic looked like yours. One other thing to check is your boots, and If you don't find anything that would have caused this. When you get you sled running lift up the back, start the motor and spray ether by the PTO. If the sled rev's up your crank seal is gone, also on that note if you were just starting out when it went it could also be the crank seal. Because when you torque on the motor by revving it up, it will pull on the clutch and if seal is weak it will lose seal & suck air in resulting in leaning out that piston. Hope some of this will help. GOOD LUCK thumbguy
 

·
Registered
Joined
·
90 Posts
Discussion Starter · #9 ·
<div class='quotetop'>QUOTE (ny snopro rider @ Apr 15 2007, 01:58 PM) <{POST_SNAPBACK}></div>
Looks like you hit it right on the head....
I pulled the motor and jug. About 1/3 of the piston skirt is missing. I guess I will need to split the case and see what other kind of damage I have.
Is the bottom end on these the same as the ZR800's ? What other kind of performance upgrades are there for the 2002 ZR600's ? I have it torn down, just playing with ideas.
SDOG
 

·
Registered
Joined
·
111 Posts
I've heard the 500 is the same not sure about the 800.i just cleaned out the base and put it back together with a cyl.i bought off ebay.changed intake boots small cracks wasn't why it blew up but why take chances over a few bucks.no problems since.alot of good help on the link above about bleeding the system.
 

·
Registered
Joined
·
780 Posts
<div class='quotetop'>QUOTE (ny snopro rider @ Apr 16 2007, 11:17 AM) <{POST_SNAPBACK}></div>
I've heard the 500 is the same not sure about the 800....[/b]
800 has a balancing shaft in the crankcase, different sized bearing journals, lots of differences.
 

·
Premium Member
Joined
·
4,640 Posts
Ouch! damn, thats a mess. Better it happened now then at the beginning of next season though. At least you wil know where you are at with it starting off next year.
 

·
Registered
Joined
·
13 Posts
If it was the piston skirt that came off, I would just check the bottom of the block inside and out & if the crank case is in good condition. I would Just hone the jug if its not in too bad shape, buy two new pistons, rings, c-clips, hone the other jug, check the o-rings, throw it back together. Then see how it works, it sounds like It was just fatigue, this happened to me on my ZR 600 efi & ZR 580 efi. Put new pistons in, checked the jugs, replaced if needed, honed them out, they are both running to this day. I wouldn't split the cases if you don't need to. When my skirt went through the block I just welded it up then bought this stuff called quick aluminum and put over the weld and the sled ran like a top. Oh one little trick, when you put it back together put a little ATF on your finger, lube up the rings, bearings & put back together. When you first drive it take it cool & should work good. Make sure you check boots, crank seal, reeds, oil lines. Have fun
 

·
Registered
Joined
·
249 Posts
The piston has been rocking for a while. You can tell fron the wear on the port bridge and above the port.
That cyl. is definitly toast. It needs re-nic or replaced. Make sure you replace the piston in the other side also.
Look real close for similar wear in that cyl. also. It may be damaged.
 

·
Registered
Joined
·
90 Posts
Discussion Starter · #15 ·
Yep the one cylinder is toast. I am going to split the case to clean it out and check crank bearings. I rebuilt my ZRT earlier this year with a set of coated SPI pistons. I will probably be using those again for this sled.
Like Jeff said, I want to know what I have for the start of next year.
If anyone has a cylinder for sale shoot me a PM.
Thanks
SDOG
 

·
Premium Member
Joined
·
4,640 Posts
Cylinder can be repaired. Talk to Millenium about it. Any deep gouges etc can be welded and rebored then plated again. It's worth a estimate at least. They also have their core exchange program you can look into. At least that way you get something for your scrap too.
 

·
Registered
Joined
·
90 Posts
Discussion Starter · #17 ·
I ended up buying a 800 mile motor off Ebay for it. I installed it this weekend but it will only sputter and not start. If I put gas in the cylinders it will run until the gas is gone. Didnt I see on here once that you have to unplug something to "prime" it ? I had drained the tank before so there was no gas in the system.
Thanks
SDOG
 

·
Registered
Joined
·
4,097 Posts
<div class='quotetop'>QUOTE (SDOG ZRT 600 @ May 29 2007, 09:09 AM) <{POST_SNAPBACK}></div>
I ended up buying a 800 mile motor off Ebay for it. I installed it this weekend but it will only sputter and not start. If I put gas in the cylinders it will run until the gas is gone. Didnt I see on here once that you have to unplug something to "prime" it ? I had drained the tank before so there was no gas in the system.
Thanks
SDOG[/b]
Use a 12V battery to run the fuel pump to prime the system. I don't know which wires you need to tap into to power the fuel pump, but that is about the only way to run the pump long enough to fill the whole system.
 

·
Registered
Joined
·
222 Posts
Check your fuel lines under your airbox and make sure they aren't kinked. I had a similar problem last winter when I rejetted for a set of pipes on mine. Hope this helps.

Trent
 

·
Registered
Joined
·
780 Posts
<div class='quotetop'>QUOTE (SDOG ZRT 600 @ Apr 17 2007, 11:09 AM) <{POST_SNAPBACK}></div>
.... I rebuilt my ZRT earlier this year with a set of coated SPI pistons. I will probably be using those again for this sled.
...[/b]
I've purchased a set of those SPI coated pistons for our "less than reliable" 2000 ZR440 S/P. Are they any good? I was going to buy Cat pistons, but found the SPI models for a lot less money, and the coating IMHO seems like a good idea. Any good/bad/other on these SPI piston/ring sets?
 
1 - 20 of 21 Posts
Top