Arctic Chat : Arctic Cat Forum banner
1 - 15 of 15 Posts

·
Registered
1994 Arctic Cat Wildcat 700 EFI
Joined
·
25 Posts
Discussion Starter · #1 ·
Just looking for some suggestions & thoughts on a situation I’m possibly in? Sorry for the long story below

I have 94 Wildcat EFI, over the weekend while I was hitting some trails, sled all of a sudden started to bog bad so I cut the motor, found that my coolant was almost completely gone & that there was a very visible leak coming from the base gasket on PTO side. Thankfully I just nearly saved the motor from blowing... Anyways - Yesterday, tore the engine down cleaned off the old gasket, replaced and went to put the buckets on, all seemed good. Reassembled everything, she started up on first pull, BUT sounded a bit off, not sure it better or worse. Then when thinking about it, I remembered that when putting the MAG cylinder on, I didn’t check where the rings were oriented, but they spun freely & she slid into the cylinder without much issue at all (with compressing the ring with my fingers) THEN on the PTO side, i had taken the rings off to clean the channels, and without thinking (it was a long day) put them back in without checking which side was up & which ring was 1 or 2... this piston too slid in without much problem, when i turned the crank w the head covers off - everything looked good..

Question -Do I need to retear down the motor to check the rings or did I possibly get lucky with installation & everything should be fine? Is there any way to check without tearing down?

Also, i read on another forum that if the rings
were upside down, it wouldn’t have even gone into the cylinder - this true?
Any suggestions would be appreciated
 

·
Registered
Joined
·
94 Posts
In my opinion i would tear it down to make sure. A few hours might save more than a few hundred bucks in the future. rings would still go in cylinder either upside down or right side up. Of course new rings usually have a number or symbol near the end gap which usually means up. I find if you take each ring by itself and place a straight edge across the diameter the outer edge should be slightly higher than the inner edge. This is the up direction
 

·
Registered
1994 Arctic Cat Wildcat 700 EFI
Joined
·
25 Posts
Discussion Starter · #3 ·
In my opinion i would tear it down to make sure. A few hours might save more than a few hundred bucks in the future. rings would still go in cylinder either upside down or right side up. Of course new rings usually have a number or symbol near the end gap which usually means up. I find if you take each ring by itself and place a straight edge across the diameter the outer edge should be slightly higher than the inner edge. This is the up direction
So i ended up tearing it down again, everything seems okay.. mag side rings were wedged, and the cylinder was really tight. Caused very minor scoring.. only issue i see is the the pin/notch for the top ring is not there, so the ring spins freely. Do I need to replace the piston head now? Or is there a way to fix that?
 

·
Registered
Joined
·
94 Posts
I would highly suggest replacing the piston especially with a lost pin. Clean up the cylinder with scotch brite, minor scoring should not be a problem. I would suggest an SPI piston or similar because they are a good price and a decent piston.
 

·
Registered
1994 Arctic Cat Wildcat 700 EFI
Joined
·
25 Posts
Discussion Starter · #5 ·
I would highly suggest replacing the piston especially with a lost pin. Clean up the cylinder with scotch brite, minor scoring should not be a problem. I would suggest an SPI piston or similar because they are a good price and a decent piston.
That’s what I figured.. eh new parts never hurt lol. Now my buddy mentioned id have to rehone the cylinder before installing the new piston? Is that case? The cylinder has good visible crosshatching but maybe I’m maybe I’m missing the point.
I will definitely look for SPI then, trying to get a replacement this week so she’s ready for the weekend😬 anything else id need to do when putting a new piston in?

Thanks for the help! Really appreciate it
 

·
Registered
Joined
·
94 Posts
I would highly suggest replacing the piston especially with a lost pin. Clean up the cylinder with scotch brite, minor scoring should not be a problem. I would suggest an SPI piston or similarbecause they are a good price and a decent piston.
That’s what I figured.. eh new parts never hurt lol. Now my buddy mentioned id have to rehone the cylinder before installing the new piston? Is that case? The cylinder has good visible crosshatching but maybe I’m maybe I’m missing the point.
I will definitely look for SPI then, trying to get a replacement this week so she’s ready for the weekend😬 anything else id need to do when putting a new piston in?

Thanks for the help! Really appreciate it
That’s what I figured.. eh new parts never hurt lol. Now my buddy mentioned id have to rehone the cylinder before installing the new piston? Is that case? The cylinder has good visible crosshatching but maybe I’m maybe I’m missing the point.
I will definitely look for SPI then, trying to get a replacement this week so she’s ready for the weekend😬 anything else id need to do when putting a new piston in?

Thanks for the help! Really appreciate it
 

·
Registered
Joined
·
94 Posts
Using a 320 grit ball hone on a Nickasil cylinder is possible, but many don’t recommend it for a few reasons. If the cylinder is in decent shape I just clean up with solvent and rub good with scotch brite. There is some good videos on U tube but also a lot of garbage. If you want to check out a guy who I feel knows his stuff on U tube. Check out Slavensracing. He is KTM 2 stroke bikes, but he knows his stuff on 2 stroke engines and has been around a long time.
 

·
Registered
Joined
·
94 Posts
Clean cylinders good with brake clean or something similar, coat lightly with oil and ensure gaskets and o rings are in good shape. Probably a good idea to raise front of machine up on initial start up to bleed coolant
 

·
Registered
1994 Arctic Cat Wildcat 700 EFI
Joined
·
25 Posts
Discussion Starter · #9 ·
Clean cylinders good with brake clean or something similar, coat lightly with oil and ensure gaskets and o rings are in good shape. Probably a good idea to raise front of machine up on initial start up to bleed coolant
Okay that works for me, I’ll just give it a good cleaning, check everything out & hopefully it’s good to go. I ended up finding an SPI piston at Royal distributing for a decent price, and got a new gasket set as well, although i just replaced most of the gaskets. Definitely paying for my mistake lol. Hopefully after all of this, i end up fixing the coolant leak! & I’ll definitely look up that guy on youtube, sounds like it’d be extremely useful!
Thanks again for your help! I’ll update once I get everything in & back together. Lets hope it goes well
 

·
Registered
Joined
·
4,133 Posts
If the piston rings spin on the piston you'll have a real mess, so good thing you didn't ride it. These engines typically use keystone rings, which refers to the cross section profile, and the sloped surface is the top. They may also have a marking on the top face, too. The locating pins in the ring grooves, on the intake side, keep the rings from rotating and top and bottom rings should be the same. It is always best for new rings to seat on a fresh cylinder surface. the factory procedure, from my shop manual, is a ball hone to resurface the nikasil. It only takes a few seconds to refresh a cylinder with a ball hone, but I have heard of guys doing it by hand with a Scotchbrite pad. The more you can do to promote a good ring seal the better it will be.
 

·
Registered
1994 Arctic Cat Wildcat 700 EFI
Joined
·
25 Posts
Discussion Starter · #13 ·
If the piston rings spin on the piston you'll have a real mess, so good thing you didn't ride it. These engines typically use keystone rings, which refers to the cross section profile, and the sloped surface is the top. They may also have a marking on the top face, too. The locating pins in the ring grooves, on the intake side, keep the rings from rotating and top and bottom rings should be the same. It is always best for new rings to seat on a fresh cylinder surface. the factory procedure, from my shop manual, is a ball hone to resurface the nikasil. It only takes a few seconds to refresh a cylinder with a ball hone, but I have heard of guys doing it by hand with a Scotchbrite pad. The more you can do to promote a good ring seal the better it will be.
Yah, I’m super thankful I only started it for a couple seconds before I realized my error.. came out of it with pretty much no damage, a very minor scuff on the cylinder but nothing to remotely be worried about. Ended up cleaning up the cylinder with a scotchbrite pad, new piston, put the rings in right lol, fresh gaskets, and everything seems to running top notch.

BUT now I’m even more frustrated with it - While i was working on it, i found a leak at the weep hole, so got a new seat of seals, took that apart; impeller looked really good, shaft had some surface rust, no pitting so cleaned that up & it looked mint. Cleaned up everything, seals in and put back together. Took it for a test rip today, only to find it still leaking from the weephole, I’m at a loss. Went through all the necessary steps, even talked to the techs at the cat dealer to get tips on what to look out for when doing it - all good. What could have possibly gone wrong?

i read online that sometimes if you don’t replace the seals on the bolt that secures the impeller (ofcourse the only ones I didn’t replace) that it could cause a leak? Would that really be the case?
Y’all have any ideas or tips? I’m so close to just callin it & taking a loss on the season😕
 

·
Administrator
Joined
·
2,726 Posts
Not replacing the sealing washer on the impeller will cause a leak, as can an impeller that is loose on the shaft.
You don't want to touch the ceramic sealing surface of the mechanical seal or get any oil/grease on it.
More than one person has installed the sealing disk in the impeller wrong as well, the rubber side goes in, and the hard ceramic side goes out to ride on the spring loaded ceramic portion in the case
 
1 - 15 of 15 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top