I just tore down my second Two stroke Polaris with lack of compression to find Wiseco pistons with stuck rings. Both pistons looked like new, very little carbon on top , one with none on the bottom. I dont really know the history of the quads, I buy them all cheap. But I was surprised to find what I thought was very little hours on the rebuild and pistons stuck solid, I couldnt get the one unstuck with soaking and a chisel. I have never found this with Namura or stock pistons and was wondering is this a common problem with Wiseco.
Stuck rings on Wiseco Pistons.
- Thread starter Panzerman
- Start date
- Status
Never had a problem with Wiseco on my dirtbikes...even though that was years ago, I wonder if perhaps they were installed incorrectly, or the wrong parts were used?
It would explain why you got them cheap...hack puts them together wrong...they don't run right...he unloads them...
It would explain why you got them cheap...hack puts them together wrong...they don't run right...he unloads them...
Last edited:
Curious....is there a different engine "warm-up" period with the Wiseco pistons compared to stock?
The atvs weren't related at all. They were bought months apart from different people and they weren't really hack jobs. I like to buy them un-molested, so I know what you mean. Beach Rentals are the best, just rusty, but never beat on and seldom wrenched on. Wiseco pistons are forged, therefore they change sizes from. Cold to hot. Stock pistons and Namura are cast. I prefer cast. I've found stock is ussually the longest longativety.
Kinda wierd, never had that problem in the past with wiseco pistons or any others for that matter. Correct rings? Installed up side down?
Email Wiseco and ask'em.
Email Wiseco and ask'em.
Originally Posted By: Panzerman
I just tore down my second Two stroke Polaris with lack of compression to find Wiseco pistons with stuck rings. Both pistons looked like new, very little carbon on top , one with none on the bottom. I dont really know the history of the quads, I buy them all cheap. But I was surprised to find what I thought was very little hours on the rebuild and pistons stuck solid, I couldnt get the one unstuck with soaking and a chisel. I have never found this with Namura or stock pistons and was wondering is this a common problem with Wiseco.
Are you saying the rings are stuck on the pistons, or are the rings stuck in the bore? After I re-read your post I realized you talk about stuck rings and no compression, then later a mention of pistons stuck solid.
I just tore down my second Two stroke Polaris with lack of compression to find Wiseco pistons with stuck rings. Both pistons looked like new, very little carbon on top , one with none on the bottom. I dont really know the history of the quads, I buy them all cheap. But I was surprised to find what I thought was very little hours on the rebuild and pistons stuck solid, I couldnt get the one unstuck with soaking and a chisel. I have never found this with Namura or stock pistons and was wondering is this a common problem with Wiseco.
Are you saying the rings are stuck on the pistons, or are the rings stuck in the bore? After I re-read your post I realized you talk about stuck rings and no compression, then later a mention of pistons stuck solid.
I have no idea what oil they were using, the carbon wasnt terriable on the pistons though. The rings are stuck solid on the pistons. I couldnt get the ones out of the one, with a chisel, the piston was like new, so if I could have gotton the rings out the piston was re-usable. The other piston, I actually broke the ring, but still couldnt pull it out of the groove. I ve never seen piston rings stuck like that. It was just wierd to see two pistons, same problem, that close, both Wiseco. I ve never seen this with stock or other after market pistons. Ive probably tore down 10 quads now.
Almost sounds like they were cemented in. Maybe the rings used were too large for the ring lands and once they were jammed in, they can't be remove?
strongly suspicious of wrong ring sets.
Q.
Q.
i've seen this before.
improperly sized and therefore siezed rings. entirely the fault of wiseco.
typically wiseco pistons are forged not cast and the warmup on them is a little different (ie longer).
however, i've seen properly warmed up wiseco's still sieze the rings.
you dont say if this is a 2smoke or a 4banger. i've seen this on the bugkillers.
on my 4strks i tend to run either oem or JE piston & ring setups.
improperly sized and therefore siezed rings. entirely the fault of wiseco.
typically wiseco pistons are forged not cast and the warmup on them is a little different (ie longer).
however, i've seen properly warmed up wiseco's still sieze the rings.
you dont say if this is a 2smoke or a 4banger. i've seen this on the bugkillers.
on my 4strks i tend to run either oem or JE piston & ring setups.
I've seen this on rings installed up side down, usually wind up in the trash.
I'm not a big fan of Wiseco pistons, had many stick in the bore and ring problems.
Smoky
I'm not a big fan of Wiseco pistons, had many stick in the bore and ring problems.
Smoky
Like any engine, when assembled with quality parts, that are configured properly, it will be troublefree.
But when forged pistons are used in equipment that is improperly blueprinted or configured, disaster is likely.
That's not a fault of Wiseco, as much as it is a fault of the one who put it together. Measurements are necessary, and often times, adjustments.
I use Wiseco pistons in every 2 stroke I overhaul. I even used them in my Turbo Miata with 33 pounds boost. 177,000 miles can't be wrong! Proper clearances are a must.
But when forged pistons are used in equipment that is improperly blueprinted or configured, disaster is likely.
That's not a fault of Wiseco, as much as it is a fault of the one who put it together. Measurements are necessary, and often times, adjustments.
I use Wiseco pistons in every 2 stroke I overhaul. I even used them in my Turbo Miata with 33 pounds boost. 177,000 miles can't be wrong! Proper clearances are a must.
It would be interesting to know if the axial clearance between the rings and the lands were to spec. when assembled. I normally measure this, along with ring end gap, as well as piston and bore size (taper, roundness) for proper clearances even if the machine shop says its ready to assemble. That's just me, and I realize not everybody has the tools to do so. I don't want to have to repeat the process with torn up parts.
Piston to bore clearance doesn't have anything to do with this issue, but when changing piston technology, use the clearance recommended by the piston mfr. not the OEM clearance, they can be different.
As mentioned above, somebody may have just been using the wrong or improper bug fogging oil and carboned them up bad.
Piston to bore clearance doesn't have anything to do with this issue, but when changing piston technology, use the clearance recommended by the piston mfr. not the OEM clearance, they can be different.
As mentioned above, somebody may have just been using the wrong or improper bug fogging oil and carboned them up bad.
Last edited:
- Status
