Anybody had any problems on their Polaris 400 engines with piston skirt breakage??? I just got off the phone with Rick Ritter of RCR, and he said that the best thing I could do to increase the reliability of my Xplorer 400 was to change to a Wiseco piston, and that the stock piston was pretty much crap. I went ahead and ordered a piston, rings, and gasket set, along with an oil injection elimination kit, but I'm wondering how many of you have had this problem. I don't know if I'll install the piston yet, but I'm curious as to how widespread the problem is. I don't doubt Rick's statement that he sees alot of broken piston skirts, but I just want to know who all has had this problem. Thanks in advance!!!

Waylan

 

Personally i know of one 93 350 two wheel drive 6200 miles on it took the piston and crank case out.

 

Normally Wiseco pistons are a lot less durable than stock pistons. Throw aways designed from moto to moto. Call and check around with other "Polaris Specialists" to make sure Rick just did'nt want to line his pockets a little more. Good luck!

 

Rick is NOT like that !

 

It might be hype, but I put in a Weisco also on my Scrambler. Darrel over at HPD told me to do so and so did a lot of others. Darrel does not do port/engine work if you do not take the Weisco. Maybe he knows from experience that the stock one will not hold up to all that extra power.

 

Even the local polaris dealer said that he see's the skirts break a lot. My 93's never had a problem but I might have been lucky.

 

Walexa,

I beleive the stock piston is jsut as good if not better that the after market. The reason for the skirt breakage is simple. Many people buy a 2-stoke with out fully understanding the differnces between the 2-stokes and 4-strokes. It has been my experience that the rings on a 2 stroke do not last as long as those on a 4-stroke. I have personally seen many people on the trail that have severe piston slap. Of course, the rings are worn. They still have good enough compression to run but really need to be freshened up. Then eventually the skirt shatters and ends up in the crankcase causing more damage. AND, the blame goes to the stock piston.

Just my opinion, but what do I know. I am no Rick Ritter.

Greg

 

Since I made this post, I've talked to a good friend of mine who races motorcycles. He said that through the years, he's had stock piston skirts break. However, he said that he always puts a Wiseco Pro-Lite piston in his bikes now, and has never had any problems. He said Wiseco pro-lite pistons were tops, and that is what Rick Ritter sold to me. I talked to Rick again to confirm that it was a pro-lite piston--and Rick informed me that is all Wiseco makes for the polaris 400. Rick is also going to throw in a used stock 400 piston, along with a used Wiseco piston for me to compare the two before I replace my stocker. Rick said that he orders crank cases 3 at a time, due to the number that get trashed by broken skirts. It is costing me $135 for the new piston, rings, and gasket set. I also ordered the oil injection block-off kit. When I asked Rick about eliminating the oil injection, he stated that he had more faith in the oil injection than the stock piston. He did, however, claim that an engine running on pre-mix would last longer than one run by injection, even without injector failure. This is due to a more even distribution of lubricant in the fuel. With injection, you can get good life, but lubrication will not be as good as with premix. I'm wanting to set my bike up for the long haul, and this is the reason behind eliminating injection, along with going to the wiseco piston. I hate tearing into an engine that has had only 3 tanks of gas run through it, but I believe it is the right thing to do for me. I can either pay a little now, or a boat load later. All I'm paying for is some insurance. I love this quad and plan on keeping it for a long time.

 

.... are you just changing pistons as preventive maintenance?

(IMHO, if it ain't broke don't fix it, you could be voiding the machines warranty)

The 378cc Fuji engine is very durable in it's stock configuration. We have had three of them in the family and never had a piston problem in over 7,000 combined miles.

But... there are those that cannot resist the urge to run a theoretically optimum main jet and ....then things begin to get interesting.

Remember a 2 cycle engine will always produce the most horsepower it ever did, right before the rings stick and the piston seizes due to a lean fuel mixture. Be careful

 

Thor,

You are correct, I'm changing pistons as preventative maintenance only, along with going to premix over the injection system. As long as I use a torque wrench, and take my time, I don't mind the piston replacement. This action is the same as eliminating the oil injection: as long as it's working, you should be fine. However, if the oil injection goes out, you're looking at pretty big bucks. Same with the piston: as long as it works, great. However, I imagine that the cases are pretty expensive to replace, and that would require motor removal. I've got to get a good torque wrench before the piston and rings get to me. Anybody know a good economical brand? Thanks.