brokenparachute

stock piston or wiseco. benefits/risks?

kccats

I use Stock Type pistons with skirt coating when ever possible! Some times you can't!

DoubleClutch

SPI make a good teflon coated piston and I haven.t had an issue with them in my ss440 engine in 2 years. Wiseco pistons cost more and are pron to cold seazing in some engine's. I also have used numaura pistons and been happy with them allso.

__________________
01 Yamaha SXR 700
82 Polaris TXL340 (Oval racer)SOLD
80 Yamaha Exciter 440
79 Yamaha Exciter 440 (Oval Racer)
78 Artic Cat Pantera
72 Polaris Colt 295 ss F/A

Country Road Cycles
Motorcycle-Atv-Snowmobile Repair.
http://westernpasnowmobiler.com/foru...fad3dfa1b281c2

600RacerX

Depends on what you're using them in. But for the most part I'd say an OEM grade Coated cast piston would be good.

musicfreako

I have rebuilt countless Snowmobile engines with nothing but coated spi pistons. Love them! I will not use weisco pistons in a two stroke Snowmobile engine.

__________________
The only cat I'll ever own will have a track and not require a litter box

Current rides

98 ZR600 EFI (03 zr900 skid, reverse, fox shocks, clutched)
97 Polaris Indy 500 (stock)
91 El tigre EXT 530 (01 Zr skid, clutched, MINT)
94 Polaris Indy trail deluxe (very heavy!)

New rides
90 El tiger EXT 530
98 Zr 600 Carb
00 Zr 600 EFI (trophy winner in the 700 class drag races)

indyryder500

weisco pistons are made better then they were in the past. but stock is good.

__________________
97 ultra spx slp can geared clutch and 144 studs.(mine)
96 XLT studded with reverse(12y/o son)
98 xcf 440 (wifes sled)
96 puma 340 elec start(kids sled)
96 cougar 550 2up bone stock (sold)
96 XCR 440 clutched (sold)
92 indy 500 bored,clutched. piped(sold)
85 indy 400 (11 y/o son's sled)(sold)
87 yamaha excel 340 (parting out)(sold)


2011/2012 miles :00000000

smokingcrater

I use wiseco's... I'm also smart enough to not hop on a sled and let it rip, which is how they got their reputation. People forget about how important a little warmup time is.

__________________
1) 2000 Arctic cat ZR 700, which now thinks it is a 2001 ZR 600 EFI APV w/136" ripsaw. (for sale!)
2) 1995 Yamaha VMAX 600, which now thinks it is a Polaris! (Polaris x10 suspension, Polaris P85 clutch) (for sale!)
3) 2004 Yamaha Warrior
4) 2006 Yamaha Nytro

musicfreako

I'm smart too...

I always let my machines warm up.

__________________
The only cat I'll ever own will have a track and not require a litter box

Current rides

98 ZR600 EFI (03 zr900 skid, reverse, fox shocks, clutched)
97 Polaris Indy 500 (stock)
91 El tigre EXT 530 (01 Zr skid, clutched, MINT)
94 Polaris Indy trail deluxe (very heavy!)

New rides
90 El tiger EXT 530
98 Zr 600 Carb
00 Zr 600 EFI (trophy winner in the 700 class drag races)

catfan

I am a fan of SPI pistons will use them over standard or weisco any day.

__________________
My toys

Arctic cat
1991 Prowler m/c 2up 440
Polaris
1973 Charger 400
Ski doo
1997 MXZ 440
1996 MXZ 583
X3 1970 Olympic 335
1967 Olympic 247
1967 Super Olympic 300
John Deere
1973 John deere 400
1974 Columbia 340
Parts pile
X2 1972 polaris charger 400
1975 JDX8

polaris_5257

X3 on the spi pistons they are great

Sent from my Droid using SnowMobile App

Roof_991

X4 on the spi and for the price u can't go wrong
Sent from my US740 using SnowMobile App

jwaldmann89

Are all SPI piston's single ring designs?
I've used Weisco before, haven't had any problems.

__________________
2004 F5
2004 Yamaha R6 Powercommander

polaris_5257

No I've put spis in my ultra, prox 2, and even my 1200 watercraft motor and all were 2 ring pistons


Sent from my Droid using SnowMobile App

catfan

All my SPI's where dual ring setups also. never have had a problem with them.

__________________
My toys

Arctic cat
1991 Prowler m/c 2up 440
Polaris
1973 Charger 400
Ski doo
1997 MXZ 440
1996 MXZ 583
X3 1970 Olympic 335
1967 Olympic 247
1967 Super Olympic 300
John Deere
1973 John deere 400
1974 Columbia 340
Parts pile
X2 1972 polaris charger 400
1975 JDX8

smallengineguy

If factory pistons had one ring, the aftermarkets will. Forged pistons expand quicker than cast, and are more finicky. If you let the machine warm up, either type is good. Although unless you're running super high compression or nitrous, forged is overkill IMO.

__________________
1992 Ski Doo Mach 1 (SC-10/2 suspended) March '07 SF.com Sled of the Month! (Lost in fire 4-13)
1992 Ski Doo Mach 1 original
2006 Ski Doo MXZ 500SS

Webmaster Evergreen Valley Snowmobile Club
SledNH.com Moderator

jwaldmann89

The only reason I was asking about the duel rings is becuase my friend rebuild his 99 Zr600 with SPI and the piston's only had one ring on them? Odd...

__________________
2004 F5
2004 Yamaha R6 Powercommander

musicfreako

That engine is a dual ring design. Sounds like wrong application or they were a low compression design intended for blowing or Nos ...

__________________
The only cat I'll ever own will have a track and not require a litter box

Current rides

98 ZR600 EFI (03 zr900 skid, reverse, fox shocks, clutched)
97 Polaris Indy 500 (stock)
91 El tigre EXT 530 (01 Zr skid, clutched, MINT)
94 Polaris Indy trail deluxe (very heavy!)

New rides
90 El tiger EXT 530
98 Zr 600 Carb
00 Zr 600 EFI (trophy winner in the 700 class drag races)

jwaldmann89

Yes I know it's a two ring engine, hence why I said "odd." the parts store we bought them from told us that's what he needed.

__________________
2004 F5
2004 Yamaha R6 Powercommander

Roof_991

Im going to have to say the parta store messed up on that one


Sent from my SCH-I500 using SnowMobile App

69CRUZR

depends on the engine type. If the engine is a cast iron sleeved cylinder I would not run the Wisecos. If it is a nicasil (spelling?) coated aluminum bore then I would not worry about it. Aluminum heats up and expands MUCH faster than iron, and the cold seize syndrome is way more common in those engines, where a guy starts it lets it idle long enough it wont die when he slams the gas, and goes screaming wide open across a field. The pistons expand faster than the bore and it seizes up!

With the nicasil coated bore the metals used in both the bore and piston are certain alloys of aluminum, and will have a much more similar expansion rate, I chose Wiseco for my Liberty 600 after lots of debate about this exact same topic.

__________________
1998 Polaris XC600 (with a XCR sleeper hood on it)
2006 Polaris Indy 500
1969 Chevy C10 "69CRUZR"
-383 stroker 450 hp 479 ft lbs of torque

2006 Chevy Colorado -daily driver


----------------------------

New Project Truck, this one for my Pops!

1953 GMC 5 Window Shortbox Stepside

Drivetrain: 2006 5.3 Liter v8 with 4l60e from an 06 Silverado.

Full IFS front suspension kit w/rack and pinion steering, and 4 link rear from TCI Enterprises.