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Discussion Starter · #1 ·
Ive got a 98 indy 500 i blew up end of last riding season, ive got it comletely torn apart one piston is completely toast. just owndering if anyone has any good suggestions on what i should do. i would like it to be faster but dont wanna spend a ton. bore it? performance pistons? any suggestions would be great. also how do u get the damn piston pins out they dont wanna come out at all and yes the clips are out.
 

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check this out ya never know?

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3633014461&category=26354

New Wiseco SK1064 piston kit for Polaris 500 liquid cooled engines. Kit includes 2, standard bore (72.00 mm bore) pistons, rings, wrist pins, circlips, and top end gasket set. Fits the following models: Indy 500 1989-03, Indy 500 Classic 1989-02, Indy 500 RMK 1996-99, Indy 500 SKS 1991-97, Indy 500 EFI 1992-97 and Indy 500 Classic Touring 1999-03 models
 

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There have been problems with Wiseco pistons in the past. They would distort and stick in the bore. If that is still an issue with them I would stick with the Polaris pistons. You can buy them either 10 or 20 Th. oversize. Any competent machine shop should be able to bore your cylinder for you.
If the pin won’t come out by tapping with a hammer and a pin driver you may need a piston pin puller. You can buy them in most parts catalogs.
Good Luck
 

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To remove the piston, just get a hacksaw and cut off the connecting rod, then stick it in a press and press out the piston. Then weld the connecting rod back together.


If you want it to be faster, I would put it back together and get a clutch kit.


[:D] Just kidding, don't follow that advice.

As for wiseco pistons, I've heard they cause lots of trouble, I'd go with Polaris pistons.
 

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I had to rebuild my 96 Indy 500 after 8,000 hard miles. The pistons started to break apart. Chunks came out from between the ring grooves. Fortunately I was using synthetis oil & was able to limp home the last 35 miles of a 600 mile weekend. The bore was damaged above the exhaust port on the mag side so the block had to be bored & honed. Polaris OEM pistons were a cast piston, OK for easy cruisisng, not good for hard riding. Weisco forged pistons were the most economical route for me so that's what I used. I ran the sled one more season with no problems. Sold the sled. The following year I did the same rebuild to my Dad's 96, 500 Classic. Presently both sleds are running fine. I am not endorsing Weisco pistons. I am saying that in these two instances they worked OK.
 

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I have a '98 Indy 500 and rebuilt it this summer as at the end of last season I was experiencing some problems. I ended up boring it out 20mil since there was too much slop in the pistons, and put in a new piston kit. Believe it was a Kimpex not Weisco - did this due to price and heard they were comprable.

I also put in an EPI clutch kit and rebuilt the primary as I believe that was what was causing my grief last year - bogging at mid range. I fully cleaned the carbs down to the last screw - although they were spotless to begin with.

For fun I also replaced the black fuel line, as heard it deterorates overtime, and replace antifreeze, and flushed the brake fluid as well.

Itching to find out how it will run this year, will let you all know how the clutch kit works. That seems to be the first thing anyone recommends on this page when doing mods so figure that's where I'd start. The bore out I decided to do only after I took off the head off to look at the pistons. Not expected much extra hp from that, although I've noticed its improved my compression considerably.
 

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get a couple spi pistons,gskts,rebore, and FIND out what caused it to blow.BEFORE running it again,was one plug white on the bad piston,likely partially plugged main,then then run it as is.make a piston pin puller with some threaded rod and a socket.
500,s run forever with a little maintanace.
 

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RE: Wiseco's.

If your the type of rider who likes to just pull the cord, and rip away, wiseco's arn't for you. They are MUCH more sensetive to bore/piston fit. Cast (OEM) pistons can take more abuse in this respect.

Forged pistons require that the block be up to a resonable operating temp before you get on it, because the piston will expand very quickly as it heats up, and the bore expands slowly... Picture a cold block, a dude hammering on the throttle. Now watch as the piston grows, and then does a 4 corner siezure in the block. That is the most common occurance with wiseco pistons.

I have put on roughly 1000 miles on my sled since installing wiseco pistons.

And yes, the most important thing, is NOT to fix the symptom, FIX the disease. Find out why it burned down in the first place. Otherwise you will go through pistons like underwear, and that gets expensive!

-Dean
 

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Wiseco is all I use in my race motocross bike and sleds. I constantly bounce the motors off redline w/o issues. But I have everything profesionally plated, bored, and honed with a piston/cylinder clearance of .002" (on the bike at least)

Pistons aren't ever-lasting parts and they will self destruct with excessive mileage/abuse
 

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Discussion Starter · #11 ·
thanks for all the help i am going to put in a set of wiseco pistons. well see what happens.
 
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