Dan-Senior said:I had the 97 Super Sport and here is what I did. 1.) Installed thin head gaskets which raised compression to 143 psi. In doing so, you need to cool the engine, so installed a shield ($3 cooking sheet) between the muffler and fan intake. Also punched open all front vent holes on the cowling (directly behind the bumper). Removed the front bumper. 2.) Bored the carbs. 3.) Grinded weights on primary clutch and installed higher engagement spring. 4.) Re-wound secondary clutch with more tension. 5.) Heat wrapped the exhaust pipe just after the "Y". 6.) Changed gearing from 21-39 to 20-39. By doing steps 1 to 4, your rpms go up considerably. So even though the 20-39 in theory is 5 mph less, the increased rpm of the engine offset the drop in speed and actually moved this sled into the 90+ mph range. A totally different sled once the mods were all done. Also installed plastic skis to lighten up the front end. Have fun! Those are great sleds. BulletProof.
what kind of head gaskets did you use? were they stainless? i think that a guy could contact cometic gasket and get a set of multi-layer stainless gaskets made for this purpose.... how long did that motor last?
Keep it cleaned and tuned. Maybe bore it a few over[only if you're already in the state of tear down]. maybe reeds or exhuaust but the minmal gains for the money would not likely be worth it. The best bang for the buck will be in carb jetting and clutching. I have a 488 and they're only designed to do so much. It's an economy sled with reliability in mind. Stay away from ethanol where possible and use fuel treatment if you do use it, and quality plugs and belt make a difference too. I melted two engines in the name of squeezing out performance. These engines are known to be "bullet-proof" but only within certain parameters. Have a REPUTABLE mechanic tune and jet your carbs. Don't mess with 'em unless you really know what your doing. I hope this helps. If you want a real upgrade for not a lot of money trade up to another sled. Say something like an older XLT, XCR, Ultra, or a Storm. They're out there for reasonable prices.jtb0322 said:I currently am riding a 97 indy 488 supersport and im looking for some mods. I've been looking at some mods but i need some help. Anyone have any ideas for my sled? PLEASE HELP!!
Don't bother shaving or grinding the weights, your best bet is to just get a new primary spring with a bit more engagement, and a stiffer secondary spring with a more aggressive helix than the stock 34 degree one that they came with, spinning more RPM's is not gonna make it any faster, gearing down will make it a bit slower on top but it will get to top speed quicker, spending money on trying to get more HP out of a 488 fan is like trying to sell a chocolate ice cream cone to a lady with white gloves on a 90 degree day, if you want more power then its time to upgrade to a bigger cc sled or at least move up to a liquid cooled 488 Indy 500, I owned one of these sleds, bought it brand new in the fall of 96, rode it for one season, put 1600 miles on it and the very next spring I snow checked a 98 XC 700 and never looked back, the 488 fans are what they are as explained by a few other posters, its a white bread and butter type of sled, clutch it, jet it (if needed) and ride it.jtb0322 said:What exactly should i do to the clutch? How should i shave the weights?
34mm roundslidesjtb0322 said:Can anyone tell me what size carbs are on my sled? They are mikuni carbs but i have no idea what size?! PLEASE HELP!
No benefits there either, putting air filters on in place of the stock air box will just cause more problems than its worth, especially on that sled, we've already pretty much explained what you can do to make it perform better, clutching,jetting and possibly gearing, anything other than that your just wasting your time,mind and money.jtb0322 said:Would new aluminium intakes with built in filters help by eliminating the airbox and allowing more airflow? How much of a difference would this make?