I have a pretty lightly used (2800 miles) original engine 1995 Polaris Indy 500 XLT 500 triple. I had no problems with it up until last year. It began to be really difficult to start and would not idle. So I first attempted to adjust the carbs with no good results, then dismantled them for cleaning and inspection. I that two of the choke plungers were stuck in place which would explain the hard starting and stalling at idle. It would run fine when up to speed.
So, I installed a new choke cable, cleaned the choke passages, carbs and jets. Problem solved right? Well, it did solve the stalling at idle and difficulty starting. Now the problem I have is that it won't idle below 4k...meaning it's like it's stuck in that position. I have read that bad crank seals could be one possible cause. I don't think that is it because the problem began right after I had worked on it and the plugs are not showing a lean condition at all. I did notice that the throttle cable is stretched and I have slop at the throttle cable. I ordered a new throttle cable and am waiting for it to arrive. I also have the carb idle adjustments at their lowest setting and it didn't help. I drained the tank, put in new fuel and have cleaned the carbs twice. This is a very frustrating problem, help is appreciated!
Where are the air screws adjusted to? If you have them too far out, that can cause a lean condition. I would still check the PTO crank seal and check all the carb boot adapters for leaks. Use some starting fluid, WD40, even carb cleaner. Spray the fluid around the pto seal and boots with the engine idling. If you have a change in idle, there's a leak. If not, you will have ruled that out.
I would also make sure that all the needles are inserted into the needle jets properly. With the idle screw all the way out, there shouldn't be any space between the carb body and the bottom of the slide. Check for easy up and down motion in the slide, there could be some debris or slide galling that is hanging up one of the slides.
Yes, it's actually the 580 motor....I am kind of new to working on snowmobiles, it appears I had the idle screws mixed up with the mixture screws...doh! So the slides were not going completely down. The stretched throttle cable could be problematic. I am waiting for the new one to come in the mail. So it will probably be a week or so before it's back together. Then I need to try to sync the carbs and adjust the choke, both of which I haven't done before. Thanks for all the help, will let you know how it works out.
Finally put it all back together and it's running great so far! Apparently it was a combination of a worn and stretched throttle cable and I had the idle screws on the side of the carbs set incorrectly. I was going by the info I read to start at 1.5 turns out from bottom, if I set them there it will idle way too high, I have them probably out a bit past half way. I am pretty sure I have the carbs synced and the chokes set properly, but will keep an eye on the plugs for any sign of problems. It took me forever to figure out this problem, but I saved a ton of money in repair costs and learned a lot too! I found a new throttle cable online for $23 bucks, a dealer down the road wanted $150!
Thanks for the help you guys, I really appreciate it.
Ok, it runs great once it starts but is difficult to start cold, once it's warm, it starts with just a turn of the key. It could be the chokes, I am not sure they are adjusted exactly right, but I know they are seated so flooding is unlikely. The other reason I don't think it's the chokes is that today when it was 38 degrees out, I started it, ran it for a while, then when I tried to start it about 3-4 hours later it was as difficult to start as when it was cold.
I have the idle set to where after it idles down it idles good at about 2k...I tried adjusting it lower then it idled down and died, so I went back up to 2k at the low end. But the idle problem seems intermittent. I just put in non-ethanol gas as I read that it vaporizes easier, making a machine start better cold. I can live with the idle being a bit high, but the hard starting issue is a PITA. Help!
Now today at 36 degree temp it started right up and idles fine at about 2k....I have ridden it maybe an hour, pulled the plugs and they are all three a nice light tan color and each cylinder has a compression of 90 psi. So it appears I can move on to the next project. Thanks for all the help!
If your compression gauge is accurate, 90 is still a bit low. I would test your gauge on another engine or compare the gauge to another one to see if it's reading low. Most of the time, if a 2-stroke dips below 100 psi it's time to redo the top end...
Watch those crank seals! My friend just blew up his 94 xlt 580 about a month ago because the pto crank seal went out and took out the piston on that side. I would've never guessed that was going to happen because it ran so good before that although the idle was a bit strange.
Well the idle is fine now, so I doubt the crank seals are bad. I just need to dial in the chokes a bit more and hopefully it will start easier.
I am not sure about this compression gauge, I just bought it at the Infamous Harbor Freight tools for about 30 bucks. I also used it on my old 340 Yamaha and got 45 and 60...so when I tested the Polaris it initially read 60 lbs with the screw in rubber hose extension, then I used the one you just press and hold and it read 90 lbs...I think the gauge is a POS and will likely return it next week and buy a good one.
Both of the sleds run good with excellent top end power, so I doubt that compression is an issue. Luckily I have plenty of time to tinker.
If you've got an air compressor and a blow gun with a soft tip, you could check the compression checker by pressurizing it off the compressor. Not exact by any means, but you should know if it's off 10psi or more. Harbor Freight is definitely a crap-shoot; their stuff should work most of the time, but will let you down eventually. I'm pretty sure a lot of no-name tools sold in parts stores, HF, Wally world, etc. are just about the same thing though, most of them probably even made in the same factory. So you're right to doubt the low reading, especially if the cylinders match up pretty closely.
It's running really well now and starting easier too, so progress is being made. I broke the tip off the temp sending unit, it's in a poor location and while trying to adjust the idle, it's in the way. I would like to replace it with an actual temperature gauge instead just a warning light, plus there is a perfect spot for one on the right side of the dash panel...one the same size as the fuel gauge would be perfect. Anyone know of an aftermarket one that will work? One designed for a car would probably work although not sure if the sending unit would screw into the existing threads on the head?
I've seen after-market temperature sending units with gauge that fit in one of the radiator hoses... you can find them at pretty much all the online parts houses. I like Dennis Kirk...
Thanks. Another question...I am trying to dial in the idle and it seems to start better cold if the idle is set higher. Right now it idles cold at about 3k, then drops down to just over 2k. I tried lowering it to specs (1,500?) making sure that I adjust all carbs equally, and then it was difficult to start. Could be somewhat related to the electric starter which is beginning to fail. Will it hurt anything to have a bit higher idle?
Still don't have the chokes exactly right so that could be causing hard starting as well.
Have about 3' here in north Idaho...cold use a bit more. Another question, I am going to clean the chaincase and change the fluid. I have read that a lot of people us Amsoil the achaincase oil and many use ATF...I want to purchase the Amsoil and will be in Spokane.Wa tomorrow, anyone know which major (or small) retailers might carry it?
Ok, forget the Amsoil, too expensive, I might run it if I had a newer sled. I have been reading a lot about chain case oils and 2 stroke oils, and my head is about to explode and I'm more confused than ever. I have 1995 Polaris XLT 600 triple (yes finally figured out which engine, lol) with about 2900 hundred miles on the original engine. Always used standard blue 2 stroke oil so can't see going with synthetic at this point.
Then I have a 1998 Arctic Cat ZL500 with about the same mileage. The previous owner said it had been rebuilt, so no idea how many miles are on the engine. I have been using the same standard mineral oil based 2 stroke oil in it also. Going to change the chaincase oil, not sure what to use. Trans fluid or chain case oil? Synthetic or regular?
I use the stuff from the dealer on my Cats. It's about $8 for 8oz. There's a lot of theory over alternatives; I'm sure you've seen them if you've been googling. For me, $8 isn't that bad. Granted, it's pricey, but I'm sure I've sunk more into less over the years. Peace of mind knowing it's the right stuff and it'll work in the chaincase.
You can also use SAE30W [non-detergent] oil.
Thinner oils are recommended for use with the "silent" chain used in most sleds now since it will penetrate the links.
So, use what you want and if cost is a factor, go cheap.
I decided to order some Klotz chaincase oil for the Cat at About $9 for 12 oz, I value the 'Cat a bit more so decided to spend a bit more, plus I figure I can probably get by with changing it a bit less often.
For the Polaris I have some Polaris chain case oil leftover from when my Dad owned it, so I have enough for one fluid change. After that I will probably use Type "F" trans fluid. I just think that gear oil is too thick, especially in colder weather.
In my Dad's old '78 Yamaha Enticer, I will definitely use ATF.
I have been using the blue mineral 2 stroke oil and will probably continue to do so for right now. I bought a gallon Castrol snowmobile oil today for $20. Next I might try the Mystik Sea and Snow semi synthetic oil, I found it close by at Ace Hardware, also for $20 per gallon.
For those older sleds without exhaust valves you can use any oil that TC-W3 rated.
I use "Super Tech" from WalMart @ $11/gal.
Been using it for many years in all my sleds.
Thanks. What year did snowmobiles become equipt with exhaust valves and power valves?
Anyone know where I can order or buy a temperature sending unit with a splitter connection so I can hook up a mechanical temp gauge and still keep the idiot light connected?
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