Snowmobile Fanatics banner

1 - 20 of 21 Posts

·
Registered
Joined
·
2,731 Posts
Discussion Starter · #1 ·
I bought a 1997 xc 440 this last month. This has the Fuji-built XCR special motor with NiCaSil cylinders. compression is at 110 and 112 PSI (3 pulls, cold). had it running less than two weeks ago, luckily was taking a video of it. It was idling at 1000-1200 RPM. At the time, I didn't think the idle was bad, ran it on the stand, all was well. I don't remember if there was a bog when I gave it gas, but the video makes me believe that there wasn't.


Today, got it all fixed up (radius rod damage) and cleaned it with the powerwasher. Decided to run it once more. Had a hell of a time getting it started, but once it did, it hardly stays running. all signs make it seem like it is running on one cylinder. It is still idling at 1000 RPM, but it sounds bad and weak. Hit the throttle and there is a pretty bad bog as well, but once it's past the bog, it revs up just fine. But if we let it idle for a while, it would just die.

the mag side of the y-pipe is HOT but pto side is warm. Switched the plugs, it was the same deal. Both plugs have spark, and the plugs themselves is not the problem.

We then took out the PTO side spark plug and ran it only on the MAG side. It didn't start right away, it turned over and sort of ran and then died just like before.

Then we ran it only on the PTO side (with the MAG side spark plug out) and it acted the same way as it did running on the MAG side.

So it's running on the PTO side, just not as well as it should. So I have spark and I have compression. Cleaned the carbs, paying extra attention to the pilot screws and the needle/seats. There was plenty of gas in the carbs. Ran it again, same deal. checked the fuel line feeding the carbs, gas poured out of there too. So gas is getting to the carbs.

Checked the drain plugs at the bottom of the crankcase to see if its flooding, very minimal brown/clear fluid came out.

tomorrow I can take a video showing whats going on.

Any ideas of whats goinng on? or how to take care of the bog & low idle RPM? I realize it's summer and hot out, but two weeks ago it was running much better. The only thing that I have changed on the motor since then is the choke cables.

Again, the video posted here is from two weeks ago

View attachment 2010621183452812_23360.mov
 

·
Registered
Joined
·
2,786 Posts
Water in the system anywhere? Broken carb jets? What did the plugs look like? I would have to guess the PTO side carb jet is bent/broken/cracked or something along the lines.
 

·
Registered
Joined
·
2,731 Posts
Discussion Starter · #3 ·
I was extremely careful to keep the powerwasher away from the airbox and carbs. I would think water would make the sled not run at all, but it does- just can't idle worth a damn. The plugs weren't excessively wet, which goes along with hardly anything coming out of the drain plugs. So the motor isn't flooded. I have dozens and dozens of carbs laying around, if it comes down to it I can try other pairs. I'm wondering if this problem has something to do with the different choke cable, but the freeplay on the flipper switch is correct.... I guess As long as it gets running by winter when I sell it, I'm not in a huge hurry, but it would be comforting knowing it runs now.

tomorrow I'll have to ride it around the yard, see if the thing will even move with a load on it (ran it on the stand today)
 

·
Registered
Joined
·
2,786 Posts
Polaris_Parts_MN said:
I'm wondering if this problem has something to do with the different choke cable, but the freeplay on the flipper switch is correct....
I bet your choking the enging out. Try detaching the choke cable, and manually working the choke when it's idling.
 

·
Registered
Joined
·
6 Posts
Dragon700 said:
Polaris_Parts_MN said:
I'm wondering if this problem has something to do with the different choke cable, but the freeplay on the flipper switch is correct....
I bet your choking the enging out. Try detaching the choke cable, and manually working the choke when it's idling.
Hey I'm looking at buying a 440. I'm looking at a 96 xcr 440 and a 97 xc 440. What one is the better sled? I know the 97 has VES. Does it give the 440 that much more power?
 

·
Registered
Joined
·
915 Posts
If it has roundslide carbs I have seen the throttle cable come off the slide so it will idle fine but when you push on the throttle only one cylinder will rev and the other wont want to (if that makes sense) Just something you may want to check
 

·
Registered
Joined
·
46 Posts
Since you changed the choke cables it sounds like you need re adjust the chokes. One side is probably not fully seating. Loosen both locking nuts. Back both sides out till there is 1/4" or more free play at the lever. Tighten one side till the lever is tight. Back it out till there is 1/8" free play. Tighten locking nut. Repeat on the other carb. Should be good to go.
 

·
Registered
Joined
·
2,731 Posts
Discussion Starter · #8 ·
krisfrego said:
Hey I'm looking at buying a 440. I'm looking at a 96 xcr 440 and a 97 xc 440. What one is the better sled? I know the 97 has VES. Does it give the 440 that much more power?
'97 XC 440 does not have VES. This is the Fuji motor. the 1997 XCR 440 (rare sled, its more like a 1997.5) is the same as the 1998 "Red Rocket" which has the Liberty motor with VES.

But both 96 xcr440 and 97 xc440 are uncommon sleds. I would say try to find a 1997. both sleds have unique front suspension components (96 has "prototype" xtra-10, the 97 has "prototype" CRC xtra10), these parts are found only on those specific sleds. However the 97 is better because it has a remote adjustable resevoir for the rear fox shock.
Personally, I would stay away from both of these sleds. They are hard to find, and commonly are very abused and beat up because they are "race" sleds. I would suggest a 1997 xc 600 triple. same chassis, Xtra10 fox shocks all around. And 1997 monoblock triples had a 4th oil line to the PTO bearing solving the bad crank problems of earlier models. Not to mention for the same price as those other two 440's you can get a lot more power

fusionshuk06 said:
If it has roundslide carbs I have seen the throttle cable come off the slide so it will idle fine but when you push on the throttle only one cylinder will rev and the other wont want to (if that makes sense) Just something you may want to check
by roundslide do you mean the standard mikunis thats been on all Polaris sleds in the 1990s?
I've never seen or heard of that happening, but i doubt that is the problem because the motor's not idling fine to begin with. It sounds like its idling on one cylinder but running on two; but with a bad bog at take-off

Mhawk said:
Since you changed the choke cables it sounds like you need re adjust the chokes. One side is probably not fully seating. Loosen both locking nuts. Back both sides out till there is 1/4" or more free play at the lever. Tighten one side till the lever is tight. Back it out till there is 1/8" free play. Tighten locking nut. Repeat on the other carb. Should be good to go.
I still have the original choke I used two weeks ago, I will try using that again. (switched chokes because the old one has short cables so the flipper switch was by the steering post instead of over by the chaincase/muffler).
I looked in my repair manual and it also said freeplay should be between 1/8" and 1/4" and thats where it was at when I put the new choke cable on, but I can adjust it anyways so I know it's correct.
 

·
Registered
Joined
·
1,016 Posts
Ive had, and seen the throttle cables falling off on roundslides, which were standard on most polaris sleds from the 80's-90's. They do fall off from time to time if the retaining washer thing isnt in the correct space. If you can get it running, try to spray some starting fluid or carb cleaner in between the clutch and block and make sure that seal is good! It sounds to me like it could be getting too much air, or just choking itself out. We had a sled that would cold start great, run great for about a minute, then be really hard to keep running. Turned out the choke cables fell off the lever.
 

·
Registered
Joined
·
9,987 Posts
If you just hold it at partial throttle, will it keep bogging? If so, then hold it there for a few seconds then check the plugs.
 

·
Registered
Joined
·
2,731 Posts
Discussion Starter · #11 ·
Ugly_old_Poo_kid said:
If you just hold it at partial throttle, will it keep bogging? If so, then hold it there for a few seconds then check the plugs.
no, It's only bogs if I give it a lot of gas.


I also checked the PTO crank seal and carb boots today, they are fine.
This morning it started first pull, and idled at 1500 rpm, But it still had some bogging. Check the Y-pipe, both sides were hot, with the MAG side only slightly hotter than the PTO. Here's the first vid, you can hear it bog at 1:30 and 2:13
http://www.youtube.com/watch?v=DPY5pdbcDwA



Then I tried to adjust the choke cables, moved the choke up and down the whole threads and the freeplay never changed. But it sure screwed up the motor. Ran it again, Idled at 1000 RPM, with a really bad bog- like a 3-4 second delay when I pinned the throttle. This video you can hear it bog at 21 & 24 seconds, and then it bog really bad from 34-37 and 41 to 44 seconds.
http://www.youtube.com/watch?v=IgebKqwFwUg



I tried using the choke I used two weeks ago, made no difference. Tried a third choke cable, started and Idled at 1500 rpm, revved it up and then it idled at 1000. This last video shows the throttle position when it bogs.
http://www.youtube.com/watch?v=xhG-QUFFUQQ
 

·
Registered
Joined
·
46 Posts
Mhawk said:
Since you changed the choke cables it sounds like you need re adjust the chokes. One side is probably not fully seating. Loosen both locking nuts. Back both sides out till there is 1/4" or more free play at the lever. Tighten one side till the lever is tight. Back it out till there is 1/8" free play. Tighten locking nut. Repeat on the other carb. Should be good to go.
origionally posted by Polaris_Parts_MN said:
I still have the original choke I used two weeks ago, I will try using that again. (switched chokes because the old one has short cables so the flipper switch was by the steering post instead of over by the chaincase/muffler).
I looked in my repair manual and it also said freeplay should be between 1/8" and 1/4" and thats where it was at when I put the new choke cable on, but I can adjust it anyways so I know it's correct.
The lever can still be at 1/8" free play if one side is adjusted right. The other side can be way off. The free play is determined by whichever side is tighter. I still think one side isn't seating. Do the plungers still look good?
 

·
Registered
Joined
·
1,016 Posts
Is it just too warm to run a L/C?? It ran pretty good in the first vid when it was cold, and worse later when it was warm. Sometimes they run much better in the winter with snow, just saying.
 

·
Registered
Joined
·
2,731 Posts
Discussion Starter · #14 ·
Yes, I know they aren't exactly made to run in summertime. But two weeks ago it was running much better than it is this week. Not to mention my other two Liquid-cooled sleds are running just fine this week.

And yes the plugs on all the choke cables look good.
 

·
Registered
Joined
·
2,731 Posts
Discussion Starter · #15 ·
tried riding it today; simply put, she's not going anywhere fast.
walking alongside it, she went less than 5mph at 4500 RPM at almost WOT.
I guess I'll have to dig through my box of choke cables until find a pair (or I bet a set from a triple will work too) that is already adjusted to the right freeplay
 

·
Registered
Joined
·
3,063 Posts
Polaris_Parts_MN said:
tried riding it today; simply put, she's not going anywhere fast.
walking alongside it, she went less than 5mph at 4500 RPM at almost WOT.
I guess I'll have to dig through my box of choke cables until find a pair (or I bet a set from a triple will work too) that is already adjusted to the right freeplay
Why not just adjust the ones you have?
 

·
Registered
Joined
·
634 Posts
^^ good call. try adjusting the set you have before you go tearing it all apart 40 time just to change choke cables. Im having kinda the same issue with my wifes 94 xlt sp. Same bog but not as bad. haven had time to dink with it yet though.
 

·
Registered
Joined
·
2,731 Posts
Discussion Starter · #18 ·
I already tried adjusting the choke, and only made it worse.
Fixing sleds is a hell of a lot harder than tearing them down
 

·
Registered
Joined
·
634 Posts
LOL agreed but its alot of fun imo. besides how else are we gona learn anything if we dont try
 

·
Registered
Joined
·
46 Posts
Are you sure you adjusted them the right way? If you did then I doubt that they are your problem. Switching them won't make a difference.
2010626133630998_32916.jpg
 
1 - 20 of 21 Posts
Top