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Discussion Starter #1
Wifes sled is a 97 Jag 440. While reving it up on the stand, it bogs when you first punch the throttle. You have to feather the throttle until the rpms are high enough for the clutch to engage and then the response is good. It only happens when you raise rpms from an idle. Gas is good, carb is clean, and I changed the main jet from 310 to 300. Any other suggestions? Need to get it fixed cause wife is threatening to take my sled for the winter if hers isnt fixed.
 

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<BLOCKQUOTE id=quote><font size=1 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>Originally posted by tvan:
Wifes sled is a 97 Jag 440. While reving it up on the stand, it bogs when you first punch the throttle. You have to feather the throttle until the rpms are high enough for the clutch to engage and then the response is good. It only happens when you raise rpms from an idle. Gas is good, carb is clean, and I changed the main jet from 310 to 300. Any other suggestions? Need to get it fixed cause wife is threatening to take my sled for the winter if hers isnt fixed.


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It has been my experience that this is usually the carb(s) not being 100% clean. Every nook and cranny must be cleaned with carb cleaner, including removing the idle and main jets and blasting those circuits out, then blasting out the jets, themselves. If the jets don't get perfectly, squeeky clean, replace them (to avoid too lean a mixture). As a general rule, if you didn't use a good 1/2 can of carb cleaner per carb, you didn't use enough...

Anyone else???

1998 Arctic Cat Cougar
1999 Arctic Cat Z 440
1995 Ski Doo Formula STX LT
 

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The belt maybe??...

GO HARD, OR GO HOME - IF YOU COME TO A FORK IN THE ROAD...TAKE IT
 

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Sounds like water in the gas to me, or some sort of moisture problem. Floats sticking maybe. Might wanna put your old main jet back in though, it really wouldent have an effect on low rpm engine problems. The main jet starts pumping at the end of the throttle, low to mid range is still pilot and needle jets.
 

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Well guys heres how i see the situation.

1. Its not the belt because he is describing the situation when you punch the throttle till the clutches engauge. So the belt unless it is too tight would not be the problem.

2. If the floats were sticking the sled would run horrible either at idle or WOT, which is not the complaint.

3. Fuel pump should be fine if sled runs good at high speeds, because this is when the fuel demand is higher.

4. I kinda doubt the Jetting is the culprit here. If the sled hasnt done this before then its not in the size of the jets.

Im still leaning twards a carb problem here though. What i would check is to make sure the choke isnt partially stuck open or has the cable improperly adjusted. Also make sure the e-clip on the needle is in the correct position. Make sure the air screw is set at 1.5 turns out +/- 1/4 turn. If a twin carb setup check the sync of the carbs. It could also be possible for bad needles and seats leaking just enough to cause too much fuel at idle. This is just my two cents worth on the matter, take it for what its worth. Hope this helps a little.

Polaris is my way out - Other people just use a door.
 

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Ok, TriumphoverU, that post is getting printed and put in my sled file for future reference!

What a wealth of knowledge we have on this site!

Jacqui.
 

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I will bet any money that the pilot jet is plugged. If the sled will idle, and once up and running run fine, but then when your stopped and you give it some gas it bogs, its most likely your pilot jets. Take the carbs off the flanges, turn them over, take off the float bowls and with a very, very small screwdriver, take out the pilot jet that is located in the small round hole (tunnel) on the side of the main jet. Find a piece of stranded electrical wire, like that from your wire harness on your vehicle, and take one strand of wire and poke the center. Then blast it with some carb cleaner and your in. How do I know this? Many years of knowlege, and it happening to me more than once.

'HAMMER DOWN !!'
 

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<BLOCKQUOTE id=quote><font size=1 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>Originally posted by jacqui583:
Ok, TriumphoverU, that post is getting printed and put in my sled file for future reference!

What a wealth of knowledge we have on this site!

Jacqui.


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That's why they call him The Sled Guru

Trees don't make the greatest brakes.
 

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Discussion Starter #12
Thanks for all the advice. After reading all the replies I am going to concentrate on the carb. Will start with adjustments and work my way to the inside. Will let you know what happens.
 

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Hey he should have Erick or ProX-man change his title to "The Sledy-Lama"
T-man....you always seen to cut through the shop talk BS, and tell it like it is.

Sorry bout the new nick name PolarisMan, I am just excited for you to get your new sled, can't wait to see pics of you on it, makes me think I could buy a brand new sled some day.

 

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Just want to add my .03 cents worth. (inflation) I have solved many a problem like you are talking about with a simple adjustment to the air screw.If this does not work, I feel the problem is either an obstructed pilot jet. Or an obstructed pilot air passage.Or More likely a blockage in the Idle bypass passage, the mixing chamber or the main idle passage. As a side note. I have cleaned more sets of carbs than the average joe, probably in the hundreds over the years and I never found the need for the use of carb cleaner. Disassemble completely. A dip in any shop type solvent and a thorough blow with compressed air. Works for me.

Reasonable people adapt to the world around them....Unreasonable people try to change it.
 

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i just rebuilt the carb on my 440 jag now its a 440, with a single 34mm carb, and it runs a 280 main jet , the 300 is the stock size used for break-in, way too rich, so i assume that your following the temp, alltitude jetting specs, if you have, id say first off put new plugs in , also clean the air filter, if this still dosent work, id say play with the air screw, go like 1/16 of a turn at a time and try it until the throttle is crisp, good luck

if its not a CAT, then it must be a dog!
 

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Discussion Starter #16
Sled came with a 310 main. Dropped to a 300 because it was to rich. Didnt want to go lower because I didnt want it to be to lean.AC dealer told me that I should put the 310 back in if temp goes below 0 otherwise it will be to lean.Sound right?
 

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<BLOCKQUOTE id=quote><font size=1 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>Originally posted by tvan:
Sled came with a 310 main. Dropped to a 300 because it was to rich. Didnt want to go lower because I didnt want it to be to lean.AC dealer told me that I should put the 310 back in if temp goes below 0 otherwise it will be to lean.Sound right?


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Yes there right... if the slow jet isnt your problem the needle can make a huge difference in the way a engine runs. I have dirtbikes and we changed the needle jet and it makes a huge difference off idle and makes the engine snappier everywhere.
 

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Me being a moto-x racer I'm always adjusting my jetting. Start at the basics!! get the carbs in-sync. If they are off no matter what you do it'll run crappy, especially at low rpm's. The adjustment for the off idle is the air screw (which fine tunes the pilot (slow) jet) Set the AS at the stock setting and go in 1/2 turn incriments on BOTH carbs. YOU CANNOT ADJUST THE CARB BY RUNNING IT ON THE STAND!!!! You have to ride it!! If the bog gets worse go the other way and eventually you'll find a setting that is right.

The needle position affects 1/8-3/4 throttle and the main jet is 3/4 to WFO. Changing the MJ will not have get rid of an idle bog and the needle position will primarily help a midrange bog

Win if you can...
Loose if you must...
But NEVER stop trying!
 

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Discussion Starter #20
Got rid of the bog...Took carb apart and cleaned it out..didnt look gummed up though and pilot jet was clear. Cleaned it out though. Put back together and adjusted air screw and choke. Runs like a champ. Dont know exactly what fixed it though. Thanks to everyone for the advice. It was extremely helpful. Wife now gets her sled back and I get mine.LOL
 
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