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Discussion Starter · #1 ·
I have to crack the throttle a little to get it to start after I stop to read a map or smoke a cig. Shouldn't it fire right up. My sons XLT starts one pull anytime after stopping. Anyone experienced this, I am sure it is something simple. I can tolerate it, I'd just like to know if I can fix it. Thanks
 

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Discussion Starter · #2 ·
Also, the longer it sits at idle it eventually idles down to about 800 rpm. Is that normal? Or, maybe related to the hard start.
 

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i have the same exact problem with mine and it buged the heck out of me.i beleave it is caused by being rich on low end i turned my air screws out 1/4 out and it helped it
 

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Most machines will start easier with a crack of the throttle. Usually when you're jetted fat, this is what's needed. If you have the carbs set perfectly for the conditions and have them syncronized very well, then this becomes less of an issue. But there is nothing wrong with this at all. Wheelers, bikes, even old cars start better when you give them a little throttle when they're warm. -Polaris Doc
 

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The idle is too low for your machine, it should be 1800 rpm. The service manual list the throttle gap and idle gap as the same for your sled which means the carbs may be out of sync or improperly synced (since the throttle cable sync process sets the stock idle on your sled. On most other polaris models it is a seperate step to sync the idles). Anyway, you should be able to just turn the idle screws in/clockwise to raise the idle and that will probably take care of the problem. Go slow, 1/16 or so of a turn at a time, then give the sled a while to see how it ends up idleing. I put a mark on my idle screws with a sharpie marker so I know how far I have moved them. When you turn the idle up by turning the idle screws it will probably help the starting becuase it is actually raising the slides the same as cracking the throttle. The carbs might be jetted wrong as well, like Polaris Doc said, and it may be worth checking them over. See if the idle adjustment helps first maybe. Here is the stock settings for your sled if you decide to re-tune the carbs:

1996 Ultra SP
Engine: EC68PL01
Carbs: Mikuni VM38
Main Jet: 340 (0 - 3000ft, -20f to +10f)
Pilot Jet: 50
Air Screw: 1 turn
Jet Needle: 6DH8
Jet Needle E clip: position 2
Needle Jet: P-4 (247)
Idle RPM: 1800

Synchronization:
-throttle gap: .187" (use 3/16" drill bit)
-idle gap: same (only 1 step sync process!)

As I noted, I have the service manual for your sled (and all 96-98 poo's.. yaaahh!) so if you have any other questions you can PM me or post on this thread.

seven
 

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Discussion Starter · #6 ·
All my jets are stock as posted. When I am riding and come to a stop it idles at 1800, then after a while it goes down to 800. When one says idle- is it immediately or after it sits a while? My carbs are synched. Also, the needle "E" clips on the second position- is this from the top or the needle end as I believe there are 5 positions?
 

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Discussion Starter · #7 ·
I may have my oiler set too high, it smokes quite a bit more than the XLT. I have it set just past the line. I am burning slightly rich.
 

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Between the 96 ultra, xlt, and xcr i've owned, the ultra smoked WAY more than the others. I had the pump leaned out some too and it still smoked quite a bit. Its just the nature of the beast on those sleds. You could run full synthetic to lessen the smoke, but it costs more. I had my oil pump on the ultra leaned out about a 1/16" without any problems. Not a whole lot you can really do on the ultra motor, they like their oil. -Polaris Doc
 

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The carb is well sync, that means that the slides up and down at the same time. For the WOT the carb should stop at same time, same place. As for idle, the idle screw will ensure that the carb stops at same place. Let it run idle, pull off and on the plug cap on by one and check the engines rpm drop. It is the same drop? Did you have a bogging issue when you launch the sled from a dead stop and putting it at WOT. If yes even if your jetting is stock, its little rich and making to have issue with idle. When you stop the engine and take a break you was running the sled so it moves, you let the carbs to give some gas in the case. After the break when you wanna go and start the sled, there's enough gas in the case to start it up, so if the pilot jet is getting and another amount of gas in the engine it will cause to make it harder to start. This is why its easier when you crack the throttle, you give the engine what it needs, air. I guest this issues mostly occurs at warmer temperature, isn't it?
 

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Discussion Starter · #11 ·
I am not fouling any plugs, my carbs are synched exactly the same everything. I still need to know if everyone considers the idle immediately after stopping OR after it sits a little while. Or should it stay the same regardless of how long it is at idle?
 

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Ideally you want an engine to idle properly right after stopping. There are other factors that play into this though. Lets say you get done with a long hard run and stop. Normally the engine will idle higher at first, then idle down after a bit. This is due to the engine and pipe being hot. Once it cools some, it will idle down. If you are idling high and it comes down on idle all the time, then you can remedy this by turning your air screws in about a 1/4 turn. High idle then coming down is more previlent on colder days when the engine is runnning leaner. It's not a bad thing, but can be annoying. Usually means your jetting is good and the sled is running well. I like my stuff to idle a little higher to keep it up on temp and to not load up with fuel. Sounds like you need to do something though if it's comming down to 800 rpm though. Idle it at about 2000. A little higher isn't going to hurt anything. -Polaris Doc
 

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My 97 Poo has an idle spec of 1600. When im riding and then come to a stop it idles at about 2300 for about 8-10 seconds before dropping down and settling in at 1600 (like Polaris Doc described). If your's is at 1600 initially then drops to 800 it is set too low. Play around with it, sometimes you have to ride a bit to see how the idle is gonna end up. If the sled is not fully warm it will keep idleing higher (at least mine does). Also maybe try backing your air screw out a bit (use your plugs and low - mid throttle/sled response as a guide). If you're a tad rich on the low throttle settings it can effect your idle. When I back my air screw out I have to turn my idle down. In fact after my rebuild, I had a hard time getting my idle set right untill I got my airscrew dialed in. Each sled is a little different.
 

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Discussion Starter · #14 ·
So, air screws out until idle stays up and if too high adjust my idle back down?
 

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to adjust air scews properly the idle should be around 1800rpm .so if its idleing down you need to raise the idle.get sled nice and warm first.start by turning all screws in and back out 1 turn. now start turning each screw out 1/8 turn .let idle stabilize .keep doing this till max rpm is reached.reset idle to 1800-2000 . all my sleds stop with a hi idle and drop to base idle after sitting.
i know you say your carbs are sync'ed,but if they are off this will do you jack! by the way the c-clip on the needle is 1 on top and 5 on the bottom. good luck too you.
 

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Discussion Starter · #16 ·
So, I adjust the air screws till I get the max idle they will allow. Then I adjust the idle screws till it is at 1800? Just curious also if I back off my oiler will it affect idle?
 

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you got it. it takes a good ear to hear the rpm change but you should get the hang of it. make sure you start with all screws at the same position
 

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Discussion Starter · #18 ·
Ok, I was going to adjust my oiler back a little, will this affect the idle?
 

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Discussion Starter · #20 ·
No, I'm asking if the lack of oil will affect the idle. (Because of more fuel in the mix)
 
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