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Discussion Starter #1
I just replaced a blown 1996 Polaris XLT 600 engine with another one that same year. I have spark and the plugs look wet. The compression looks good about 120 psi in each cylinder. What else can I do? It almost started but stumbled. Any suggestions???[V]
 

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make sure its to use starting fluid with cyl lube in it...Sounds like it might be flooding???
 

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Either has no lubricant in it.
Use WD-40, it's very flammable and will lube pistons.

Sounds to me like old fuel, is it?

If so, dump it and put in new stuff.
 

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Are the carbs off your engine or the did they come on the new engine.

Check the Choke Plungers to make sure they function and are set correctly, check the float tabs to make sure they are level, clean the carbs (especially if they came with the engine, double check all the fuel and air lines. Definetly sounds like your getting to much gas. Also as suggested make sure to get fresh gas and using starting fluid CAN damage your engine so i wouldnt recommend it. You shouldnt need to use anything if the carbs are correct. My XLT pulls on the first pull or second pull everytime (even after sitting for the summer). Also throw a new set of plugs in. Your compression is fine.
 

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Discussion Starter #7
Well, I was able to start it yesterday one time after many pulls(20+). The engine does seem to have been flooded. It did run for about 5 minutes with a good idle, no spuddering, although the idle did seem low, 1200 rpms. Is that a good idle rpm? I was not able to get it started again. The engine would not come close to starting with the choke on. I did check and clean the carbs from the old engine. They seemed clean and I blew out all of the ports on the carb. I checked the floats and they did move freely. I don't know if the floats are set correctly. I did change the plugs and noticed that the plug close to the pull start was becoming brown, the other two were still clean after putting in new plugs. I did replace the caps from the old engine. Is it possible that the air screw is set incorrectly, I set it at 1.5 turns from fulled closed? I will try new fuel as the fuel has been sitting for 5 months+. I will try to drain the tank today and fill with new fuel. Thanks for all of the input.[?][|)]
 

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when it doesnt start are the plugs wet??? I would also say your needle not seating properly..
 

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Discussion Starter #10
The plugs are not really wet, but do smell heavily on fuel. How can I check, adjust the carb needle? I didn't notice them to be dirty or gummed up.
 

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Not the jet needle.....the needle n seat. It is what allows fuel to flow into your carb. As the fuel comes into the carb throught the seat the fuel raises the float. Once it gets to the proper level the float tang pushes up on the needle to close off the seat. If its worn, fuel can continue to leak in, and eventually drain into your cylinder. This would then produce a hard starting situation due to flooding.

You could pressure test them, but chances are they haven't been changed in a while, and even if this doesn't turn out to be the problem, I'd still recomend changing them. They aren't very expensive either.
 

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Those XLT's don't like the choke. If you get it started once in this warm weather you probably shouldn't have to use the choke again all day. But you might have to give it a little throttle when you pull. Lots of good advice from the other guys.
 

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I believe 1.5 turns is correct on the air screw. You should raise the idle to the previously stated 1800-2000. as far as the floats being correct what you should look at is the metal piece that the floats push up into. You should make sure that the tabs are level. If it doesnt start after fresh gas i would agree with the other replies about replacing the needle and seats. Things can "look" just fine in a carb but be very far from fine. Did you check to make sure the choke plungers are functioning and set correctly?

Aren't three carbs fun... This is the reason i like my twin's...
But my XLT sounds so much better... so i guess it's worth the trouble.
 

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Discussion Starter #15
Can someone please post a photo of a needle and seat on the carb. I am not clear on what needs to be replaced. Thank you.
 

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Here ya go, print this off....

http://www.mikuni.com/pdf/vmmanual.pdf
 

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Discussion Starter #17
Well, I did change the needle and seats with not much change. It did start 1 time after 20+ pulls. I was not able to get it started again. I tried another set coils and CDI box with no luck. I am tired of looking at this snowmobile in my garage. Any input would be appreciated. Thankx.
 

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Well, you say you're getting spark, the plugs are wet, and now you've changed the needle n seats as well. Assuming the floats are set to the correct height, the next thing to make sure of is that the throttle cables, and choke cables are set to the correct specs, and are synced. VERY important! If the chokes sealing properly, this would also cause a flooding condition.

After these are checked and set, I'd look into the timing, check the stator. Also be sure your pistons are where they're suppose to be when the plug fires. If your crank is spun (out of sync) this would throw your timing off as well.

Just throwing out some suggestions at you. Process of elimination. Keep letting us know what you find out.

Oh, one more thing. If it is flooded real bad, you'll want to open up the three 10mm bolts in the bottom front of your crank case. They're below each of the exhaust ports. This will allow any exess gas to drain out of the case. If that's full of fuel, it will never start.
 
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