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99 400 2 stroke smokes after carb rebuild

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Old Aug 23, 2009 | 10:30 AM
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Default 99 400 2 stroke smokes after carb rebuild

99 polaris scrambler 2 stroke-

I replaced, jet needle, valve needle, pin, floats, float assembly,plunger, etc. It ran great for several weeks. Couple weeks ago, it starting emitting more exhaust smoke than normal. It also lacks power on initial takeoff and stutters. I noticed that the carb intake box is oiling up and the carb itself has oil over it. I use polaris gold 2 stroke oil, so the smoking is quite noticeable

What do think wrong? Thanks- Nick
 
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Old Aug 23, 2009 | 08:09 PM
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are you mixing the oil yourself?
also does the air filter require any oil on it?

did you check the reeds while you had the carb off?
 
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Old Aug 24, 2009 | 12:13 AM
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It sounds like you are still using the oil injection?

Have you checked your plug?.... How's it looking? (specifically)

Look to see if you have a leak where it pumps into the intake.
If not, go throught the injection pump adjustment proceedure.

If that gets you nowhere, you may want to drain your tank out into a large clear container and see what you have.

If you see nothing, take a small can over where you get gas for it at and get a gallon to test for ethanol.


Also, drain your counterbalance oil, to be sure it is not contaminated or over-full.
 
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Old Aug 24, 2009 | 05:38 PM
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No, I am not mixing my oil and I did not check out the reed valve. Probably should have checked the reed valve but I rebuilt the carburator because I was losing power on the initial takeoff and there was no smoking. I would think it could possibility be the reed valve, but will check others areas before I go further. I do appreciate your input though and thanks
 
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Old Aug 24, 2009 | 05:56 PM
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Yes, I have checked the plug, but this was before I rebuilt the carb. I haven't check it since, but with the smoking, I am fairly sure that it will indicate too much oil.

I will check the oil intake and go through through the oil injection procedure.
The fuel I am using has not given me any problems as I use it in other small engine devices.
Not sure why I should check the counter balance oil, I do not take it through high water, although it is a good maintenance procedure and I will look into it as well.

I am real suspicious that I screwed up somewhere in my rebuild although it worked great for over a month. Don't suppose it has something to do with the choke.
I did replace the plunger.
Before I replaced the plunger, I did not have to use the choke to get it started- not even after setting for a week.
Now, after setting for a week, I do need to to use the choke to get it started.

Do you suppose the problem lies there?

OR could it be the reed valve. I did not see any where in the manual that a defective reed valve could induce the smoking problem. I appreciate your input and if you have any ideas, please let me know. You should note that I do not abuse the unit, It is just used for utility and casual riding around the property.

Again- thanks for taking the time...

Let me know if you have any other ideas- Thanks
 
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Old Aug 24, 2009 | 08:54 PM
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Compression check!!!!!
 
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Old Aug 24, 2009 | 09:50 PM
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Originally Posted by Nick Danger
Yes, I have checked the plug, but this was before I rebuilt the carb. I haven't check it since, but with the smoking, I am fairly sure that it will indicate too much oil.

I will check the oil intake and go through through the oil injection procedure.
The fuel I am using has not given me any problems as I use it in other small engine devices.
Not sure why I should check the counter balance oil, I do not take it through high water, although it is a good maintenance procedure and I will look into it as well.

I am real suspicious that I screwed up somewhere in my rebuild although it worked great for over a month. Don't suppose it has something to do with the choke.
I did replace the plunger.
Before I replaced the plunger, I did not have to use the choke to get it started- not even after setting for a week.
Now, after setting for a week, I do need to to use the choke to get it started.

Do you suppose the problem lies there?

OR could it be the reed valve. I did not see any where in the manual that a defective reed valve could induce the smoking problem. I appreciate your input and if you have any ideas, please let me know. You should note that I do not abuse the unit, It is just used for utility and casual riding around the property.

Again- thanks for taking the time...

Let me know if you have any other ideas- Thanks
Sounds just like what I went through, with a few exceptions...

1- I premix now

2- I actually had fuel leaking out the overflow, which got to the point I had this problem, and had to rebuild the carb too.

My fuel eat up the rubber tip on the needle enough that it couldn't seal against the seat. So my bowl overflow issue kept getting worse....

My bike was like it was flooding a little and rich everywhere, and also hard to start at times... when it had none of these issues before.

Getting some gas I know is all gasoline, dropping to 87 octane, putting in a plug, and installing a new needle and seat took care of me.



Your counterbalance oil is important because it will no run as well over-full or if the 4 stroke oil is leaking through to the 2 stroke side...

And it gets over-full either by you overfilling.... or by your water pump seals or gasket leaking coolant into the CB oil (BAD). Yes, the retards put the water pump IN there... and that is where it will leak to.

So it is a good idea to check the level... and a good idea to drain ALL of the drain points at least once any time any issues crop up.

You want to make sure coolant is not making it's way into either side of the case.... one side would contaminate your CB oil and take out your bearings.... the other side would be putting it in with your air/fuel charge I guess.

CB oil leaking over to the crank would cause loss of CB lube, and put 4 stroke oil in your air/fuel charge.
 
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Old Aug 25, 2009 | 06:31 AM
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Check your antifreeze level also, I just did a complete motor for a buddy on a '99 Scrambler, he was complaining of it smoking more than usual, found out the seals to water pump were shot and antifreeze going straight into counter balancer area. You should be able to smell antifreeze burning, and wetness at the end of silencer. Wasn't a pretty picture once the cases were split, ended up doing crank bearings, seals, and counter balancer do to grooves at end of shaft
 
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Old Aug 25, 2009 | 11:59 AM
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Originally Posted by uncertifiedmechanic
Check your antifreeze level also, I just did a complete motor for a buddy on a '99 Scrambler, he was complaining of it smoking more than usual, found out the seals to water pump were shot and antifreeze going straight into counter balancer area. You should be able to smell antifreeze burning, and wetness at the end of silencer. Wasn't a pretty picture once the cases were split, ended up doing crank bearings, seals, and counter balancer do to grooves at end of shaft
Exactly right... and I need to ask you some questions too, so check your messages...
 
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Old Sep 1, 2009 | 06:43 PM
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Originally Posted by uncertifiedmechanic
Check your antifreeze level also, I just did a complete motor for a buddy on a '99 Scrambler, he was complaining of it smoking more than usual, found out the seals to water pump were shot and antifreeze going straight into counter balancer area. You should be able to smell antifreeze burning, and wetness at the end of silencer. Wasn't a pretty picture once the cases were split, ended up doing crank bearings, seals, and counter balancer do to grooves at end of shaft
Well, I checked the "counter balance" and the oil was milky white. Poured a half quart of oil through it to flush it out. Checked the exhaust and it was damp. I checked my carb boot (attached to the air box) and it was compromised. It was allowing outside air to come through a gap. Ordered new boot and want to see if that was the culprit in regard to the smoking. I do have it in mind to get the seals replaced but would rather wait until winter hits. This must be a fairly common mechanical failure in these units. Anyone else have similar situations? Thanks for information. Will let you know outcome. Nick
 
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