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I have a 99 XC 700 SP with about 7,800 miles. I have owned it since new and have run Amsoil since approximately 3,500 miles.

Sled runs great and have been taken care of extremely well.

In general when do these 2 strokes need to be rebuilt? I have heard that the Polaris twin's are extremely durable and have quite a longevity. Aside from having it clutched the only other modification is a silencer.


Although is is running great I do not want to have a major breakdown in the middle of the winter. Should I be conerned about this?

1. What should compression be at?

2. How many people replace their water pump belts (how hard is it to get at)?

3. Any issues with oil pumps failing?

4. Clutch has about 5,500 miles on it. I had the sled clutched early on.

As I said earlier, the machine runs 100% perfectly. I am really not considering a rebuild this year but would like to have some idea of when it will be needed.
 

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"Good" compression should be around 120-150 lbs. As long as the crank seals are good, the crank has no up/down movement, and it doesn't have any knocks or raps, it's OK. Synthetic really makes a difference. The clutch shouldn't need it unless it starts to act up/not engage properly.
 

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5500 miles, your springs might be getting a little weak but thats about it. just clean the clutch, and check the weights to make sure they swing free.
 

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The weight bushings in the clutch as well as the weight pins are toast after approx. 2500 miles or sooner if they get rusted.
The spider button clearance will be out of spec also. If a solvent such as brake cleener has been used to clean the clutch than chances are the moveable sheeve bushing as well as the cover bushing are also in bad shape.
The clutch should be disassembeled and washed in HOT soapy water every season. Do not use any type of lubricant. Rust is the clutch's worst enemy.
Note: As the clutch wears the ballance changes. This will cause premature wear on the crank bearings. You will not be able to notice this out of ballance until it's to late.
As for the engine, a compression test will not show if the ring end gap is out of tollerance. If it is, you could catch a ring on a port and your day would be done.
 

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Frosty said:
As for the engine, a compression test will not show if the ring end gap is out of tollerance. If it is, you could catch a ring on a port and your day would be done.
A compression test will be able to tell to a point if end gap is excessive, because excessive end gap is caused by ring wear, thus changing the compression test.
 

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To change the water pump belt, you have to take off the recoil (that bottom bolt is a real pain), and then take off the clutch engagement basket and the belt slips right off. It is a pain but not terribly difficult.

If you have put 3500 miles on it and it wasn't changed before, you have your money out of that belt, I would definitely change it.
 

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if youve done typical maintanance on that thing and taken care of it while riding you shouldnt have to worry about a rebuild at this point. those engines can last.
 

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yeah. you shouldnt even have to worry about it until you about double those miles.
 
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