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Discussion Starter #1
I just finished rebuilding my 1995 650 rxl. I blew out a piston skirt last year and decided to bore out all 3 cylinders .20 over with new pistons and rings. After assembling the motor, my son pulled it over and noticed that it was quite a bit harder to pull over. It doesn't feel like anything is sticking or stuck. I oiled everything down real good before assembling it and put a small amount of Polaris injection oil in each cylinder. Will going .20 over incrrease the compression that much? I'm going to take a compression test tonight when I get home. It just makes me a little nervous that it is that much more compression or is that much harder to pull over. The pistons, rings and cylinders could have been real worn before, but I'm not sure. Anyone have any ideas? Thanks in advance for any comments or help.
 

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Went through the same thing with mine last year. Motor would start 2nd pull every time and you could pull it over with 2 fingers on the pull cord. Lost a skirt intake/mag side put a fresh top end on it and compression was noticably different even had to re-clutch ! It was just that wore out in my case.
 

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Thanks sportnut. I thought it may have been something that I did wrong on the rebuild. Did you have to bore out your cylinders and if so how much did you go? Its just hard to believe that mine pulled over so easy before and now its substancially harder. I hope to start it this weekend.
 

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Standard bore just a hone Weisco Pro-lites pistons. I think if this sled was carbed it would have never started it was tha wore out . Bought the sled used so I believed they just pulled over that easy. At .20 over with stock gaskets tou shouldn't have any problems I think you just went through the same thing I did.
 

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When I rebuilt my RXL I could barely pull it over the first pull. Not until after I primed the oil injection did it really loosen up. So keep pulling it will be fine, but this won't raise the compression at all.
 

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Discussion Starter #6
Thanks for the responses. I was a little bit concerned because I remember how easy it pulled over last year vs now. I primed the oil injector and will try to start it this week. Thanks again for the info.
 

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All fresh rebuilt motors are harder to pull over. I just rebuilt my YZ 250 motox bike and I can barely kick it over. It wasn't easy before but not its got alot more compression.
 

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Not to hijack your thread but whats with all the 650 motors on e-bay all the time? Theres always 3 or 4 complete motors going for very reasonable prices. I will be riding my first 650 this winter retrofitted into a later project sled. Have heard nothing but good things from them. No crank issues, they warm up to pipes nice and sound killer. The abundance of realatively cheap parts prices is another bonus.
 
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