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08 XCF 250 hard to start

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Have new to me a new bike.  Bike has about 50 - 60 hours total on it.  Prior owner about 20 hours ago put factory 280 cc kit on it.  Power is awesome but when I ride bike and it gets hot its really hard to start.  Actually two issues: I think most of the time its hard to start because maybe I need to adjust jetting and possibly valves.  But if valves needed adjustment (they were last done when 280 kit was installed) wouldn't that make it hard to start when cold too? Jetting was pretty good but I added Fmf megabomb and 4.1 silencer.  I had to turn out fuel screw a lot to get it to not backfire on deceleration (almost 2 full turns).   (That's why I think I need to play with jetting but nothing major.)  Been riding a 2 stroke for a lot of years so this is new to me.

 

As far as the second problem, when electric starter battery dies and I try to kick it, occasionally its close to top dead center (just a guess based upon feel) and its almost impossible to depress the kicker.  Its seems like it has compression lock up.  After practically standing on the kick arm lever, it usually releases and kicks normal.  I know the bike does not have automatic decompression but is this normal?  Am I hurting the bike?

 

I have heard that big bore kits can compound the compression issue.  I really like the power but am thinking I should go back to stock cylinder.  Would this help?  Your thoughts?  Thanks for your time, Steve

 

 

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usually the FIRST sign of tight valves is hard HOT starting as you describe.

 

Adjusting the fuel screw to MASK a decel pop now has your low end jetting screwed up and may contribute to the hard start. The KTM pipe system has air leaks and they decel pop. Enrichening your fuel screw only masks the problem and makes your bikes jetting wrong.

 

The auto decompress may have an issue or broken part. I have a 300 kit on mine and it isnt that hard to kick. I also have never had the battery run down so I wonder if its time for a new battery for you?

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Forgot to mention. Bike just got Dirt tricks auto cam tensioner. If that is not working right or incorrectly installed would that cause engine to act like its seized? Kick lever was very hard to depress at first then released.

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Probably your jetting expecilly if you put a pipe on it. You should jet it when you do that anyway. But check jetting first(easier+probably cheaper)

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I would check your jetting, if it's still stock buy a JD jet kit.  Contact James at JD and he could tell you what jetting you should be running with a 280 kit.

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I suppose it may be possible but not likely to have the chain get off time when changing the tensioner. That could make the compression stroke, valve opening timing off and make it hard to kick and turnover. Maybe take of top cover and check valve timing marks.

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Thanks everyone.  I changed the oil over the weekend and found a few large pieces of metal in the oil.  Not just the typical "metal fir" but more like wood splinters.  Thinking more and more that something related to replacing the cam tensioner might have caused something to go wrong.  Definitely going to take top cover off and check valve timing marks and go from there. 

 

I still will have jetting issues but I am more concerned with why so much metal in the oil.  Thanks, Steve

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