A few questions regarding engine hours

7 replies to this topic
  • silentZ

Posted May 02, 2011 - 08:49 AM


my engine hours are getting pretty high on my 08 450.

Yesterday at the track i noticed radiator fluid on my left boot, coming from the overflow tube. Not a whole lot, and the radiator is topped off. Is this normal?

Also, at 207 hours on the bike I am starting to think that I need to have some work done.

The bike fires up first kick when hot and about 4-5 kicks when cold.

I am concerned that the timing chain has reached it's limit.

I also want to get a new slip on exhaust, (still running the stock one) but I want to make sure that my engine is in top shape before attempting any sort of increase in power.

Any recommendations?

  • KJ790

Posted May 02, 2011 - 09:23 AM


If you have gone 207 hours without changing the timing chain then it is possible that you could have some big problems. That is the weak link on these engines and stretches pretty quickly, once stretched it will begin to wear out the sprockets it rides on, of which one is made on the end of the crank shaft. Do yourself a favor and change the cam chain immediately and look at the sprocket on the end of the crank. If that is wiped out then you will have to replace the crank shaft.

When was the last time you checked the valve clearances?

  • grayracer513

Posted May 02, 2011 - 09:25 AM


I would definitely replace the timing chain and do a valve clearance check before pulling the cams.

As far as the coolant on your boot goes, you need to verify that the coolant is not coming from the impeller shaft escape port, the "weep hole" in the right crankcase cover below the water pump. If it is, it means the impeller shaft seals need attention.

  • silentZ

Posted May 02, 2011 - 09:46 AM


The valves were checked about 40 hours ago.

The fluid I believe is coming from the breather hose, not the radiator overflow hose as I previously mentioned. It's the hose near the left oil drain bolt and curves outward.

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  • KJ790

Posted May 02, 2011 - 09:50 AM


Are you sure it is coolant coming out? If you overfill the oil then a little oil will come out of the breather tube, especially if the engine is worked hard. Coolant should never come out of the breather tube unless there is a major problem.

  • grayracer513

Posted May 02, 2011 - 10:21 AM


I've had my port and starboard crossed up all weekend. The left boot would be getting oil from the breather. To an extent, this is normal when you run the engine hard, but it could also be an indication that the engine is in need of new rings if it's something that it just started doing. That, or you overfilled it.

  • silentZ

Posted May 02, 2011 - 10:57 AM


Thanks so much for the info.

I think I have a plan of action.

  • crf450319

Posted May 02, 2011 - 11:10 AM


I'm with the other guys though, for the cost of a cam chain you won't do any wrong by replacing it.

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