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elivingston199

yz450 shows no signs of starting at all. need help

9 posts in this topic

just got a yz450. needs some work has coolant and oil leak but wanted to make sure it at leasts starts up first. gets spark, carb is clean, gets fuel, timing spot on. wont bump or kick start at all maybe 1 small pop after a long time. what shoul I check. I just got it for a good deal and I don't want to dump a lot of money into it. I already have other bikes and don't need this but it would be fun to have

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Are the valves shimmed to spec? Had a friends bikes in the past with spark and fuel with good timing. Would kick forever with maybe a pop or two. I finally got a feeler gauge inside the head and valves were way out. Also, what year?

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its a 2004 sorry and idk i never checked valves. i had terrible experiences with a crf in valve adjustments in the past

 

dont need to adjust it if you arent comfortable but checking their gap is foolproof. Just align the hashes and pull off the gas tank and cylinder head cover and check. random questions, have you tried a different plug?  Hows the compression have you had it checked? 

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yup atleast stick a feeler gauge in the valve so you will atleast know if they are even in the ball park.. also compression tester would be a good idea.  you can rent one from a parts store usually for free.. how did you check the spark on the plug?

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Conventional compression tests are a fairly complete waste of time on a singe cylinder engine with auto decompression.  If you're going to test, a leak down test in far more useful.

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t check the spark  on the plug i took the plug out, put th boot on the plug grounded the plug and kicked it over and i didnt check comperession bt there is compression there  

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t check the spark  on the plug i took the plug out, put th boot on the plug grounded the plug and kicked it over and i didnt check comperession bt there is compression there  

 

if you can check timing you can check valve clearance. You dont have to do the work if they are out but its worth a shot. take the cover off line up the cylinder and TDC and start sliding the feeler gauges in and write them down.

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