kick starting feels like no compression?

hi there,

my son tells me tat recently when he kick start his 98 wr4, it feels like sometimes there is no compression?

he has been riding it for the past 1&1/2 yrs wif only frequent oilchanges,

maybe a top overhaul is in order,

iszit a difficult task for a weekend warrior to do?

thanks. :)

Check that the decompression cable is not binding in the open release postion. I think that the WR400 had a decompression cable on the handle bar. :)

I've experienced the same problem twice. The first time, the bike was extremely flooded. Not sure how that contributed to the problem, but that's just what I noticed. The other time was after I chaged to yz timing, and did not do it correctly. The timing was way off, and the exhaust valve was opening at the wrong time. The other possibility, as Dan mentioned before, would be the decompression cable is hanging on something (in the open position). The lever is on the bars. Make sure the cable is lubed sufficiently, and that the free play is correct.

How many time have you noticed this problem? has it increased immediatly or a little, ride by ride? In adittion to other advice, I suggest you to check valve clearance and piston rings wear. If the problem were piston ring wear, the bike would burned a lot of oil.


I would also look at the decompression actuator on the head. Pull the decomp lever in and watch the actuator when you let the cable out to make sure it is not sticking.

thanks for all the input,


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