Hard to kick (issue with decompression?)

I have a 2004 CRF 450 that was always easy to start until the valves zero'd out. I put SS kibblewhite, and I also re-ring my Wiseco piston. I also "played" with the decompressor arm clearance, but made sure that I was eventually in spec (0.011 + 0.014) ... The bike fired up first kick BUT the compression is WAYn higher than it was before. It almost xlike the decompression is not working. Is it due to the stronger KB springs, new rings on the piston, did I mess up somehow the decompressor arm clearance ???

I would bet you are off one tooth on the timing!! Mine was the same way and then rechecked the timing and it was advanced 1 tooth.

Bike started first kick and runs great ... just that it is hard to kick "compressionwise".

Bike started first kick and runs great ... just that it is hard to kick "compressionwise".

again, check the sticky at the top of the page on timing marks. Also make sure you check your measurements on the decompressor arm.

My timing is correct,all marks line up perfectly, valve clearance is in spec ... bike fired up first kick but compression is way higher than before hence really hard to kick. As for the clearance on the decompressor arm, I believe that I did it right (insert a 0.011" feeler gauge at right EX, then set clearance at 0.014" on the decompressor arm) .... am I missing something?

on the 04, it is easy to unhook the spring for the decomp throwout weight. it's on the brake side of the cam shaft, and when you pull the valve cover off, the sharp end of the thin spring can hook on the gasket. pull the cover off, and see that the decomp arm is being held in lightly by the thin wire spring. if it is off, the weight will flop back and forth at even kick-start rpm's.. and not actuate the decomp..

by "hard to kick", i assume you mean like literally standing on the kick starter your worrying it will snap off? lol.. i have had this occur. impossible to do on later years with the newer decomp design, but trickier to reassemble when putting the camshaft gear back on..

MELK-MAN very good piece of information, I'll definitely check this out ... in a few days (I had ACL surgery yesterday so I am laying in the couch right now). Thanks.

On a bike that old the timing chain has likely stretched to the point that the timing marks line up but it is off one tooth. Take the spark plug out and put a screw drive in (make sure the handle is big enough that you cannot drop it in) to find a true top dead center. My guess is that the timing marks don't line up any more. Chain stretched on my bike for this exact thing to happen.

Two options if that is the case. Replace the timing chain which is recommended, or use the screw driver method to find TDC.

I ran my bike for 2 rides untill I realized that the timing was out 1 tooth etc!!!!!! Will run fine but just be harder to kick etc. It throw the decomp timing out more than it seems to affect how it runs.

I will definitely also double check the timing. Thank you to all for the suggestions :-)

On a bike that old the timing chain has likely stretched to the point that the timing marks line up but it is off one tooth. Take the spark plug out and put a screw drive in (make sure the handle is big enough that you cannot drop it in) to find a true top dead center. My guess is that the timing marks don't line up any more. Chain stretched on my bike for this exact thing to happen.

Two options if that is the case. Replace the timing chain which is recommended, or use the screw driver method to find TDC.

this could be the case, but not likely due to the fact his symptom came up AS SOON as he did some work on the bike. My 04 had HUNDREDS of hours, this isn't something that occurs overnight. his issue did.. so something happened during the time he was working on the bike.. IMHO

this could be the case, but not likely due to the fact his symptom came up AS SOON as he did some work on the bike. My 04 had HUNDREDS of hours, this isn't something that occurs overnight. his issue did.. so something happened during the time he was working on the bike.. IMHO

Reread his post. He changed valves. Cam and sprocket have to come off to do that. If the chain was stretched and he disassembled without checking the location of the timing mark and then put it back together assuming the chain had not stretched the timing would be off one tooth. The exact thing happened to me.

MELK-MAN very good piece of information, I'll definitely check this out ... in a few days (I had ACL surgery yesterday so I am laying in the couch right now). Thanks.

15 days after ACL reconstruction: off crutches, and walking normally. Doing actually so well that I worked on my bike today:thumbsup:

I ran my bike for 2 rides untill I realized that the timing was out 1 tooth etc!!!!!! Will run fine but just be harder to kick etc. It throw the decomp timing out more than it seems to affect how it runs.

I thought that the timing was right because the bike started first kick, albeit hard to kick ... but GTXR was right: timing was indeed out 1 tooth. Reset timing, and bike started first (easy) kick (with the good leg:smirk:). Thanks to all.

Good to Hear you got her back together right!! Now get that leg better and hit the dirt!! LOL>.

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