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camshaft question - crf 450 - video - please help, riding tomorrow!!

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ok guys, I just rebuilt my engine. its been 6-8 months since I last touched the bike so im kinda forgetting how it feels and what its supposed to sound like.

im pretty sure ive gotten everything together properly and cant remember if this is normal or not.

ive rotated the engine over a few times by hand on the kickstart, and the sounds/feels it seems to be making just dont seem right to me, I could be wrong though.

once the cam lobes roll over the intakes, it stops for a second. then it takes no effort to kick it over, it just flops upwards about 45 degrees like I show in the video. this is very hard to describe. hopefully the video helps you understand what im talking about.

its 7 o clock and all ive got to do is put the cylinder head cover on and see if shell fire... I dont want to start kicking it like a mad man just in case I have something wrong. could someone here PLEASEEEE help me as im supposed to ride tomorrow!!

thanks a million!

heres the video... watch these points and turn your sound up: 0:14 - 0:18 and 0:34 - 0:40

http://www.youtube.com/watch?v=75R6OqQu4hE

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It will build compression and get tight then loose as the valves open to let air into the cylinder. Try pulling out the plug and it should get smoother until the cam lobes make contact with the rocker arm and lifters. Double check your decompressor is working correctly. Triple check your timing using the 2nd mark on the flywheel for best alignment, and you should be good to go.

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It will get hard to turn as the piston comes up making compression. once it passes top dead center it will turn easy so it looks ok in the vid, not like being there though.

the click is the decompression pin.

As long as the timming marks are lined up. if nothing is hitting goin slow, I think your fine, go for it. :thumbsup:

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It will build compression and get tight then loose as the valves open to let air into the cylinder. Try pulling out the plug and it should get smoother until the cam lobes make contact with the rocker arm and lifters. Double check your decompressor is working correctly. Triple check your timing using the 2nd mark on the flywheel for best alignment, and you should be good to go.

yes, there is LOTS of compression with the plug in. its also a stage 2 cam which im sure doenst help... but im just very very concerned on those points I mentioned in the video (0:14 - 0:18 and 0:34 - 0:40). it seems like the cam just flops upwards, I cant remember if this is normal as I havnt touched the bike in nearly 8 months

It will get hard to turn as the piston comes up making compression. once it passes top dead center it will turn easy so it looks ok in the vid, not like being there though.

the click is the decompression pin.

As long as the timming marks are lined up. if nothing is hitting goin slow, I think your fine, go for it. :thumbsup:

yes im 99.9% sure that the timing marks are lined up... ive taken this engine apart 4 or 5 times now so ive got timing it pretty down packed. its just that part where it flops concerns me... im going to go attach the head cover and gas tank and see if she fires. got my fingers crossed, hopefully I dont damage anything or up for sale she goes!

thanks

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just got back from the shop and....

it started after about 15 kicks!!! first time ive heard it run in a very long time. I cant wait to ride tomorow. thanks guys!!

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yes im 99.9% sure that the timing marks are lined up... ive taken this engine apart 4 or 5 times now so ive got timing it pretty down packed. its just that part where it flops concerns me... im going to go attach the head cover and gas tank and see if she fires. got my fingers crossed, hopefully I dont damage anything or up for sale she goes!

thanks

Report? I'm betting the timing was off?

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Report? I'm betting the timing was off?

nope, timing is dead on. bike starts and runs fine. I used to be unsure about my timing, but ive done it so many times ive got it pretty simplified.

1. line the crank timing mark up (right side of the bike).

2. I know approx how the lobes on the cam go... they point up and back a little bit, so I spin the cam so it looks like that. that makes the cam sprocket holes very close to where they should be.

3. then I line the lines on the sprocket up with the triangle marker on the cam assembly, this gets me very very close to perfect timing.

4. adjust the cam so the sprocket holes line up with the sprocket

5. put chain around sprocket and bolt it on!

hardest part I find is torquing the cam sprocket bolts properly :thumbsup:

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just got back from riding... bike rides awesome and very strong :thumbsup:

few complaints/problems though.

sometimes it started first kick easily.. sometimes it wouldnt start at all and it was VERY frustrating. very very frustrating. I tried with choke on/off, gas on/off, hot start on/off and nothing. I had a friend help push the bike half way up a hill and I bomb started it and it started very easily with a bomb start... why is that?

also, I used to be able to just keep kicking and kicking, without finding TDC, non stop. but now if I kick fast and hard the kick start (or engine!) seems to lock up or something, and I have to let off the kick start and find TDC again.. I think it MIGHT be my decompression lever? or possible the spark plug. it might just be my technique. I will check the intakes today although I doubt they have moved. SS intakes with less than 2 hours on them?

also, I dont know if this is normal as I cant remember since its been so long since ive ridden.. but the engine sounds quite loud, like a ticking sound when its idiling. I think im just being paranoid, pretty sure nothing wrong as it ran fine all day, but just wondeirng what you guys think. could it be the SS intakes making more noise?

thanks.

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What year 450? Have you ever pulled out the cam chain tensioner out and inspected? If it is not keeping proper tension on the chain it can make lots of noise. They do go bad, and when they stick, you can loose your whole motor.

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Thumper, I had very similar problems with my 06. My bike would so hard to kick at TDC that it bounced my leg back up like it was locked up. I finally checked the decompression lever and found it was way out of tolerance at .025 and should of been .011. I adjusted it and the bike is much easier to kick and quicker to start.

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Thumper, I had very similar problems with my 06. My bike would so hard to kick at TDC that it bounced my leg back up like it was locked up. I finally checked the decompression lever and found it was way out of tolerance at .025 and should of been .011. I adjusted it and the bike is much easier to kick and quicker to start.

ok, do you mean .011 MM or thousandhts of an inch? :thumbsup:

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