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Kickstart stuck after valve adjustment.

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2007 CRF450R Stock

I did the valve adjustment per the Honda Service Manual. Clearance is now at .178 on both which is within tolerance.

After reassembling the kickstart will cycle once or twice and then lock up.

I checked Cam timing and punchmarks...they all line up at TDC. The index line on the cam sprocket is as close as I can get it to the mark on the camshaft holder.

I checked clearances again and they are at .178. Not sure what is causing the problem. Any suggestions?

Thanks.

____________________
2007 CRF450R Stock
2016 CRF110

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So I found a few similar issues on here.  I removed the plug and the engine rotates fine now.  Checked TDC with pencil in the whole and it's right on.

So the piston is hitting the plug at TDC all of a sudden after a valve adjustment?  What am I missing?

Thanks.

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Im having the same problem with my rmz 450 and i had a guy tell me that my cam chain could be streched (witch it was) and it was binding on bottom end i got a new chain and it never fixed the problem. If i take my spark plug out it doesnt have a hard spot at tdc. 

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Reinstalled the plug and checked clearances again.  I don't know why but now they are way off...about .229mm both sides.  This might explain the problem as with the plug removed, air can escape easy.  With it inserted, and the gap so out of tolerance, the valves aren't opening enough.  I think.

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If I'm not mistaken clearances for this bike is 0.13mm + -. 03 intake
.0.16mm +-3 exhaust
Is your auto decompression working?

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1 hour ago, DinoY said:

If I'm not mistaken clearances for this bike is 0.13mm + -. 03 intake
.0.16mm +-3 exhaust
Is your auto decompression working?

It's .16mm +-.03mm intake.  Yes, auto decompression is working.

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Did you use a different bolt on the magneto?
You said after you removed the plug engine turned freely
Is it squizing somewhere on the plug?

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You guys need to take time and know what your doin.  Learn how to do things correctly!!

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13 hours ago, DinoY said:

Did you use a different bolt on the magneto?
You said after you removed the plug engine turned freely
Is it squizing somewhere on the plug?

Nothing is different from when I disassembled it.  I tested again with the plug out and it does kick freely.

I checked timing marks and and they are dead on.

@yz250f 78 Not sure what that means.  I'm using the 2007 Honda CRF45R Service Manual and following step by step.

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Two things can happen. Ive seen both. Oddly last summer, I found the spring item 7 with the little 90 degree elbow broken off on 3 bikes and a quad, in a row. Very strange, but...

 

That spring, or the pin item no. 29 can also snap off. Honda actually did a recall one year on that part. I dont remember the year.

If the cam timing is correct, there is probably where your issue lies.

When the spring is broken, it allows the weight to extend and retract the pin, which is what bumps the rocker arm and decompresses the cylinder so you can kick it. If the weight extends, on the slightest motion, or even just gravity and it will, it wont decompress the cylinder at all. If the pin is broken off, same scenario, different reason. MjAzMzQ2MA-65d958c7.png

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10 minutes ago, Shawn_Mc said:

Two things can happen. Ive seen both. Oddly last summer, I found the spring item 7 with the little 90 degree elbow broken off on 3 bikes and a quad, in a row. Very strange, but...

That spring, or the pin item no. 29 can also snap off. Honda actually did a recall one year on that part. I dont remember the year.

If the cam timing is correct, there is probably where your issue lies.

When the spring is broken, it allows the weight to extend and retract the pin, which is what bumps the rocker arm and decompresses the cylinder so you can kick it. If the weight extends, on the slightest motion, or even just gravity and it will, it wont decompress the cylinder at all. If the pin is broken off, same scenario, different reason. 

The spring is still there and hooked up correctly to the weight.  Also, the pin is good and working correctly.  If I manually push the weight "out", the pin moves inside the camshaft.

 

 

IMG_2160.JPG

IMG_2161.JPG

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No, it's not assembled correctly. The weight is all the way out. It should be in, resting on the center pin when it's not running. As it sits in that picture, the pin is in, not protruding from the cam lobe. It's like the spring is wound the wrong way or something.

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18 minutes ago, Shawn_Mc said:

No, it's not assembled correctly. The weight is all the way out. It should be in, resting on the center pin when it's not running. As it sits in that picture, the pin is in, not protruding from the cam lobe. It's like the spring is wound the wrong way or something.

Hmm...I am going by the instructions/images in the service manual...maybe the spring is no longer working?

 

Untitled.jpg

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I pulled the spring off and this is what I have....

Looks right to me.  Where does the other end (not 90degree bend) go?

 

IMG_2163.JPG

IMG_2164.JPG

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That double 90 bend end, goes around the weight and pushes it towards the middle. Notice in the pictures, where your weight is, and then notice in the manual picture where the weight is.

It's kind of hard to tell, but I think you got the spring on there upside down.

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1 hour ago, Shawn_Mc said:

That double 90 bend end, goes around the weight and pushes it towards the middle. Notice in the pictures, where your weight is, and then notice in the manual picture where the weight is.

It's kind of hard to tell, but I think you got the spring on there upside down.

Yea, that's how it was.  I took it off and tightened it up a little.  I also found this thread and the 2nd picture shows the other end actually wrapping around one of the holes in the sprocket.  

Regardless, the spring is now pushing the weight to the inside and the kickstart is still doing the same thing.

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So, youre saying that when you move the weight back and forth, the pin extends and retracts the way it should, correct? Now, if that spring is broken off (it's supposed to have two ends) it's probably not imposing enough load to prevent the weight from extending way prematurely. That spring should hold that weight to the inside of the gear to at least 800 rpm. The cam spins half speed, so 400 rpm on the cam itself. When you kick the bike over, you generally get about 350 rpm out of them. On the first fire, the engine speed is instantly enough to extend the weight. Yours is still extending during the kick. Buy a new spring. And triple verify that when that weight extends, the pin retracts. It's not impossible to assemble the pin and rod incorrectly and it wont retract.

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19 hours ago, Shawn_Mc said:

So, youre saying that when you move the weight back and forth, the pin extends and retracts the way it should, correct? Now, if that spring is broken off (it's supposed to have two ends) it's probably not imposing enough load to prevent the weight from extending way prematurely. That spring should hold that weight to the inside of the gear to at least 800 rpm. The cam spins half speed, so 400 rpm on the cam itself. When you kick the bike over, you generally get about 350 rpm out of them. On the first fire, the engine speed is instantly enough to extend the weight. Yours is still extending during the kick. Buy a new spring. And triple verify that when that weight extends, the pin retracts. It's not impossible to assemble the pin and rod incorrectly and it wont retract.

Okay, thanks.  Are these springs readily available?  I noticed none of the usual online suppliers have them any longer.

Edited by TJPB

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6 hours ago, TJPB said:

Okay, thanks.  Are these springs readily available?  I noticed none of the usual online suppliers has them any longer.

Apparently not. According to this dealerships parts catalog Honda no longer makes that part.

http://shop.hbhonda.com/fiche_section_detail.asp?section=418603&category=Motorcycles&make=Honda&year=2007&fveh=12893

https://www.partzilla.com/catalog/honda/motorcycle/2007/crf450r-a/camshaft-valve

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2 hours ago, mrmoto35 said:

The 2006 version of the part looks exactly the same so I'm going to try it.  It's probably got different calibration though I bet.

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