Newb doing the top end myself, PLEASE HELP! Lots of pics!


55 replies to this topic
  • Aka.Goose

Posted May 11, 2009 - 11:26 AM

#1

OK...I've got it ready to open up...
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I just purchased a flywheel puller and feeler gauges off ebay, so I'm going to wait a few days until those arrive (plenty of time to throw in some step by step advice, or hint and tips)...I already have the circlip tool, torque wrenches, etc...Let me know if there's anything else specific you can think of besides standard tools that I'll need...I think I can borrow a piston pin puller...
Recommendations as to what piston kit I should get, and whether to throw in hot cams (don't need speed just want this thing to be ultra reliable), a new cam chain or not since this one only has a few hours on it, new valves, seals, whatever...Any advice is like gold to me...
Like I said I'm clueless about this, but I've been told I'd be a fool not to do it myself...I'm totally just going by the service manual, and haven't done this before, so any and all help you can give is greatly appreciated...
I'm actually quite worried now that I've looked into the exhaust port...Looks like I might be in for more than I bargained for...There is a thick layer of black caked and baked on crud...
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  • grayracer513

Posted May 11, 2009 - 12:18 PM

#2

The highest level of reliability is going to come from using OEM parts. Go back with a stock piston, etc.

As far as cams go, if you aren't looking for more power, there is no reason to change them. If you'd like to change the power of your '07 a little, and perk up the low end without giving up much at all on top, put it back together with the stock intake, and an exhaust cam for an '06.

The "coke" in the exhaust port is what I'd expect to see in an engine that burns that much oil.

  • TIG88

Posted May 11, 2009 - 12:24 PM

#3

Just post if you run into trouble. Its not difficult in the least.

One thing to remember:

Dont torque things all at one. Do it in 2 or 3 increments. Lets take the cam caps for example. The manual recomends 82 in/lbs I believe, and Gray recomends 75. I went with 75. First torque all to 25, then all to 50, then all to 75. I did the same with my head bolts. You get the idea.

  • grayracer513

Posted May 11, 2009 - 12:36 PM

#4

One thing to remember:

Dont torque things all at one. Do it in 2 or 3 increments. ... I did the same with my head bolts. You get the idea.

The head bolts are a different process. See the manual, and ask if you don't understand it.

  • TIG88

Posted May 11, 2009 - 12:42 PM

#5

The head bolts are a different process. See the manual, and ask if you don't understand it.


Your right Gray. Now that you've said something and I've proved that I am indeed retarded, I remember. I was thinking about my old bike.

  • grayracer513

Posted May 11, 2009 - 01:12 PM

#6

Your right Gray. Now that you've said something and I've proved that I am indeed retarded, I remember. I was thinking about my old bike.

You're still correct that it's a good practice to run up in stages, and in the first step on the head bolts, where they are run to 22 ft/lbs, doing that in a couple of steps is a good. The second step, where they have been backed off, and are retorqued to 14 ft/lb is less critical because the load is lower, but it still doesn't hurt.

  • husqy360

Posted May 11, 2009 - 02:45 PM

#7

i got a complate top end kit, except gaskets for 105, from honda east side toledo. oem



good luck!! :excuseme:

and please post pics

  • Aka.Goose

Posted May 14, 2009 - 04:53 AM

#8

OK. So I opened it up last night...Timing was fine, cam tensioner was fine, valve clearances seemed to be around .13, magneto and flywheel look fine to me, piston and valves show signs of strikes...
Here's some pics:
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  • grayracer513

Posted May 14, 2009 - 06:46 AM

#9

So there's the noise you've been hearing. The piston skirt is bent/distorted/broken and allowing the crown to rock so far as to contact the valves on the intake side and the head on the exhaust side. You'll find that the oil ring groove is deformed or otherwise damaged enough that the ring can't control oil anymore.

  • WILLIAMS37

Posted May 14, 2009 - 06:54 AM

#10

i got a complate top end kit, except gaskets for 105, from honda east side toledo. oem



good luck!! :doh:

and please post pics


Small world, that dealership is 5 mins from my house.

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  • CaptainKnobby

Posted May 14, 2009 - 07:02 AM

#11

So there's the noise you've been hearing. The piston skirt is bent/distorted/broken and allowing the crown to rock so far as to contact the valves on the intake side and the head on the exhaust side. You'll find that the oil ring groove is deformed or otherwise damaged enough that the ring can't control oil anymore.


I dont see how you can see all that:excuseme:

  • grayracer513

Posted May 14, 2009 - 08:40 AM

#12

I dont see how you can see all that:excuseme:

The contact marks are on the piston for anyone to see. A deformed skirt is the only possible cause.

  • Wiz636

Posted May 14, 2009 - 10:00 AM

#13

I dont see how you can see all that:excuseme:


CSI YZ450 Forum

  • Aka.Goose

Posted May 14, 2009 - 10:02 AM

#14

GRAY, headed to the shop to order parts...
Can you help me with a parts list?
Do I need to replace the valves since they were taking the piston slap abuse?

And happy, belated by what, one day, birthday, by the way...
See, us 30 somethings show our age for all to see...

  • grayracer513

Posted May 14, 2009 - 10:19 AM

#15

It would definitely be safest to replace the 3 intake valves in case any were cracked by impacting the piston. The center and left outer don't look like they hit too hard, but you would still be taking something of a chance in reusing them. At least the right outer should go.

You need the cylinder off before you can decide whether it needs replacement, and the rod bearing needs to be checked. If it is loose, it could account for some of the reason the piston hits the head. Let's get that up and have a look before you get ahead of yourself on the parts list

Unless you have a really good discount relationship going with "the shop", you'll do much better at TT OEM than the dealer.

  • TIG88

Posted May 14, 2009 - 11:33 AM

#16

Would a factory defect typically account for this much damage? I guess it would have to, right?

Do you think it would be wise to check the crank for slop since its already this far apart? Or are crank bearings tougher than that?

  • grayracer513

Posted May 14, 2009 - 01:06 PM

#17

Would a factory defect typically account for this much damage? I guess it would have to, right?

Do you think it would be wise to check the crank for slop since its already this far apart? Or are crank bearings tougher than that?

Yes, I mentioned checking the crank already.

There are a number of manufacturing errors that could be involved here.
  • Piston incorrectly ground, or too tall, or fit improperly
  • Cylinder machined too short, or bore finished oversized (loose piston fit)
  • Rod bearing loose, or excessive early wear
  • Crankcase cylinder base cut too low
Out of all of these, only the piston seems the least likely to have actually been the culprit, but further investigation should show something.

  • husqy360

Posted May 14, 2009 - 02:30 PM

#18

OK. So I opened it up last night...Timing was fine, cam tensioner was fine, valve clearances seemed to be around .13, magneto and flywheel look fine to me, piston and valves show signs of strikes...
Here's some pics:
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thanks for the pics. :doh:
i did my cam chain this winter, but never did a top end.(next winter).

  • husqy360

Posted May 14, 2009 - 02:33 PM

#19

Small world, that dealership is 5 mins from my house.



go get some cheap riding gear then, deal of the week :doh:

jerseys 4 bucks
pants 13 bucks
gloves 1.99

its on till friday.

  • husqy360

Posted May 14, 2009 - 02:37 PM

#20

double post.





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