Almost done w/ my first rebuild


29 replies to this topic
  • Goosedog

Posted November 01, 2006 - 05:10 AM

#1

Thought I'd post an update to inspire other mechanic wanna-be's like myself. My inspiration came from a friend of mine that's a mechanic and lots of tech support from you guys here at TT.

So far I've torn down my 426 and now building it back up putting in new piston, rings, gaskets, valves and seals. While I was at it I upgraded to the '03 450 auto de-comp exhaust cam. Refurbished the carb as well with all new o-rings, vent lines and upgraded the AC pump cover with a Quickshot.

Now that it's 90% back together I have to bring it back to the dealer for a valve adjust and then the finale re-assembly here at my garage.

I've done 3/4 of the work myself and am grateful for the couching I got from my mechanic buddy. Not only has it been very satisfying to try something so daunting but now I can really appreciate how everything works in the bike.

Damn...I can't wait to ride this thing, it's gonna scream.:mad:

  • grayracer513

Posted November 01, 2006 - 08:59 AM

#2

I have to bring it back to the dealer for a valve adjust

¿Why?

  • Goosedog

Posted November 01, 2006 - 10:53 AM

#3

¿Why?


I don't have the experience or the shims to do it here at my house. The mechanic that's been couching me is from the dealer and he says bring it down and he'll do it there. That's also where I had the cylinder honed and the valves put in the head.

  • grayracer513

Posted November 01, 2006 - 11:42 AM

#4

If you have already assembled your camshafts, and you own a set of feeler gauges, you have the experience you need. Measure them, find any that are out of spec, and remove the shims that are currently in place. Read the number marked on them, do some simple math, and go get the right shims to make the correction. None of that is anything you haven't already done, is it?

At the verry least, have the tech show you how as he does it.

  • TexN343

Posted November 01, 2006 - 11:29 PM

#5

Lol Sounds like you did the grunt end of the work for him. Why waste money now? Unless he's doing it for parts cost I wouldn't waste time loading it up and hauling it up there. I wouldn't waste the money on those shim kits you can buy cuz you won't ever use even half the sizes.

  • new2blu

Posted November 02, 2006 - 06:40 PM

#6

Thought I'd post an update to inspire other mechanic wanna-be's like myself. My inspiration came from a friend of mine that's a mechanic and lots of tech support from you guys here at TT.

So far I've torn down my 426 and now building it back up putting in new piston, rings, gaskets, valves and seals. While I was at it I upgraded to the '03 450 auto de-comp exhaust cam. Refurbished the carb as well with all new o-rings, vent lines and upgraded the AC pump cover with a Quickshot.

Now that it's 90% back together I have to bring it back to the dealer for a valve adjust and then the finale re-assembly here at my garage.

I've done 3/4 of the work myself and am grateful for the couching I got from my mechanic buddy. Not only has it been very satisfying to try something so daunting but now I can really appreciate how everything works in the bike.

Damn...I can't wait to ride this thing, it's gonna scream.:mad:


Glad to see you weren't to afraid to do the work yourself. You will now be able to do a rebuild next time with little to no help at all!

  • MXKyle

Posted November 03, 2006 - 04:40 AM

#7

The cam chain for your yammi is only about $30. You should change that too while you are rebuilding.

--KT--

  • StreetbikePimp

Posted November 03, 2006 - 09:19 AM

#8

Don't even waste your money on buying shims. Get a diamond honing file and a dial caliper and file down your stock shims to the size that they need to be.

  • grayracer513

Posted November 03, 2006 - 09:46 AM

#9

A, that's a time consuming pain in the butt and requires a micrometer, and B, there's no way you can hand file a shim with both sides dead parallel and truly flat.

I know some insist that they've done this, and that it works fine, and that's just great, but IMO, it's just a lot easier to pop down to the dealer and pick up the ones you need, and be done.

If your Yamaha guy doesn't have them, and they may not, go to a Honda shop. Most Honda places will have a stack of them in most sizes. Use the shims for a CRF450 or the CRF250 (exhaust valves). There are principally only two shim sizes used in most Japanese four strokes with this type of lash adjustment, 9.48mm diameter, and 7.48mm. The YZ4**F uses the 9.48mm size, and Honda shims are just the same.

  • yogist

Posted November 03, 2006 - 03:51 PM

#10

Don't even waste your money on buying shims. Get a diamond honing file and a dial caliper and file down your stock shims to the size that they need to be.



I lay mine on a granite plate and sand with some emery......check with mics..I can get those valves in dead nuts..

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • yogist

Posted November 03, 2006 - 03:52 PM

#11

The cam chain for your yammi is only about $30. You should change that too while you are rebuilding.

--KT--



my 01 cam chain was 56.00..........

  • Goosedog

Posted November 07, 2006 - 06:03 PM

#12

Got 'er back together today and she started on the first (didn't have to find TDC) kick! Idled great for two minutes, quit and wouldn't restart.

After a mild panic attack and ten minutes trying to figure out what I'd done wrong,

I realized the bike was out of gas.:mad: :mad:

  • Badkaw2

Posted November 07, 2006 - 06:16 PM

#13

Out of gas! Now that's funny. Sounds like something I would do. :mad:

  • YzGuy79

Posted November 07, 2006 - 09:10 PM

#14

Got 'er back together today and she started on the first (didn't have to find TDC) kick! Idled great for two minutes, quit and wouldn't restart.

After a mild panic attack and ten minutes trying to figure out what I'd done wrong,

I realized the bike was out of gas.:mad: :mad:


Been there..Done that!

Glad to hear that's all it was:thumbsup:

  • YZ426F Rider

Posted November 08, 2006 - 11:53 AM

#15

Out of gas! Now that's funny. Sounds like something I would do. :cheers:

No kidding...except that I would have torn the carburator apart before checking the tank!

  • Supafreak_711

Posted November 08, 2006 - 02:27 PM

#16

Common man, you have gone this far! You can set the valves by yourself. I was intimidated my first time, but got it done with the help of the guys on TT (if I remember right, grayracer answered alot of my questions)

  • ausgeflippt13

Posted November 08, 2006 - 03:57 PM

#17

For future reference, you'll prob wanna invest into a clymer guide or something of the like. It's a great help in all sorts of applications for your bike. I believe the cheaper ones are around $30 and the full-on mechanic's books go for only about $60.

Anyway, great job and welcome to the club. Only problem is that once you start you'll never wanna stop so you'll end up trying to rebuild anything and everything that's rebuildable :cheers:

...and do the valve adjust on your own...

  • Florida_426

Posted November 08, 2006 - 05:58 PM

#18

If you don't already have a shop manual as suggested get a Yamaha manual from one of the on line .pdf file locations, like Motoman393 site. The Clymer and Haynes have errors in them. My factory manual is pretty worn and oil stained but is my best friend in the shop.

Bill

  • GONE1445

Posted November 08, 2006 - 08:30 PM

#19

ok so give us a list of what you replaced/had done/or did your self

and the cost if you dont mind

I may do this this winter to my good ol 426

  • Butta

Posted November 08, 2006 - 08:47 PM

#20

my 01 cam chain was 56.00..........



My '05 was $13......

:cheers:





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