yz426f engine help


19 replies to this topic
  • bakeyz426f

Posted August 09, 2009 - 06:52 PM

#1

2002 yz426f broke a vavle and have the head off now and cylinder. they said the crank rod could be bent. do i need to replace the cyilinder check my pic of it and tell me what you think . where do i start and what parts should i get first. i got crank splitter, crank installer, piston puller, flywheel puller, clutch/flywheel holder, and valve compressor. do i need any other tools and where do i start on the bike. any help you can give me would be much apprecciated. i only got to ride her twice before she blew up. how do i check the crank rod?

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  • stevenacarter77

Posted August 09, 2009 - 08:09 PM

#2

i got crank splitter, crank installer, piston puller, flywheel puller, clutch/flywheel holder, and valve compressor. do i need any other tools

you got all them tools and you are asking us? do you know how to use the above tools? do you have a manual for that bike???

  • bakeyz426f

Posted August 09, 2009 - 08:13 PM

#3

not realy i just ordered them to do the repairs my self because my shop wanted 5000 bucks to rebuild my motor

  • stevenacarter77

Posted August 09, 2009 - 08:53 PM

#4

5grand thats crazy, you got a manual? read it i'll be back in about 8 hrs.

  • bakeyz426f

Posted August 10, 2009 - 03:48 AM

#5

yea i do

  • stevenacarter77

Posted August 10, 2009 - 03:59 AM

#6

did you do any reading on the valve ect?

  • bakeyz426f

Posted August 10, 2009 - 04:13 AM

#7

yea i did i think i will have to replace the head and all the valves

  • stevenacarter77

Posted August 10, 2009 - 04:34 AM

#8

maybe, have a machine shop look at it beside the one that wanted all your money don't go there again, also check on ebay/craigslist ect for a good used one, might be a whole lot cheeper. also check out the site i sent you for parts "service Honda" they also sell yammaha oem parts also i know they usually got the best price on the red parts. there is nothing here that you can't fix or get fixed as long as you study and use the manual so don't dispare there will be others on here that will chime in for moor help before its over.

  • stevenacarter77

Posted August 10, 2009 - 04:56 AM

#9

http://www.use-enco....PMITEM=628-3040 this is a Dial Indicator on the top right with a base you will need one if you want to check the crank to see if it is running true with out taking it out of the cases, to use it you will have to clamp on a piece of steel under the frame for the magnet bace to lock on to and it will need to have NO woble then with the side cases off you can put the dial up against the crank shaft and gently rotate it to see how much runout on the crank you manual has the specs on good/bad, also check the small end of the rod with wrist pin that holds the piston on it should be snug in the rod end not loose.

  • bakeyz426f

Posted August 10, 2009 - 02:20 PM

#10

do u think i should try this or should i just split the case.

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  • stevenacarter77

Posted August 10, 2009 - 02:23 PM

#11

well if it is not damaged you are only out about 40 if you check it but if you excange it and there was nothing wrong with it you are out 300+

  • bakeyz426f

Posted August 10, 2009 - 02:40 PM

#12

is it most likely bent because my valve hit and scared my piston preety good.

  • grayracer513

Posted August 10, 2009 - 03:14 PM

#13

That won't check the rod straightness.

Remove the crank and have it checked.

  • bakeyz426f

Posted August 10, 2009 - 03:16 PM

#14

is is neccessary to replace the camshaft assembly my shop had that on the parts list but all they did was take the head off and charge me three hundred bucks

  • grayracer513

Posted August 10, 2009 - 03:23 PM

#15

I can't see your cams. What's supposed to be the problem with them?

  • bakeyz426f

Posted August 10, 2009 - 03:31 PM

#16

the shop didnt tell me if there was a problem with them so i asume there fine. do they ussaly get damaged when a valve breaks.

  • grayracer513

Posted August 10, 2009 - 03:40 PM

#17

No, there has to be a reason to replace them. Ask them why. Ask them to show you.

  • ww44wrf450f

Posted August 11, 2009 - 06:45 AM

#18

@ $300 IMO, the shop price is high -- sounds like they c u commin --$5000 -- :thumbsup: IMO Bring The Bike Back HOME and never go back!!

Probably $300 would be the going price, but a good mechanic would have had the bike torn down in less than 1.5 hours?

Question, It sounds that you have tools, why didn't you do the work yourself? Did the bike come with the tool's, LOL?

  • grayracer513

Posted August 11, 2009 - 10:45 AM

#19

Probably $300 would be the going price, but a good mechanic would have had the bike torn down in less than 1.5 hours?

The ability to do the job in less time than the flat rate is how a good mechanic makes his money. They are only paid a fraction of the shop labor rate, and the quicker they can do the job, the quicker they can start the next one. Of course, it also behooves them to do it right the first time, since they are paid nothing to do it the second.

  • bakeyz426f

Posted August 11, 2009 - 12:55 PM

#20

i havent got the tools yet i ordered them last week





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