wr426 kick starter wont move, but can turn from crank


44 replies to this topic
  • MANIAC998

Posted May 13, 2011 - 02:41 AM

#21

I agree with Birdy426. That looks like the plunger for the neutral switch. Maniac

  • tribalbc

Posted May 13, 2011 - 06:21 AM

#22

The crank does look a bit suspicious...though that IS where they are blue from the factory. It's just usually more uniform. It's from locally heating the crank halves to enlarge the pin holes. That makes it easier to put the crank together.

Looking at that pin, it actually looks like the plunger that goes in the shifter drum for the neutral switch. The mushroom head on the right side looks to consistant to be displacement type damage...


If my memory serves me correct both halves of the crank have the discoloration and it isn't so localized looking. That really looks like heat generated from a bad bearing.
At this point the only true answers come from splitting the cases and going through everything.

  • highcam

Posted May 19, 2011 - 07:17 AM

#23

so been at a hold up for the past couple days... made my puller tool and the bolt on the end of the crankshaft that you press against to remove the CDI Magneto rotor mushroomed out and the rotor did not budge. :smirk:

So i ground the bolt down with a dremel and I may try using some heat this time?? Suggestions?

  • byggd

Posted May 19, 2011 - 12:06 PM

#24

Not to be a smartazz but why didn't you just buy the correct tool??

Edited by byggd, May 19, 2011 - 03:44 PM.


  • bg10459

Posted May 19, 2011 - 01:52 PM

#25

... made my puller tool and the bolt on the end of the crankshaft that you press against to remove the CDI Magneto rotor mushroomed out and the rotor did not budge. :smirk:

Don't feel bad. I bought a Motion Pro flywheel puller and still mushroomed the end of the crank and ripped the threads out of the flywheel :smirk: I cut the flywheel off and got 3/4 of the way through the hub before it finally popped off of what was left of the shaft.
You can try the puller again with heat and an impact gun, or try to tighten the puller, heat and then tap, tap, tap, tighten, tap, tap, tap, etc. (the method I used to no avail). If that doesn't work, you might as well break out the grinder and buy a new flywheel.

  • 1rad58

Posted May 19, 2011 - 02:16 PM

#26

sounded like a kick start or idler gear at first although if it was the idler you would feel it all the time. what i would do is put the bike up on a stand and put it in gear and crank the engine over with the socket and do this going through all the gears and see if you feel som resistance in any or all gears and go from there. if you do then its a tranny problem but just my suggestion is to fully tear the motor down and clean all the metal shavings out.. or if you want to do it the cheaper faster way, although i wouldnt recomend unless you are completely against tearing the motor down, then you could put half to a full quart of old, metal free, motor oil in and try to work it around and drain some shavings out then fill the motor, to dealer specs, with used motor oil again and if you think you have most the shavings out then run it very breifly, maybe 15 seconds, and then drain it and do it again untill satisfied. then fill er up with fresh oil and go for a short ride then change the oil again, letting it drain reallllyyyyy goood. then fill her up with the oil of your choice and she should be good to go as long as you got the problem figured out and fixed

  • tribalbc

Posted May 19, 2011 - 05:38 PM

#27

You can try the puller again with heat and an impact gun, .


This my prefered method, heat and an impact.

  • shelbyguy

Posted May 20, 2011 - 06:21 AM

#28

If my memory serves me correct both halves of the crank have the discoloration and it isn't so localized looking. That really looks like heat generated from a bad bearing.
At this point the only true answers come from splitting the cases and going through everything.


My crank that came out of my 426 looked identical. But the rod was trashed.
As birdy said little bearing looking thinger is for neautal safety switch

Take a few mins and measure horizontal and axial play in the rod, you don't NEED to pull it apart.

Use your puller and don't be so agressive with it.
Tighten it up, heat, rap it with a hammer shouldn't be a problem. Have removed hundreds of Vtwin, and I4's with this method.

  • highcam

Posted May 21, 2011 - 09:05 AM

#29

im gonna try with some heat, hopefully today.

As far as the crankshaft, im not so worried about the color as the fact that although i haven't measured it there is definitely a good amount of play in between the crank and the rod.

I will also try given it some taps to see if that makes it budge....

Thanks for the advice guys.

  • highcam

Posted May 21, 2011 - 10:36 PM

#30

So got it off... used a torch and pb blaster as well.. put the tool on put a small amount of tension, and tapped with a mallet :smirk: came of no problem.

thanks for the help I can't believe how easy that was in comparison to my initial attempt.

So hopefully tomorrow i will finish splitting the cases and start going through the hole thing.

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  • highcam

Posted May 22, 2011 - 07:55 PM

#31

so cases split everything is apart.

I think I may just replace the crankshaft as an assembly...being that the rod bearing is shot, and one side of the crank is no good now from the bolt mushrooming.... best choice seems to be to replace it, I think.

The rest of the bearings in that are pressed into the case(s) seem to move freely and have very minimal play in them.

There is a lot of metal shavings however in the case so I am glad to have it open so I can clean all of that out.

Since the timing chain needs to be replaced, yamaha recommends replacing the cam gears as well... Hot cams??? (why not just do it all)
As well why do they not recommend replacing the gear for the timing chain on the crankshaft as well then??

Well anyways it is time to compile a list of all parts that need to be replaced and purchased....

Any recommendations as far as rebuild and parts to use... So far I am thinking that I will go with lukes racing 444 big bore kit as I need a new piston and cylinder.

As far as the cam chain being replaced I am thinking about getting hot cams intake and exhaust cams as well which will have the benefit of the auto-decompression.

Now as far as the cylinder head goes... this is a 2001 so I have the titanium valves. I figure well I have the whole thing apart I might as well do something here...
IF no valves are bent (they shouldn't be) would it be sufficient or even needed to go ahead and replace the valve springs and have the valve seats re-ground? I really don't want to have to replace the valves ($70/ea) as there is another $350 dollars and this is already getting expensive...

Suggestions???

  • tribalbc

Posted May 22, 2011 - 08:26 PM

#32

so cases split everything is apart.

I think I may just replace the crankshaft as an assembly...being that the rod bearing is shot, and one side of the crank is no good now from the bolt mushrooming.... best choice seems to be to replace it, I think. OEM is best bet if they are cheap like the 450- $225

The rest of the bearings in that are pressed into the case(s) seem to move freely and have very minimal play in them. With lots of shavings in the case at a minimum I would replace the main bearings, but really you should do your counterbalancer and tranny bearings as well, especially with high miles

There is a lot of metal shavings however in the case so I am glad to have it open so I can clean all of that out.

Since the timing chain needs to be replaced, yamaha recommends replacing the cam gears as well... Hot cams??? (why not just do it all)
As well why do they not recommend replacing the gear for the timing chain on the crankshaft as well then?? No one really does this, if the cams and cam gears are in fine shape no worries, just replace the chain. You can get auto decomp just changing the exhaust cam. New crank gear comes with the new crank, they are an integral unit.

Well anyways it is time to compile a list of all parts that need to be replaced and purchased....

Any recommendations as far as rebuild and parts to use... So far I am thinking that I will go with lukes racing 444 big bore kit as I need a new piston and cylinder.

As far as the cam chain being replaced I am thinking about getting hot cams intake and exhaust cams as well which will have the benefit of the auto-decompression.

Now as far as the cylinder head goes... this is a 2001 so I have the titanium valves. I figure well I have the whole thing apart I might as well do something here...
IF no valves are bent (they shouldn't be) would it be sufficient or even needed to go ahead and replace the valve springs and have the valve seats re-ground? I really don't want to have to replace the valves ($70/ea) as there is another $350 dollars and this is already getting expensive...
How many times have your valves been shimmed? If 2 or less times you would probably be fine with springs and seals. Do a liquid leak test on your valves
Suggestions???


See bold above

  • highcam

Posted May 22, 2011 - 10:03 PM

#33

so looks like the crankshaft assembly for the wr426 is around $420.... Makes me wonder if its worth it to by a used one of ebay and take it apart and replace the rod bearings... may end up being more trouble than its worth thought i guess....

I am gonna call this week though and see if one of the dealerships will work with me if I order everything from them.

  • bg10459

Posted May 23, 2011 - 04:12 AM

#34

Tribal has good advice there :smirk:
I went with a Hotrods crank. I looked, and I couldn't find an OEM crank even close. I would have preferred one, but just couldn't justify the difference.
If you are doing the crank, as mentioned above, I would do the main bearings, as well. If any bearings have even minimal play, I would replace them.
Zanotti is hard to beat for OEM parts, but make sure you get everything into one order.

  • highcam

Posted May 23, 2011 - 09:55 AM

#35

Alright.... So I just went through everything.

I poured some acetone in the head through the intake and exhaust ports... no leakage.

What is the stock shim size? I figure I can measure the shims to see how far the valves are adjusted from stock as there is no way I can know how many valve adjustments have been made.

It does however look like I may need a lot of stuff... I am not sure about a couple things so I will take nice pictures (got the good camera) and see your guys opinions.

Depending on the outcome of the pictures... it may simply just not be worth the amount of time and money to get this engine working correctly.

Looks like I probably need a new oil pump as well, as it does not spin as smoothly as I think it should.

So far I need:
all the gaskets and circlips
crankshaft assembly
valve springs
valve seals
timing chain
impeller shaft (??) and bearing as well as new seals
oil pump & second rotor set
piston & cylinder
main bearings as well as transmission bearings
balance shaft (maybe)
:smirk:


Pics of the balance shaft and water pump shaft.

Posted Image

Posted Image

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Some metal shavings in the case after I already wiped some of them out.

Posted Image

Edited by highcam, May 23, 2011 - 11:13 AM.


  • highcam

Posted May 23, 2011 - 08:03 PM

#36

found the crankshaft for $320 or $340 can't remember.

Hows the balance shaft look though? It seems to have pitting on it but I did not notice any damage to the case.. I will look again and double check though. But does that need to be replaced? Its another $200, meh

  • miweber929

Posted May 24, 2011 - 04:36 AM

#37

There is no "stock" shim size, every single engine is different. If it's of unknown history, take the head to a known shop and have them inspect it.

Rebuilding a damaged motor can be a never ending money pit that will only be as good as it's weakest part when done. If you talk to some people they say "replace everything, now that you got it apart" and yet others say "replace the bare minimum". Somewhere in the middle is where you want to be or you'll stick $1500 into a bike worth $1300, something I have done in the past.

Just be aware what you don't replace may cause issues in the future: don't replace the valves, they may need attention in a period of time.

To me, your balancer shaft looks normal, almost like casting marks but I've never had tge WR motor apart to know for sure. The shaft you've shown is shot, however.

Replace what's broken or worn, skip what's not and you should come out just fine in the end without throwing too much $$$$ at this.

Mike

  • highcam

Posted May 24, 2011 - 01:18 PM

#38

There is no "stock" shim size, every single engine is different. If it's of unknown history, take the head to a known shop and have them inspect it.

Rebuilding a damaged motor can be a never ending money pit that will only be as good as it's weakest part when done. If you talk to some people they say "replace everything, now that you got it apart" and yet others say "replace the bare minimum". Somewhere in the middle is where you want to be or you'll stick $1500 into a bike worth $1300, something I have done in the past.

Just be aware what you don't replace may cause issues in the future: don't replace the valves, they may need attention in a period of time.

To me, your balancer shaft looks normal, almost like casting marks but I've never had tge WR motor apart to know for sure. The shaft you've shown is shot, however.

Replace what's broken or worn, skip what's not and you should come out just fine in the end without throwing too much $$$$ at this.

Mike



Thanks man.

I was thinking casting marks as well for the most bot the ones on the curved surface look weird to me... it looks like maching lines and then some type of pitting, however there is no damage on the case so it does seem a possibility to be casting marks.
If someone who has had there wr/yz apart could chime in I would appreciate it.
I will replace the water pump impeller shaft. So far I am kind of in the situation of spending $1500 on a $2500 bike, but when u factor in the exhaust i recently bought etc.... its turning into more than its worth.

If the head looks good (I'm taking it up to a guy I had do head work previously) then I will fix the motor. I figure i'd rather spend some money and know for sure everything is fresh and new than spend some money for something I can't be sure on.

  • highcam

Posted June 07, 2011 - 03:13 PM

#39

Everything is ordered.

Ended up needing to replace the exhaust valves as they were barely in spec, but the intake valves are fine.

Went with Lukes racing 444 12.5:1
new tranny bearings, main bearings, balancer bearings.
new oil pump impeller shaft etc.

Only decision left is what I want to do with the cams.

Has anyone used hotcams? If so, quality product?

The other option would be to get the yz450 exhaust cam.... Price difference is not a a lot ~$60 so im open to suggestions.

  • GCannon

Posted June 07, 2011 - 03:59 PM

#40

I have the hot cam exhaust cam it is the one of the very best mods i have done. the auto decomp is fantastic. I have even kept the decomp lever for cylinder clearing after a tipover and when the motor stalls at TDC . My wife can now start my bike which could never have happened before the auto decomp cam.


with the big bore kit i would do a valve grind and port job especially if you install both intake and exhaust HotCams.

I just love sitting at my desk and spending other peoples money.:ride:




 
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