06 YZ450 rebuild questions


13 replies to this topic
  • Colnta

Posted February 27, 2011 - 09:37 AM

#1

A buddy brought me his old bike as he got it back from a local dealer.. in a box. They split the case, took everything apart and told him they wanted $6k to put it back together. He bought a 09 and tossed the 06 in the garage.

I figured it would be a good winter project to put it back together, so after hours of cleaning parts I'm almost ready. I've dry fit the transmission, and got it shifting, but since I didn't take it apart, and they just tossed everything into a box I'm running into questions; question that I hope you folks can help me with.

1) Does anybody know what bolts (16*) hold the shift guide? The guide is the part that holds the segment against the shift cam. When I dry fit it I used two chrome bolts (5/8" long, 10mm head) I found in the box.

* referring to the TT store OEM schematic to help make myself clear.

2) I believe I put the transmission together correctly (they gave it back with a gear on the drive assembly backwards.. as far as I can tell). The transmission wouldn't turn freely (would bind at some point as it turned) before I put it together "correctly". Now it shifts properly using the shift lever, but is hard to shift by turning the cam with my fingers. The manual implies that it should shift cleanly by turning the cam, but I wasn't sure how cleanly? It feels partly like the forks bind a little (no oil on them after cleaning), and also dogs don't line up without help. I assume that when the cases are together the forks stay aligned better, and that operating the transmission was aligning the dogs - I'd prefer not to split the case after destroying the transmission due to an assumption.

3) Permatex anaerobic flange sealant ok when I put the case back together?

4) Anything else to consider in the transmission? So far it has been surprisingly simple, which makes me wonder if I'm missing something? I prefer to put things back together after I've taken them apart.. starting from a pile of parts is a shock to my normally anal attention to detail.

I was thinking about documenting the whole project with a bunch of pictures and notes about what I learn. If that would be interesting to anybody let me know, and I'll make more of an effort to actually finish something.

Thanks.

  • grayracer513

Posted February 27, 2011 - 10:34 AM

#2

  • The bolts sound like the right ones.
  • It will normally be somewhat difficult to shift with your fingers because of the way the whole setup works. Much easier to turn using the center bolt with a socket. It also requires the trans shafts to be rotated relative to one another to align the locking lugs with each other, as they will align or misalign randomly.
  • Yes, that should work.
  • It is simple, really. If you can shift through all 5 gears using the shift lever and spin the trans freely in each gear with the clutch off, you should be good. Remember that the shafts can drift without the clutch and front sprocket in place, and you might encounter some binding or knocking unless you pull the main shaft toward the clutch, and the output shaft toward the sprocket.


  • lumpy790

Posted February 27, 2011 - 05:14 PM

#3

Just to clarify.... What was wrong with it when he took it to the dealer? Has this problem been addressed?

  • Colnta

Posted February 27, 2011 - 10:29 PM

#4

Long story, but basically he took it in to have them look it over (valves etc.) and for some reason they decided to split the cases. They took absolutely everything apart except the oil pump. Then they wanted $6k to put it back together. The bike was running without known issues prior to that.

To be fair to the local shop, second gear and pinion should be replaced, the whole clutch needs to be replaced, and it needs a whole new top end (he had 200hrs on it with only valve adjustments). So given labor etc. their estimate was crazy, but perhaps not robbery... unless you compare it to $8k for a new 09, which is what he bought instead of fixing the 06.

This was a few years ago, and the motor has been sitting in the box they gave it back to him in since. I didn't have a project this winter so I decided get it running. Imagine taking your motor apart, tossing all of the parts into a box, shacking it up (you can put the valves in a bag.. but don't wash the motor first), and then putting it back together. What could be more fun? Honestly, it has been fun. I've never needed to split the case on any of my own bikes, so the chance to learn without risk has been worth any frustration.

Speaking of valves, does anybody know what the stock shim is? He paid to have them adjusted a couple of times, but when I checked, every one was a 170. I don't have a lot of experience, but was surprised that they would all be the shimmed the same after a couple of adjustments.

  • Mr. Neutron

Posted February 28, 2011 - 09:17 AM

#5

Long story, but basically he took it in to have them look it over (valves etc.) and for some reason they decided to split the cases. They took absolutely everything apart except the oil pump. Then they wanted $6k to put it back together. The bike was running without known issues prior to that.

To be fair to the local shop, second gear and pinion should be replaced, the whole clutch needs to be replaced, and it needs a whole new top end (he had 200hrs on it with only valve adjustments). So given labor etc. their estimate was crazy, but perhaps not robbery... unless you compare it to $8k for a new 09, which is what he bought instead of fixing the 06.

This was a few years ago, and the motor has been sitting in the box they gave it back to him in since. I didn't have a project this winter so I decided get it running. Imagine taking your motor apart, tossing all of the parts into a box, shacking it up (you can put the valves in a bag.. but don't wash the motor first), and then putting it back together. What could be more fun? Honestly, it has been fun. I've never needed to split the case on any of my own bikes, so the chance to learn without risk has been worth any frustration.

Speaking of valves, does anybody know what the stock shim is? He paid to have them adjusted a couple of times, but when I checked, every one was a 170. I don't have a lot of experience, but was surprised that they would all be the shimmed the same after a couple of adjustments.


Man, Colnta, there's a lot there that just doesn't seem to add up, to me. But the shop's price for working on the engine certainly added up! :busted: I almost wonder if buying a new motor wouldn't be less frustrating, and likely cheaper in the long run...... :thumbsup:

It seems REALLY odd that all the valve shims would be the same, for one thing. I just recently went through the shimming valve clearances deal, and none of my engine's valve shim pads were the same, from the factory. I learned (from Grayracer513, and doing a lot of "SEARCH"es....) that the Yamaha assemblers set the valve clearances up at the small end of the tolerance zone. What with all the tolerances in engine parts, it would really be remarkable, I would think, for all the valves to need the same shim pad..... :smirk:

Anyway, I guess your plan for the valves would be to assemble the valves & head, and then check the clearances with feeler gages. After you know what the clearances are, then you will need to calculate, and buy the correct shim pads. By any chance did that shop mark which valves go where, or which "buckets" (they're actually called lifters) belonged where? Those things do need to go back in the holes they came from, but folks have put them back before without that actually happening, and the motors will actually run....

Jimmie

  • lumpy790

Posted February 28, 2011 - 09:56 AM

#6

Sounds like the owner took his bike in and said give me an estimate for anything that might be wrong and they totally disasembled it to inspect. Would be interesting to see the repair order.

  • Colnta

Posted February 28, 2011 - 10:17 AM

#7

Sounds like the owner took his bike in and said give me an estimate for anything that might be wrong and they totally disasembled it to inspect. Would be interesting to see the repair order.


I believe that is exactly what took place. He couldn't find the part list they gave him, but said it was around three pages long. His hour meter was over the 200 hour mark, so it wasn't unreasonable to check everything out, and like I said before, second gear and pinion need to be replaced (badly), so it was good that we found that.

What is sad is that this is the second time this has happened to him. He used to ride a rm 250, but took it in and ended up with a bike he just took to the dump. I wish I'd known him then; I know I can make one of those run :thumbsup:.

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  • Colnta

Posted February 28, 2011 - 10:29 AM

#8

Man, Colnta, there's a lot there that just doesn't seem to add up, to me. But the shop's price for working on the engine certainly added up! :busted: I almost wonder if buying a new motor wouldn't be less frustrating, and likely cheaper in the long run...... :thumbsup:


He just went and bought a new 09, and has been happy. We had just met back then (we ride at the track together every night), and I noticed he was gone for a while and then came back with a new bike. I didn't know what had happened. He can afford it, and isn't really interested in the mechanical side, so while I'm sure he was annoyed, it just wasn't worth it to him to deal with it.

I'm only putting it back together now for something to do. I've only owned 2 strokes, and figured before I even consider buying a 4 stroke I'd make sure I can work on them. So far so good.

It seems REALLY odd that all the valve shims would be the same, for one thing. I just recently went through the shimming valve clearances deal, and none of my engine's valve shim pads were the same, from the factory. I learned (from Grayracer513, and doing a lot of "SEARCH"es....) that the Yamaha assemblers set the valve clearances up at the small end of the tolerance zone. What with all the tolerances in engine parts, it would really be remarkable, I would think, for all the valves to need the same shim pad..... :smirk:


That is what I was wondering. I don't know enough to be certain, but it seemed really odd to me that the wear would be linear across five valves.

Anyway, I guess your plan for the valves would be to assemble the valves & head, and then check the clearances with feeler gages. After you know what the clearances are, then you will need to calculate, and buy the correct shim pads. By any chance did that shop mark which valves go where, or which "buckets" (they're actually called lifters) belonged where? Those things do need to go back in the holes they came from, but folks have put them back before without that actually happening, and the motors will actually run....

Jimmie


I received the valves in a plastic zip-lock bag. I have no idea what goes where. That is partly why I checked the shims that I have.. just trying to guess what to put where. Since they are all the same, it make that part easy.

I'm a little worried about the buckets, but if this bike ever actually starts, it will be getting a new top end, so assuming running it for a few minutes with the buckets in the wrong slots won't destroy anything, I'm not too concerned. We just don't want to spend a lot of money up front if the thing doesn't even run.

  • lumpy790

Posted February 28, 2011 - 06:50 PM

#9

I just put a YZ450F basket case back together and all the Intake shims were the same and the exhaust shims were the same size too.

  • Mr. Neutron

Posted February 28, 2011 - 06:53 PM

#10

I just put a YZ450F basket case back together and all the Intake shims were the same and the exhaust shims were the same size too.


All 5 of them the same size? From the factory, or from the previous owner, or another mechanic?

What sort of clearances did they yield?

Edited by Diesel Goober, February 28, 2011 - 07:17 PM.
had a question....


  • brentn

Posted February 28, 2011 - 07:08 PM

#11

Are brand new heads from the factory, or from a company that rebuilds them, shimmed the same for each valve? I always thought that new or used, usually the shims are not the same.

  • Colnta

Posted March 07, 2011 - 12:15 AM

#12

So, an update.

I got the transmission figured out, and put the case together. I found the balancer, drive gears and related nuts and washers in the pile, and managed to get everything lined up and torqued.

The shift level and related parts went together quickly as I'd dry fit everything previously, and it shifted without issue. After a little flipping through the manual I discovered that the last remaining gear was the kick start idle gear, so then I was able to use one more washer and clip from the pile.

Clutch went together as expected, and putting the crank case cover on used up a bunch of bolts; as did the clutch cover. My pile of parts was getting smaller. I then moved to the other side put the rotor etc. on. And with that all that was left was top end, which I expected to be pretty simple.

Since its been around -20C around here the last few weeks the garage was a little cold, so I decided to gather up the remaining parts and leave things organized for tomorrow night.... that is when I discovered a large dowel and o-ring... a dowel and o-ring that, after checking every page of the manual until I found it, go in the center of the case. So, I removed the clutch, idler gear, shift shaft and friends (tiny springs included), driver gears and balancer. I split the case and carefully cleaned the gasket material from all of the surfaces. Then, having gotten back to where I was three hours earlier, I dropped said dowel into its hole, and started the whole thing over again.

On the plus side, since I took it apart this time, every part is organized and it should only take an hour to put everything back together, but what a pain in the ass.

I'm sure nobody really cares, but it was so frustrating that I figured I'd make a post that maybe I can read someday. Maybe when I need a little perspective :thumbsup:

  • baxterj787

Posted March 07, 2011 - 12:22 PM

#13

I did a similar stunt once on an XR600. Had the motor back in the frame and plumbed up (oil lines, carb, exhaust) and saw one of those dowel pins...

Sounds like you are going in the right direction. If the valves are OEM and you are using a Yamaha manual, I think the manual will shed light as to which valve goes into each of the five ports.

Keep up the good work.

  • lumpy790

Posted March 08, 2011 - 10:57 AM

#14

All 5 of them the same size? From the factory, or from the previous owner, or another mechanic?

What sort of clearances did they yield?


Not all 5 the same but 3 intake same and the 2 exhaust were the same.





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