4T Top End Rebuild

[Aaron WildeMember]

Thanks for the tips Stuart. Why do they want you to torque the bolts then go 1/2 more? Is that to get a crush on the gaskets. I hate doing up bolts on bikes it feels like they are going to let go.I normally do it up till it strips, then back it off half a turn :laugh: Now I am trying to get the cam chain on the two cams and the chain is so tight I cant get it over them. The tensioner is not even on the bike :unsure: ! Once again the stupid manual does not say how difficult something is. example. Put the tire on the rim insert the mousse tube,then put the other bead in….. Yeah right. I would rather have a crappy book that actually told me how to do things than a really flash one with how to do it in four different languages.

[glennMember]

Cmon Aaron times running out mate :cheer: :cheer: no pressure mate :ohmy:

[Aaron WildeMember]

While I was doing all this I was unleashing a back up plan. Don’t worry Boony the black beast is serviced and ready to go.

[glennMember]

you are a devilish little thing are`nt you 👿 👿 👿 👿 :whistle:

[StuartMember]

Aaron wrote:

Quote:

Thanks for the tips Stuart. Why do they want you to torque the bolts then go 1/2 more? Is that to get a crush on the gaskets. I hate doing up bolts on bikes it feels like they are going to let go.I normally do it up till it strips, then back it off half a turn :laugh: Now I am trying to get the cam chain on the two cams and the chain is so tight I cant get it over them. The tensioner is not even on the bike :unsure: ! Once again the stupid manual does not say how difficult something is. example. Put the tire on the rim insert the mousse tube,then put the other bead in….. Yeah right. I would rather have a crappy book that actually told me how to do things than a really flash one with how to do it in four different languages.

Not sure how your doing the Cam chain bit, Have you got the cams installed? I found it doesn’t work this way, you need to have the cams out of the head, install the exhaust valve without caps installed then the inlet in a twisting sort of motion.

It may take a couple of goes to get the timing marks lined up. then install the caps once all is in place & lined up

The torque settings on the caps are minimal, I had my doubts as the are only just nipped up, needless to say my bike is still running (following Yamahas settings).

Your right about the manual, they have you flicking through for different steps, not just one simple A-Z of top end o/haul.

TB would be the man for explanation on stretching bolts for torque.

[RoyMember]

Get a two stroke Aaron, you know you want one!

[GlennMember]

sb_250y wrote:

Quote:

I would have thought the original titanium valves would of just needed a gring & Lap to go with the new seats

Stainless steel valves are ok to lap but avoid ginding or lapping your titanium valves. The reason you do not lap your titanium valves is because it removes the surface coating on the valve. If you lap them you will diminish the thickness or you can completely remove the hard surface. When replacing the valve seat it is important to have the valve seat cut in the correct position in relationship to the valve. Serdi or Newen valve and seat machines or a similar machine is a must, otherwise the valve will not sit on the seat correctly and you will forever have valve issues.

Remember that if you are replacing your titanium valves with stainless steel one’s you should also be looking at replacing your valve springs with heavier ones.

[Mick DMember]

blue450 wrote:

Quote:

sb_250y wrote:

Quote:

I would have thought the original titanium valves would of just needed a gring & Lap to go with the new seats

Stainless steel valves are ok to lap but avoid ginding or lapping your titanium valves. The reason you do not lap your titanium valves is because it removes the surface coating on the valve. If you lap them you will diminish the thickness or you can completely remove the hard surface. When replacing the valve seat it is important to have the valve seat cut in the correct position in relationship to the valve. Serdi or Newen valve and seat machines or a similar machine is a must, otherwise the valve will not sit on the seat correctly and you will forever have valve issues.

Remember that if you are replacing your titanium valves with stainless steel one’s you should also be looking at replacing your valve springs with heavier ones.

Knowing what you do for a living Blue450, I could very well suggest that people take note of what you have said in the above post.

[Aaron WildeMember]

Thanks for all the help guys got most back together just have to adjust a few shims. But now the job has taken back seat to a ride. This time there will be pics after my last dismal effort. I will take it all back now get in there and have a go yourself. Just make sure your bike is worth sub4k so if you have a stuff up you wont have to ring the banks :laugh:

[ScottMember]

Aaron wrote:

Quote:

I bought a ring compressor tool and it was too long because the stroke is so short.

Years ago on 2T triple cylinder jetskis, the easiest way to get the cylinder on was to use cable ties to compress the rings, Once the ring was in the cylinder the cable tie would drop down and you would just cut it to remove it.

Another alternative maybe?

[Aaron WildeMember]

[file name=Doc2.doc size=48640]http://www.obtrailriders.com/media/kunena/attachments/legacy/files/Doc2.doc[/file]

[Aaron WildeMember]

Well it is all back together. It went on the very first kick. So I was stoked. I kept thinking that I would have stuffed the timing up and I would wreck it when I kicked it over. The ride around the back yard was great.The feeling of riding something you had in bits all over the shed floor is great. The stock exhaust is whisper quiet and the power seems a lot smoother.I had a bit of trouble with one pad size on the middle intake valve. I kept thinking the measurement was .05mm but i think i was forcing it. My gut instinct ended right and i went down 2 pad sizes. This brought it down just under tollerance. Having to take the cams in and out to check afrer changing pads helped with confidence. Although at the time I wished i got it right the first time.I will check the the clearances now on my YZ with no hesitation. I think the wr could have done with a new crank so that will be my next mission. That will be huge. Don’t know if I or my wallet is ready for that just yet. Even if you have minimal mechanical experience you still should be able to check your valve clearances. Then if you feel confident enough change the pads to adjust them. If you want to save a big stuff up go as a team and get some help with someone who has done it before. At least it wont seem all wrong drinking on your own :laugh:

[Mick DMember]

Good one Aaron!! It is always a reief when something starts up after a rebuild. Wait untill you have six guys standing around drinking beers and waiting to hear it fire up for the first time. That puts the pressure on.

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