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-   -   Blown Head Gasket XT600 (https://www.horizonsunlimited.com/hubb/yamaha-tech/blown-head-gasket-xt600-82743)

ajax 15 Jul 2015 21:16

Blown Head Gasket XT600
 
Hello

89 XT 600

Looks like head gasket.

Can I take off the head by tilting the motor forward or is it more complex. Anything that i should be looking at or thinking preventively?

Thanks
Greghttps://www.dropbox.com/s/gv5vd806t1...80161.MOV?dl=0

steveloomis 15 Jul 2015 21:37

Yes, tilting it forward will allow you to get the entire top end off. Don't forget to remove the rear bolt below the swing arm pivot. Also don't forget to remove the rocker box screws inside the valve setting cover area and the one on the top middle of the rocker box. The engine does tilt forward enough, been there done that....

ajax 16 Jul 2015 05:26

Thanks Steve

Any opinions on shopping for gasket.
OEM is like $45 shipped

Mezo 16 Jul 2015 08:27

Quote:

Originally Posted by ajax (Post 510640)
Thanks Steve

Any opinions on shopping for gasket.
OEM is like $45 shipped

Always OEM on the head gasket. :thumbup1:

Mezo.

ajax 18 Jul 2015 01:36

Pictures of head

1st time doing the replacement gasket so any advice would be great.

Thanks
Greghttps://www.dropbox.com/s/brxt3ji03s...-head.jpg?dl=0

ajax 18 Jul 2015 01:43

https://www.dropbox.com/s/brxt3ji03s...-head.jpg?dl=0

jjrider 18 Jul 2015 03:25

I had to laser out my own copper head gaskets to keep my hi-comp motor sealed up so the oem must be on the edge. Yours is an '89 so it does have the extra bolts, which is why they added it , I made the mistake of grabbing the older head so it has less bolts so I believe that's the main issue. For the valve cover, clean the two surfaces really good, but not with a razer blade. Make sure there are no scratches.
I use Permatex Moto-seal which was original made specifically for split case aluminum motorcycle engines. Works good , super clean and oil free surfaces are key to proper sealing.

With the head off, now is a good time to drill & tap that little plug on the front righthand side for a temp sensor. It is right above the right exhaust valve so picks up the hottest spot in the motor and quickly to keep an eye on it.

WeirdTim 18 Jul 2015 13:19

There's no need to tilt the engine in order to get the top end off on my 86.

Sent from my SM-G900V using Tapatalk

steveloomis 18 Jul 2015 15:37

humm, how'd you do that? Clearance needed to remove rocker box....

jjrider 18 Jul 2015 16:58

I played for quite a while to get one of mine off without moving the motor , never could get it so I took it out for full access. I've heard someone else saying of a very specific placement and way to do it but I never found it.



.

ajax 18 Jul 2015 17:40

What temp sensor are you using?
Was very mildly driven and definitely never over revved.
I can't find any warp or crack which leaves me confused as to what happened.
The leak was coming from right exhaust corner. But there is a mark/indent on surface. This seems to be more interior to valve and would still give a good mating surface for head. But I'm not sure.

xtrock 18 Jul 2015 18:58

The 90mod you can remove covers with engine on bolts, just remove intake boots. What is the marks on the head, seems deep scratch or just dirt? think you gonna have trouble with the gasket on these scratches.

Bobmech 19 Jul 2015 00:17

Those indents/deep scratches on the head are where the head gasket flame ring seals. You're going to have to get the head surface machined to fix the problem.
A good idea while the head is off is to lap the valves & renew the valve stem seals.

Bob

xtrock 19 Jul 2015 00:35

Quote:

Originally Posted by Bobmech (Post 510904)
Those indents/deep scratches on the head are where the head gasket flame ring seals. You're going to have to get the head surface machined to fix the problem.
A good idea while the head is off is to lap the valves & renew the valve stem seals.

Bob

Question is how much is possible to machine on this? seem pretty deep.

ajax 19 Jul 2015 01:13

If the scratches are to deep then what are my options. Ebay?

Any idea how that happened?

If it has to be milled down, will it change the engine characteristics (run worse)?


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