Horizons Unlimited - The HUBB

Horizons Unlimited - The HUBB (https://www.horizonsunlimited.com/hubb/)
-   Yamaha Tech (https://www.horizonsunlimited.com/hubb/yamaha-tech/)
-   -   Blown Head Gasket XT600 (https://www.horizonsunlimited.com/hubb/yamaha-tech/blown-head-gasket-xt600-82743)

jjrider 5 Aug 2015 03:27

'83 to '87,

I just can't comprehend why you'd buy another head.

ajax 5 Aug 2015 13:28

Quote:

Originally Posted by jjrider (Post 512349)
That's a '84-'85 jug.


Didn't you post about the valves being new or reworked on your current head ?

Before I got it, it had a cylinder,jug and timing chain replaced. I don't know if the valves were just cleaned up or there were replacements as well.

ajax 5 Aug 2015 20:07

I just can't comprehend why you'd buy another head.[/QUOTE]

Just want to get it running right. I've got 2 other bikes but look the must forward to driving the XT :)

JJRider let me know if I can send it to you? And what you need.

Or tell me what years I should look for on the head.

Best
Greg

Bobmech 6 Aug 2015 00:11

Quote:

Originally Posted by Bobmech (Post 512214)
IMO I think welding the head will soften the aluminium in that area, increasing the chance of future head gasket leakage, especially where the flame ring seals.
Once the welded area has been softened, there is also the risk of the exhaust valve seat next to it coming loose.

Bob

Hi Greg
regarding the above, & no offence to jjrider who is kind enough to offer you an option to fix your problem.

I'm an automotive mechanic, not an engine machinist.
But recently I asked a local very experienced & reputable engine machinist who does weld aluminium cylinder heads, if he could weld the gasket side/surface of an aluminium Honda 130HP outboard motor cyl head for me. And the above is what he told me. He said welding the head will reduce the hardness from 100 Brinell to approx 70 Brinell.

He didn't mention anything about the potential for valve seats coming loose, but that would depend on how hot the area around the valve seat gets & whether it gets softened/annealed when welding. Keep in mind the valve seats are an interference fit in the head.
And when a valve seat comes loose & falls out the result will usually cause serious damage to the piston, valve, & cyl head.

Bob

xtrock 6 Aug 2015 00:38

I really dont see the point shipping this, using hours of work when you can buy used one cheap and put it straight in. Then you never have to worry about new leak or valve seat problems.

ajax 6 Aug 2015 01:12

I get it, and really appreciate the input.
I'm just trying to confirm what head to get as the motor has been put back together with what years?
This is causing the delay as I probably let a good head with rocker box go last night (ebay) when it might of been a good head.

if someone could please look at previous picture from yesterday and confirm a jug to head combination I should be looking for.

Previous head was 1JK00
Jug on bike 34K00 Y1

jjrider 6 Aug 2015 15:12

Quote:

Originally Posted by xtrock (Post 512490)
I really dont see the point shipping this, using hours of work when you can buy used one cheap and put it straight in. Then you never have to worry about new leak or valve seat problems.


What are the chances a used head off Ebay will have good valves ? That was my point when asking about the valves in his current head, if they are good, why buy another head only to have questionable valves and seats. Now if his are bad/poor , different story. I've had to fix every used head I have gotten off Ebay, usually a reason the bike is being parted out, plus add in high miles with poor maintenance ect....

As to the welding, well everybody "knows it all " .I've done a few myself and know of quite a few that have been extensively reworked, all doing fine. People would be surprised at what is done to race engines to gain hp and they hold up. That said it would be a last option of course, if not needed no reason to. And yes, I HAVE been to college and went through metallurgy and welding . Did he ever say about the alloy used and the differences when welding?

I could have had this done and had 500 miles on the bike already, just frustrating trying to help and having the equipment and knowhow to do it and a lot of squibbling. I wasn't even considering charging for it other than return shipping.

xtrock 6 Aug 2015 19:36

Ok i understand, if this is done free of charge its no problem. I was thinking hours of work and shipping cost, it get pretty fast expensive even in your country i would assume. Give it a try, not many people left that helps out like you do JJ:thumbup1:

ajax 7 Aug 2015 03:23

I think its great to be able to get various opinions and advise.
I appreciate this very much :)
You guys are a wealth of knowledge and keep guys like me riding or at least dreaming it will be soon

ajax 18 Aug 2015 01:19

I'm going to keep an eye out for a head on ebay.
Can I use a TT head from the same years? Any issues? Any differences?

Thanks
Ex: Yamaha TT600 TT 600 Cylinder Head Assembly Camshaft Rocker Box Valve Cover | eBay

ajax 5 Sep 2015 03:21

Anyone know where I can get the gasket/o ring for the middle dowel on the head? Mine needs replacing.
I can order part but want to see if I might get an alternate gasket locally?
lYamaha 90430 08178 00 90430 08178 00 Gasket | eBay


All times are GMT +1. The time now is 07:09.


vB.Sponsors