XS650 Top End Buildup

QUESTION: did the ‘73 TX650 actually have one of those baffles?

I know that the later bikes do - but this is a fairly early 256 engine model......
 
The head off of my XS2 did not have that baffle when I pulled it off, and I’m quite certain I was the first one in there since the factory built it. I reassembled it with out it.
View attachment 149469

Ya beat me to it by THAT much Mailman....
 
Going by Partzilla's parts catalogues, 74 was the first year Yamaha put that little breather baffle in the head. 73 and earlier diagrams don't show it.
 
I've got a 73 head and it has no baffle.

Edit: A spare 73 head.
 
OK - I suspect that leaving it out is not a big deal.

All that will happen is that you might get more flow out of the crankcase breather tubes.
 
Yamaha did get complaints from some owners about too much oil or oil vapor coming out of the breather on the earlier models. They took various steps over the years to try and reduce it. This baffle was probably one of them.
 
Yamaha did get complaints from some owners about too much oil or oil vapor coming out of the breather on the earlier models. They took various steps over the years to try and reduce it. This baffle was probably one of them.
Thanks for the info. I must admit that I was having trouble believing that it was a vital part.
 
If a person uses the orange Permatex spray on the head gasket. Then waits 30 minutes, before putting it in place. How much time do you have to rivit the cam chain link and get ready to torque everything down?

I'm just wondering if I should buy some extra links, before even starting?
 
No need to rush, I've sprayed head gaskets with Permatex copper spray as much as a week ahead of use. No need to go all AR on cam chain riveting. The pins don't have to be pretty, they just need to be mashed out enough to hold the plate on, and not mashed down to the point of binding. On that job, it's harder to screw up than it is to get it right. If that sounds too good to be true, do a search for cam chain fails--I can't recall ever seeing a failed installation on an XS650 or even reading about one!
 
This picture shows what looks like factory sealant applied on either end Of the timing chain tunnel on the head gasket. I think I have read others mention that too on this forum. Is a little smear of Yamabond 4 suitable... or would Permatex Super black be better? I will be using an NOS Yamaha Original head gasket.
 
I don't see a pic. If you're talking about the head gasket, the copper spray is all you need.
 
About any sealant will work, with varying degrees of longevity as long as you coat both sides all the way around the gasket.
 
I'm not going to cover the whole gasket with ThreeBond, I can understand doing that if you are using spray copper. Maybe somebody will chime in on using a little dab at the front and rear of the timing chain tunnel where oil fling is pronounced.
 
I'm not going to cover the whole gasket with ThreeBond, I can understand doing that if you are using spray copper. Maybe somebody will chime in on using a little dab at the front and rear of the timing chain tunnel where oil fling is pronounced.
A dab at the front and rear might work just fine. Covering the whole thing is prolly about 50 cents worth of sealant. Seems pretty cheap insurance in my opinion. Your engine to do as you please, but I'm not sure I understand why you want to scrimp on sealant?
 
No knowledge here but hylomar?
Farm and fleet has spray copper for $7.50
https://www.google.com/search?q=spr...ome..69i57.12549j0j4&sourceid=chrome&ie=UTF-8
From a chevy small block forum but seems like good advice all around:

I install them dry on brand spanking new engine builds all the time with no issues at all. Usually the surface finish on what I'm working on is 13RA, which is within the range of what is necessary for a MLS gasket to seal (<50RA). Not all engines or heads are machined that good. I will check a random stock engine to compare, but they do vary a bit visually.

Now with used components, I go about things a bit differently. On an "unmachined" deck or cylinder head surface (such as a cylinder head install) that I may question the sealing ability, I have used copper spray with great success. I have used hylomar also. Both work to seal the cooling system from dripping externally if there is a machining discrepancy.

Things that have worked for me in the past for cleaning both cylinder heads and the deck surface:

The stock MLS gaskets are cake to clean, the OEM graphite are a PITA. Clean off as much gasket material as possible with a scraper or by CAREFULLY using a razor blade. Then use a gasket removal spray to remove the last bits. Let the chemical soak then wipe the material off using rubber gloves and paper shop rags. Clean with brake/carb cleaner several times. If there is some graphite material left that cannot be removed, you can use some scotchbrite soaked in WD40 or cleaning solvent to polish that off.
 
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