plane_ben
XS650 Junkie
Hope it works out for you and your head is not warped.
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ANLAF
XS650 Guru
Thanks, plane_ben.
Fellers, I am uploading a video at the moment. Interesting developments.
Anlaf
Fellers, I am uploading a video at the moment. Interesting developments.
Anlaf
ANLAF
XS650 Guru
Here is the revealing video.
Anlaf
Anlaf
ANLAF
XS650 Guru
NONclow, thanks for the run down on valve guides - what do you think of the head gasket video?
Anlaf
Anlaf
You didn't follow the "Leakless XS Assembly" tips that many of us use. Those consist of adding narrow beads of sealer to both sides of the head gasket around the cam chain tunnel, the 4 outside stud holes (the ones that flow oil), and as added insurance, across the front between the outer stud and the cam chain tunnel. Like so .....
The head gasket was installed dry by the factory but that was 30 years ago when the parts were factory fresh and new. Today, a little added insurance to make sure things seal isn't a bad idea. This pic that I "doctored" is from eBay of a new factory head gasket. Note the shiny areas on the gasket at the top and bottom of the cam chain tunnel. That is factory applied sealer so as you can see, a factory gasket came with some sealer in what Yamaha probably figured were critical areas. Note they pretty much correspond to where your untreated gasket gave way.
The head gasket was installed dry by the factory but that was 30 years ago when the parts were factory fresh and new. Today, a little added insurance to make sure things seal isn't a bad idea. This pic that I "doctored" is from eBay of a new factory head gasket. Note the shiny areas on the gasket at the top and bottom of the cam chain tunnel. That is factory applied sealer so as you can see, a factory gasket came with some sealer in what Yamaha probably figured were critical areas. Note they pretty much correspond to where your untreated gasket gave way.
looks like you've found the culpret Anlaf.
I'm thanking my lucky stars that I put yamabond all round my camchain tunnel .
I suspect that these head gaskets we are getting in the gasket sets are poor quality .
Before I put my head on I resurfaced it on some wet and dry on my window sill. Nothing elaborate but it highlighted a huge warping in the head between the two sides across the camchain tunnel.
The cam chain tunnel surface was at least 0.5mm below the rest of thre head.!
It took quite a lot of sanding to get it flat so I'm hoping it will hold when I start it up next week.
4th time lucky eh !?
I'm thanking my lucky stars that I put yamabond all round my camchain tunnel .
I suspect that these head gaskets we are getting in the gasket sets are poor quality .
Before I put my head on I resurfaced it on some wet and dry on my window sill. Nothing elaborate but it highlighted a huge warping in the head between the two sides across the camchain tunnel.
The cam chain tunnel surface was at least 0.5mm below the rest of thre head.!
It took quite a lot of sanding to get it flat so I'm hoping it will hold when I start it up next week.
4th time lucky eh !?
looks like you've found the culpret Anlaf.
I'm thanking my lucky stars that I put yamabond all round my camchain tunnel .
I suspect that these head gaskets we are getting in the gasket sets are poor quality .
Before I put my head on I resurfaced it on some wet and dry on my window sill. Nothing elaborate but it highlighted a huge warping in the head between the two sides across the camchain tunnel.
The cam chain tunnel surface was at least 0.5mm below the rest of thre head.!
It took quite a lot of sanding to get it flat so I'm hoping it will hold when I start it up next week.
4th time lucky eh !?
Peanut, that is extraordinarily warped! Glad you caught and addressed this. Back in the day, we would occasionally find a warped surface, but never much over .005", even on 4-cyl heads. It seems that with age and mileage, these engines are displaying anomalies beyond the scope of traditional old-school wrenching.
The sealer dams/rings in 5Twins' headgasket pics remind me of the modified Fel-Pro headgaskets used successfully in the ill-fated Chevy Vega 4-cyl engine, whose non-deck unsupported aluminum cylinders would crush themselves trying to expand against a cast-iron head, only to shrink back about .020" when cool, allowing water incursion.
A note on lapping/resurfacing heads/cylinders: An old-school training regimen used on beginners and apprentices in the art of filing and sanding was to teach and challenge the student to be able to produce perfectly flat surfaces on wood and metal. Invariably, the student would produce a slightly convex surface, partly because of hand control, and partly because the abrasive has better 'purchase' on the outer edges of the workpiece, especially if the abrasive is slightly flexable, like sandpaper.
Resurfacing an XS650 head or cylinder on a perfectly flat plate with wet-or-dry will produce this convex edge, but no where near enough to worry about, so that's fine. In really critical situations, we would prefer the lap compound instead.
Of course, having a good machine shop with properly sharpened cutters take a skim off the surface is the best method.
Coupla final thoughts: Try assembling the head on the cylinder, with the alignment dowels in place, but without the headgasket, and see if there's any gap between the head and cylinder. And check for unblocked/clean camshaft region drainback openings that pass thru the head.
ANLAF
XS650 Guru
Fellers, glad you think I have found the fault with the gasket - it all makes sense.
5twins, I did apply sealant, but thinking back it was a very thin film of local generic stuff from Halfords. I will look out for some Yamabond or similar.
Anyone any recommendations?
I will not be able to get to the bike for a few days - I am having surgery on the old left cylinder... i mean knee, today, but I can order the recommended sealant in time for my return to the smallest workshop.
All your contributions are very much appreciated as usual.
Anlaf
5twins, I did apply sealant, but thinking back it was a very thin film of local generic stuff from Halfords. I will look out for some Yamabond or similar.
Anyone any recommendations?
I will not be able to get to the bike for a few days - I am having surgery on the old left cylinder... i mean knee, today, but I can order the recommended sealant in time for my return to the smallest workshop.
All your contributions are very much appreciated as usual.
Anlaf
NONclow
Confirmed Laquer Breather
It might be contrary to the popular method, but I don't use any form of sealant on head gaskets, although I would get both surfaces trued up (lapping the head, check the cyls with the straigtedge too). I would also inspect the inside of the guides for micro scratches, and the inside lip of the stem seals. Bummer the head was already cleaned in the video. Was there any excess build up of oil around the valve springs like an oil drain passage was blocked? How about the guide to head connection? Maybe sucking oil from around the guide?
EDIT: I don't use sealant on HEAD gaskets, but I do use permatex on other gaskets....no sillycone anywhere in my motor
, check the cyls with the straigtedge too). I would also inspect the inside of the guides for micro scratches, and the inside lip of the stem seals. Bummer the head was already cleaned in the video. Was there any excess build up of oil around the valve springs like an oil drain passage was blocked? How about the guide to head connection? Maybe sucking oil from around the guide?EDIT: I don't use sealant on HEAD gaskets, but I do use permatex on other gaskets....no sillycone anywhere in my motor
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I am Carbon
shade tree mechanic
good luck on the surgery Brother.
I don't what people think here but I am prepared to use Permatex aviation Form-A-Gasket sealant liquid on my engine rebuild. I know the it works great on VWs to keep them from leaking
I don't what people think here but I am prepared to use Permatex aviation Form-A-Gasket sealant liquid on my engine rebuild. I know the it works great on VWs to keep them from leaking
Please don't misconstrue any of my old-school admonitions as gospel, they all come outta that wayback machine. Headgaskets were a particularly challenging issue during that time at H*nda. We were getting mixes of gasket styles, from standard dry composition, some coated with a dusty/flaky graphite material, and various forms of 'sticky' gaskets. What a mess. Sealants/adhesives were frowned upon because of unreliable/unpredictable results (especially with 'graphite' headgaskets), and the infancy of the chemistry, and possible damage to the engine trying to get it apart later.
After 40 years of product development and proof-in-the-field testimonies, adhesive/sealants have come a long way. Not so sure about chinese gaskets though.
The 'leakless' headgasket method referred to by 5Twins has evidently a long period of success. That same type of solution saved many a Vega engine...
After 40 years of product development and proof-in-the-field testimonies, adhesive/sealants have come a long way. Not so sure about chinese gaskets though.
The 'leakless' headgasket method referred to by 5Twins has evidently a long period of success. That same type of solution saved many a Vega engine...
I am Carbon
shade tree mechanic
Oh what a dirty joke the Vega engine was on mankind.
Mine made a fantastic boat anchor, after I swapped-in a 327...
When I bought my 78SE, 7 years ago, it was using a lot of oil and puting out puffs of black smoke from both exhausts. Plugs would blacken quickly. It started and ran just fine, so I drove it that way for the first year.
I took the top-end apart after the first season, and found the head gasket was passing oil from the camchain tunnel. Here's a couple of pics that show what can happen, when oil is sucked into the cylinders......................its ugly!
Applying a thin bead of gasket sealant (I used 3bond 1104), as shown in 5twins picture, is a "must do" on these engines. So after 6 seasons now, my engine uses no oil, and plugs stay a tan colour.
I took the top-end apart after the first season, and found the head gasket was passing oil from the camchain tunnel. Here's a couple of pics that show what can happen, when oil is sucked into the cylinders......................its ugly!
Applying a thin bead of gasket sealant (I used 3bond 1104), as shown in 5twins picture, is a "must do" on these engines. So after 6 seasons now, my engine uses no oil, and plugs stay a tan colour.
Attachments
ANLAF
XS650 Guru
Just back from my surgery - I can straigten and bend my knee properly. Might sting a bit when the morphine wears off, but success - now back to the bike.
By what you fellers are saying, and those horror pics from, I have no doubt that it is cam chain channel to left cylinder ingress through the weaknesses in the head gasket. Interesting to know the different types of gaskets used - this one (my third) dies not have any coating on, but the thin smattering of sealant I used came off very easily.
I will get my hands on one of the recommended types of sealant and put the bike back together - I will video as I go, and if it is a success, and the bike runs as it should, then that video may be of help to others.
Anlaf
By what you fellers are saying, and those horror pics from, I have no doubt that it is cam chain channel to left cylinder ingress through the weaknesses in the head gasket. Interesting to know the different types of gaskets used - this one (my third) dies not have any coating on, but the thin smattering of sealant I used came off very easily.
I will get my hands on one of the recommended types of sealant and put the bike back together - I will video as I go, and if it is a success, and the bike runs as it should, then that video may be of help to others.
Anlaf
ANLAF
XS650 Guru
Fellers, so far sealant recommendations are:
Yamabond (Peanut)
Permatex (NONclow)
Permatex aviation Form-A-Gasket (Carbon)
3bond 1104 (Retiredgentleman)
and what is the verdict on Hylomar or Hylomar Blue?
Anlaf
Yamabond (Peanut)
Permatex (NONclow)
Permatex aviation Form-A-Gasket (Carbon)
3bond 1104 (Retiredgentleman)
and what is the verdict on Hylomar or Hylomar Blue?
Anlaf
The last time I used Hylomar was around 1983, on some top end work. I was working in a power plant at the time, and the mechanics always used Hylomar when mating surfaces. They highly recommended it and supplied me with a tube. I was impressed by the "licensed from Roll-Royce" on the side of the tube.
Its high quality for sure. IIRC there's medium and heavy grades of Hylomar.
Not sure if 3bond 1104 is still around..................or is it 3bond 1194 now???
I am Carbon
shade tree mechanic
a couple places in Asia sill have 1104
RG it's 1184 now
ThreeBond 1184 is a semi-drying liquid gasket whose major component is special synthetic rubber. After it is applied and dried, it will form a rubber-like elastic body. Since it excels in padding property, it shows a high sealing effect on bonded surfaces that have poor flatness and large clearance. In addition, it has excellent resistance to water, oil and gasoline.
Direct replacement for:
•Threebond 1104 (Discontinued because of hazardous chemicals)
•Threebond 1194 (Discontinued because of hazardous chemicals)
•Honda Bond
•YamaBond 4
• Suzuki 99000-31010
•Kawasaki Bond 56019-120
RG it's 1184 now
ThreeBond 1184 is a semi-drying liquid gasket whose major component is special synthetic rubber. After it is applied and dried, it will form a rubber-like elastic body. Since it excels in padding property, it shows a high sealing effect on bonded surfaces that have poor flatness and large clearance. In addition, it has excellent resistance to water, oil and gasoline.
Direct replacement for:
•Threebond 1104 (Discontinued because of hazardous chemicals)
•Threebond 1194 (Discontinued because of hazardous chemicals)
•Honda Bond
•YamaBond 4
• Suzuki 99000-31010
•Kawasaki Bond 56019-120
