XS650.com
Forum Search: Advanced

Go Back   XS650 Forum > General Discussion > The Garage
Register Forum FAQ XS650 Tech Members List Search Today's Posts Mark Forums Read Donate

Welcome to XS650.com!
XS650.com is dedicated to the Yamaha XS650 twin motorcycles and to the people who love to ride, restore, and customize them. As a guest you can view the forum and photo galleries full of xs650 choppers, bobbers, trackers, cafe racers, and restorations, but you have to register before you can post or view attachments. Itís free and only takes a minute. Proceed to registration. (This notice will go away once you log in)

The Garage Motorcycle Related Discussion (Yamaha XS650, other makes and models, and anything else motorcycle related including tools and gear)

Reply
 
Thread Tools Search this Thread
Old 02-27-2011, 04:56 PM   #1
ReycleBill
Part Time Tyrannicide
 
ReycleBill's Avatar
 
Join Date: Dec 2010
Location: Greensboro, North Carolina
Posts: 1,824
Default What Causes Air Cooled Head Gaskets To Blow?

As I delve into my first effort to replace a blown head gasket on an XS 650 I'm pondering. I know that steam is most often the reason water cooled engines blow head gaskets but because our XS560s are air cooled I can't help but wonder what causes them to blow head gaskets in the hope that I can prevent future blown gaskets.

And please don't just say overheating is the cause because the result of overheating is most often piston seizure, not blown gaskets.

Any informed thoughts?


When the going gets tough the tough twist the throttle! Hard!
StolenMotorcycle.net helping you get your bike back in one piece!
ReycleBill is offline   Reply With Quote
Old 02-27-2011, 05:46 PM   #2
Jack
XS650 Addict
 
Jack's Avatar
 
Join Date: Jan 2010
Location: North carolina
Posts: 389
Default Re: What Causes Air Cooled Head Gaskets To Blow?

Engine studs are the main culprit,they're weak causing them to stretch and they're just plan to thin,along with that cushioning grommet they use to seal off prevent oil seepage past the studs.
Jack is offline   Reply With Quote
Old 02-27-2011, 06:06 PM   #3
CDNTX650
XS650 Guru
 
CDNTX650's Avatar
 
Join Date: Apr 2010
Location: Regina Sk. Canada
Posts: 1,745
Default Re: What Causes Air Cooled Head Gaskets To Blow?

check and re-torque every year.


2010 Kawasaki Versys
1974 TX650A resto modded and never done.
1985 KLR250.....time capsule with some light mods.
1993 KLR250...rough looking, but refreshed mechanically (wifes bike)
spare XS650 motor...slow build to 750 with a decent cam.
CDNTX650 is offline   Reply With Quote
Old 02-27-2011, 06:37 PM   #4
ReycleBill
Part Time Tyrannicide
 
ReycleBill's Avatar
 
Join Date: Dec 2010
Location: Greensboro, North Carolina
Posts: 1,824
Default Re: What Causes Air Cooled Head Gaskets To Blow?

Jack and CDNTX650, Thanks, that's something I can chew on.


When the going gets tough the tough twist the throttle! Hard!
StolenMotorcycle.net helping you get your bike back in one piece!
ReycleBill is offline   Reply With Quote
Old 02-27-2011, 07:09 PM   #5
ReycleBill
Part Time Tyrannicide
 
ReycleBill's Avatar
 
Join Date: Dec 2010
Location: Greensboro, North Carolina
Posts: 1,824
Default Re: What Causes Air Cooled Head Gaskets To Blow?

Next question: How do I get my hands on a set of high performance head studs?


When the going gets tough the tough twist the throttle! Hard!
StolenMotorcycle.net helping you get your bike back in one piece!
ReycleBill is offline   Reply With Quote
Old 02-27-2011, 07:42 PM   #6
CDNTX650
XS650 Guru
 
CDNTX650's Avatar
 
Join Date: Apr 2010
Location: Regina Sk. Canada
Posts: 1,745
Default Re: What Causes Air Cooled Head Gaskets To Blow?

not sure of that, i just re-torque till i get constant readings after a re-build...then once a year.


2010 Kawasaki Versys
1974 TX650A resto modded and never done.
1985 KLR250.....time capsule with some light mods.
1993 KLR250...rough looking, but refreshed mechanically (wifes bike)
spare XS650 motor...slow build to 750 with a decent cam.
CDNTX650 is offline   Reply With Quote
Old 02-28-2011, 03:19 PM   #7
ReycleBill
Part Time Tyrannicide
 
ReycleBill's Avatar
 
Join Date: Dec 2010
Location: Greensboro, North Carolina
Posts: 1,824
Default Re: What Causes Air Cooled Head Gaskets To Blow?

Here's what I've learned thus far:

The factory head studs are not up to doing the job. The racers used to make their own but the treating of metals is a little over my head-- does anyone sell high performance head studs for XS650s.

Studs need to be kept at proper torque settings.

Head gaskets on air cooled engines do not blow because of overheating. But, detonation (spark knock) will cause overheating and sometimes blown head gaskets. Detonation is caused by any or all of the following: timing advanced too high, Air-fuel mixture set too lean, too little air flow. We must be careful not to confuse cause with effect. Detonation causes blown head gaskets-- overheating is a common symptom (effect) of detonation.

Detonation can also cause lots of things worse than blown head gaskets.

Loud pipes might save lives but loud pipes kill perfectly good engines by hiding the sounds of detonation. (Makes me glad I got rid of that 2-1 header and megaphone that came on my bike when I bought it.)

That said, another cause of detonation can be overheating. Detonation causes overheating and overheating causes detonation. Cause and effect sometimes intermingle.

An oil cooler is a must. Check!

Directing more air flow to the head is a must. A chin scoop and lowers attached to my new crash bars are planned.

An oil temperature gauge would be smart.

And finally, getting the engine out of the frame is a B&*&! when you've already got a hernia (busted nut.) I'm not looking forward to wrestling it back in.


When the going gets tough the tough twist the throttle! Hard!
StolenMotorcycle.net helping you get your bike back in one piece!
ReycleBill is offline   Reply With Quote
Old 02-28-2011, 03:28 PM   #8
DLD1
Mechanical Stuff Nut
 
DLD1's Avatar
 
Join Date: Nov 2010
Location: Tracy, Ca
Posts: 331
Default Re: What Causes Air Cooled Head Gaskets To Blow?

Replace those sealing washers that have rubber in them with good copper washers, they will seal fine and hold the torque better.

DLD1
DLD1 is offline   Reply With Quote
Old 02-28-2011, 03:43 PM   #9
Travis
Staff Member
 
Travis's Avatar
 
Join Date: Aug 2009
Location: River Falls, WI, USA
Posts: 3,875
Default Re: What Causes Air Cooled Head Gaskets To Blow?

Are the head studs really too thin? I haven't heard anyone complain that they are having problems with them stretching or anything.


- Travis
Travis is online now   Reply With Quote
Old 02-28-2011, 04:33 PM   #10
ReycleBill
Part Time Tyrannicide
 
ReycleBill's Avatar
 
Join Date: Dec 2010
Location: Greensboro, North Carolina
Posts: 1,824
Default Re: What Causes Air Cooled Head Gaskets To Blow?

Quote:
Originally Posted by Travis View Post
Are the head studs really too thin? I haven't heard anyone complain that they are having problems with them stretching or anything.
In my opinion, the fact that they must be re-torqued most every year indicates they are less than they could be.


When the going gets tough the tough twist the throttle! Hard!
StolenMotorcycle.net helping you get your bike back in one piece!
ReycleBill is offline   Reply With Quote
Old 02-28-2011, 04:34 PM   #11
ReycleBill
Part Time Tyrannicide
 
ReycleBill's Avatar
 
Join Date: Dec 2010
Location: Greensboro, North Carolina
Posts: 1,824
Default Re: What Causes Air Cooled Head Gaskets To Blow?

Quote:
Originally Posted by DLD1 View Post
Replace those sealing washers that have rubber in them with good copper washers, they will seal fine and hold the torque better.

DLD1

Now I must check to see which I ordered.


When the going gets tough the tough twist the throttle! Hard!
StolenMotorcycle.net helping you get your bike back in one piece!
ReycleBill is offline   Reply With Quote
Old 02-28-2011, 05:28 PM   #12
retiredgentleman
XS650 Guru
 
retiredgentleman's Avatar
 
Join Date: Jan 2010
Location: Calgary Alberta, Canada
Posts: 4,105
Default Re: What Causes Air Cooled Head Gaskets To Blow?

This link has a ton of good information:
http://xs650temp.proboards.com/index...lay&thread=327

Copper washers work very well on the large studs. Proper torqing is super important, and retorqing after the engine has been run. Make sure you have a good torque wrench.

Removing or re-installing an engine is a 2 person job. It weighs 165 lbs................why would you want to injure yourself by doing it solo???? A couple of pipes and some nylon slings makes engine handling a piece of cake.
Attached Thumbnails
Engine Removal.JPG  


78SE, Pamco Ignition with E-advancer and Accel #140403S Coil, dual bridge rectifiers, VR-115 regulator, LED tail/brake, BS38 carbs, OEM air boxes, OEM manifolds, OEM exhaust, Heiden Oil filter/cooler, 17/33 gearing, analog voltmeter, Brembo 4 piston calipers front and rear, "All Balls" roller steering bearings
retiredgentleman is offline   Reply With Quote
Old 02-28-2011, 05:48 PM   #13
ReycleBill
Part Time Tyrannicide
 
ReycleBill's Avatar
 
Join Date: Dec 2010
Location: Greensboro, North Carolina
Posts: 1,824
Default Re: What Causes Air Cooled Head Gaskets To Blow?

Quote:
Originally Posted by retiredgentleman View Post
This link has a ton of good information:
http://xs650temp.proboards.com/index...lay&thread=327

Copper washers work very well on the large studs. Proper torqing is super important, and retorqing after the engine has been run. Make sure you have a good torque wrench.

Removing or re-installing an engine is a 2 person job. It weighs 165 lbs................why would you want to injure yourself by doing it solo???? A couple of pipes and some nylon slings makes engine handling a piece of cake.
Great stuff there. I find it interesting that the subject of PCV (Positive Crankcase Ventilation) was mentioned as I've been wondering if this could be a possible cause (additional factor?) of blown gaskets.

And the photograph will be remembered always.


When the going gets tough the tough twist the throttle! Hard!
StolenMotorcycle.net helping you get your bike back in one piece!
ReycleBill is offline   Reply With Quote
Old 02-28-2011, 06:22 PM   #14
rwingsfan
Xs 650 Dummy
 
rwingsfan's Avatar
 
Join Date: Nov 2010
Location: Warm Ioway
Posts: 557
Default Re: What Causes Air Cooled Head Gaskets To Blow?

Quote:
Originally Posted by retiredgentleman View Post

Removing or re-installing an engine is a 2 person job. It weighs 165 lbs................why would you want to injure yourself by doing it solo???? A couple of pipes and some nylon slings makes engine handling a piece of cake.
I put mine in and out by myself most of the time, really not that hard. You do not have to gorrilla it either. I put it on a jack rollit over beside the bike grab on and put her in laterally. Course no one ever confused me with a smart person.


2012 Harley Road Glide
1980 Harley Shovelhead
1997 Mustang convertible
rwingsfan is offline   Reply With Quote
Old 02-28-2011, 06:27 PM   #15
CDNTX650
XS650 Guru
 
CDNTX650's Avatar
 
Join Date: Apr 2010
Location: Regina Sk. Canada
Posts: 1,745
Default Re: What Causes Air Cooled Head Gaskets To Blow?

Quote:
Originally Posted by Travis View Post
Are the head studs really too thin? I haven't heard anyone complain that they are having problems with them stretching or anything.
I don't think so. I just check head bolt torque as part of my yearly look over.


2010 Kawasaki Versys
1974 TX650A resto modded and never done.
1985 KLR250.....time capsule with some light mods.
1993 KLR250...rough looking, but refreshed mechanically (wifes bike)
spare XS650 motor...slow build to 750 with a decent cam.
CDNTX650 is offline   Reply With Quote
Old 02-28-2011, 07:05 PM   #16
xschris
rock and roll man!
 
xschris's Avatar
 
Join Date: Feb 2011
Location: finger lakes of new york state
Posts: 403
Default Re: What Causes Air Cooled Head Gaskets To Blow?

pulled my engine by myself, of course i had beer power!


1979 xs400 1980 xs400sg 1989 sh50 razz
xschris is offline   Reply With Quote
Old 02-28-2011, 07:21 PM   #17
MacMcMacmac
Murdercyclist
 
MacMcMacmac's Avatar
 
Join Date: Mar 2010
Location: Ottawa,Canada
Posts: 124
Default Re: What Causes Air Cooled Head Gaskets To Blow?

I pulled a Seca Turbo motor by myself. It was a heavy bastard.

Depending on the thread pitch and length, you might check and see if some of the high perf dragbike engine studs from APE performance could be used. Might not be the cheapest route, but they are about the strongest studs you will find.
MacMcMacmac is offline   Reply With Quote
Old 02-28-2011, 07:30 PM   #18
XSLeo
XS650 Guru
 
XSLeo's Avatar
 
Join Date: Jan 2010
Location: Lebanon NY
Posts: 9,619
Default Re: What Causes Air Cooled Head Gaskets To Blow?

If you click tech at the top of the page and scroll down to homemade tools, browse the tools you will find several ideas on engine removal tools. I like the u-shaped, long handled tool that you hang from the ceiling. I think you could use it across a wheeled office chair too.


The only way you can find out if you can do something is to try.
75 XS650B with a few mods, Dual disc brakes up front, Disc on rear, Pamcopete Ignition with the green coil, Radio Shack rectifier and Chrysler regulator, LED tail/brake and turnsignals. 750 kit,1.5 headepipes, Emgo shorty mufflers.
XSLeo is offline   Reply With Quote
Old 02-28-2011, 07:34 PM   #19
ReycleBill
Part Time Tyrannicide
 
ReycleBill's Avatar
 
Join Date: Dec 2010
Location: Greensboro, North Carolina
Posts: 1,824
Default Re: What Causes Air Cooled Head Gaskets To Blow?

Quote:
Originally Posted by MacMcMacmac View Post
I pulled a Seca Turbo motor by myself. It was a heavy bastard.

Depending on the thread pitch and length, you might check and see if some of the high perf dragbike engine studs from APE performance could be used. Might not be the cheapest route, but they are about the strongest studs you will find.
So does anyone know the thread pitch, length and other dimensions-- I've not yet opened mine up.


When the going gets tough the tough twist the throttle! Hard!
StolenMotorcycle.net helping you get your bike back in one piece!
ReycleBill is offline   Reply With Quote
Old 02-28-2011, 09:02 PM   #20
Punkskalar
Hugh's HandBuilt
 
Punkskalar's Avatar
 
Join Date: Jun 2010
Location: Asheville, NC
Posts: 1,989
Default Re: What Causes Air Cooled Head Gaskets To Blow?

Bill,

Contact ARP with the measurements you need. They will set you up with some headstuds that won't go ANYWHERE. I've used their studs on all kinds of things in the past that "stock" was not good enough for.


Tech - Creative Fabrication - http://hughshandbuilt.blogspot.com/
Website - http://hughshandbuilt.com/

*There is never a charge for Tech Support even if you don't purchase from us - We are Enthusiasts Helping Other Enthusiast and that is just the way it is
Punkskalar is offline   Reply With Quote
Reply


Similar Threads (based on keywords)
Thread Thread Starter Forum Replies Last Post
Exhaust gaskets Downer The Garage 4 12-17-2010 05:44 PM
For Sale - NEW carb bowl gaskets for 79 XS 650 camo Classifieds 2 12-01-2010 01:34 PM
Yamabond on top and bottom of gaskets? rodemyyamaha The Garage 3 10-23-2010 06:29 PM
gasket and sealer or just gaskets WacoBrian The Garage 3 07-18-2010 01:48 PM
Engine/Crankcase Gaskets? cheftay The Garage 5 02-25-2010 12:27 PM

Tags
engine

Bookmarks
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 10:59 PM.