Honda CX 500 Forum banner
1 - 20 of 70 Posts

·
Registered
Joined
·
40 Posts
Discussion Starter · #1 ·
Well my wet plugs have gotten much worse, its not gasoline, but coolant. While checking for spark my hand got damp when near the open spark plug hole, so its leaking pretty bad. Not gonna travel any further in this condition.



Just curious how hard it is to replace head gaskets under a tree with pretty basic tools??



Will check out this afternoon if and when I can get a parts kit. My manual says that head gaskets can be done without dropping the engine out of its cradle so before I give up on my trip I am gonna seriously look into doing my own repairs.





Should I decide to do headgaskets are there any tips more experienced GL/CX owners have to share?

Type of gasket kit I should ask about?

Other maintenance to do while I have the bike in this stage of dissassembly??

How likely is it that I could have a cracked head???



Won't know till I pull them of course but that could settle wether I make repairs or not.





I'm nearly 1500 km into a 7500 km trip so I am not sure what to do yet, I may abort this adventure and catch the bus home. However I am staying at a friends place and he and his family say I am welcome to stay and make repairs so that will be my first choice.





Lots to do while waiting in this mountain town, so will keep busy rock climbing, rafting, mtn biking, etc, while waiting for parts, (if I choose to make repairs)







Anyways I will check back tonight and hope I can get some guidance by those who "have been there"









If repairs are not feasable there will be a 1982 GL500 Silverwing Interstate in good condition, (but needs head gaskets), that will avaliable for cheap.
 

·
Registered
Joined
·
7,223 Posts
Well, getting the heads off can be done on the bike. The main thing with head gaskets is you get a set that are made with gasket material AND metal. There should be a ring around the cylinder made of metal on the gasket (you will see what i mean when you remove the heads). There are a couple of things you can check while waiting for parts.



1 - Check the oil and see if there is any coolant in it. If it has been leaking a while the oil will look creamy/foamy. If it is it is best you DONT ride the bike until the engine can be cleaned out. It is possible to do this if the bike can be made to run after new head gaskets by draining all the oil, putting new stuff in, running the bike up to operating temp for about 15 min, then drain the oil again and refill.



To remove the heads, you will have to remove the rocker bolts and two more inside the top of the head. The heads have two dowel pins used as passages for coolant, which makes getting the heads off a bit of a pain (must pull stright up). I find it easiest to get a wide knife blade (i prefer the really big olfa knife blades, the one about an inch thinc where you can break off dull bits) and using a hammer tap it STRAIGHT into the gasket seam. If you keep the blade straight, the angle on the blade will be too acute to even contact the mating surfaces. Tap it in about 1/2" then remove and move along the seam. By the time you get about 1/2 way in the head gasket will let go. Then gently pry up on the head to get it to clear the dowels (and make sure BOTH are there). Then;



2 - Check the heads when you get them off for cracks or any sign of where the leak was comming from. It may show along the gasket area, from a coolant hole (dowels) or due to a crack in the head.



3 - Check what the valve faces look like, color and shape. They can reveal a lot about what went on.



4 - Check the cylinder jacket (inside surface of the cylinder wall for any signs of cracking or damage.



If its a blown gasket, then you may be fine based on how much got in the oil. The heads and cylinder can be cleaned up to remove all the coolant residue, then pour enough oil on the pistons to cover them as best you can (cant get it all due to the cylinder angle). Swish the oil around so it goes down all around the whole piston circumference. Turn the crank by hand via the front bolt and listen to the pistons as they move. Any "grating sound" is not good, but if they sound smooth and noise free keep rotating until the cylinder walls are all coated.





Let us know how you make out, as about 70% of the time is just a blown head gasket, while the remaining 30% would be cracked head/cracked jacket/missing dowel.
 

·
Registered
Joined
·
717 Posts
Repairing the gasket is a lot easier than most other engines simply because the heads are exposed and easy to get to. So long as you use a quality head gasket , preferably OEM Honda , it can be done with no special tools. I doubt if you have a cracked head so do not worry too much on that score. Try and use decent sockets and a torque wrench if you can get your hands on one. If not then just exercise caution and do NOT over-tighten , you risk stripping the threads.

Good luck and try not to be frightened - it is not as hard a job as you think.
 

·
Registered
Joined
·
161 Posts
OEM Honda head gaskets and the oil passage O-rings.



I've done head gaskets in an afternoon, but it was to replace the aftermarket ones I'd used with OEM Honda ones, so I didn't have to spend a lot of time cleaning up the gasket mating surface.



You may as well order new dowel pins while you're at it.



While you're waiting for the parts to arrive, get a package of new razor blades and some cotton clothes line from the hardware store.



Pull and label the bolts and rocker assembly and use a wooden dowel down the plug hole to find the bottom of the stroke. Feed in as much clothes line as you can and slowly turn the engine using bolt behind the front inspection cover. Head should come off with no fuss.



Now spend some quality time cleaning the gasket surfaces. Clean all the oil out of each of the head bolt holes.



When you reinstall the oil passage O-rings, use a bit of grease to hold them in place. Put anti-seize on the dowel pins.
 

·
Registered
Joined
·
191 Posts
A torque wrench is the closest thing to a specialty tool you will need
 

·
Premium Member
Joined
·
2,510 Posts
I hate to throw cold water on this, but that task is not something I would want to tackle without a good place to work on the bike and plenty of time.



I've heard the heads can be removed with the engine in the bike but I think it would be much easier to pull the engine, especially on the Interstate. There's lots of things in the way that would no longer be a problem with the engine out.



You might try to re-torque the heads first before going getting into lots of work. You may get lucky.



Are both head gaskets leaking? That seems highly improbable unless both heads were removed recently.
 

·
Registered
Joined
·
161 Posts
I've heard the heads can be removed with the engine in the bike but I think it would be much easier to pull the engine, especially on the Interstate. There's lots of things in the way that would no longer be a problem with the engine out.
It wouldn't be.



Folks have done in-bike head gasket replacement, myself included. Ever wonder why the Honda used a bolt instead of a stud for the front engine mounts that attach to the heads?



With the side panels and tank removed there isn't anything in the way. You could probably leave the radiator alone (though it needs to be drained.)



He's got 2-3 days to wait for parts so that's more than enough time to get everything prepped. Hopefully there is a garage or carport he can use but if there isn't a few big rubber bands and some trash bags would be my solution for covering the engine up.



This is entirely feasible and the ONLY unusual tool he'll really need is a torque wrench. (As someone else mentioned.)



Don't talk him out of having a great adventure to look back on.
 

·
Registered
Joined
·
4,035 Posts
Good luck on your HG replacement!



I like the idea of poping the head(s) off using the rope in the cylinder!



I haven't seen mentioned the little plug in each cylinder to drain the collant. Might be a good idea to get them drained.



Pics REQUIRED! please
 

·
Premium Member
Joined
·
2,510 Posts
Ever wonder why the Honda used a bolt instead of a stud for the front engine mounts that attach to the heads?



The GL does use a stud here, and that's the problem. If this stud is not removed from the head then lots of things need to be removed before the head can be pulled - fairing, fairing mount, engine hanger, radiator, fan, and fan shroud. If all that is to be done, it's not much more effort to drop the engine and then have easy access to everything.



It should be much less work to simply remove the stud from the head using the double-nut or a similar method and would probably be worth trying.



If simply re-torquing the head does not correct the problem then there is not much more that can be done without replacing the gasket. I'm not trying to talk him out of it at all, but just caution that it can be a little more work than may be initially obvious and to prepare accordingly.
 

·
Registered
Joined
·
40 Posts
Discussion Starter · #10 ·
I will certainly try to re-torque the head bolts/studs, I should be so lucky.



The oil seems to be free from any coolant contamination, and the overflow tank has nothing but coolant in it so I may be lucky or it may be something else.



Looking in the right hand side sparkplug hole I can see beads of coolant on the cylinder face so it would appear that both heads are leaking.



Will tackle this job tommorow afternoon and see what I find when I get some parts removed.





Pretty sure I can borrow a torque wrench from a neighbor. Definaltly prefer to have that when working with aluminum.



My GL does have the stud that DaveF mentioned, looks like it could create an problem but its mechanincal so can be solved.





Perhaps get some pics up tommorow, I am kinda beat right now.



Once I know what I need,I will call the closest Honda dealer to order. I will at least then find out about price and how long it will take to arrive.



Will keep you all posted.
 

·
Premium Member
Joined
·
2,510 Posts
Is it just one head gasket, or is it both? It seems extremely unlikely that both head gaskets would have failed in the same way, especially at the same time.



Are there other symptoms that would indicate a coolant leak into the combustion chamber? White smoke? Bubbles in the radiator? A few beads of moisture may not be indicative of an actual problem. This could just be condensation.



If you can borrow a radiator pressure test that may help confirm the gasket is indeed leaking. Remove the spark plug, pressurize the radiator, and check for a leak into the cylinder. Many discount auto parts stores have a tool loan program, and a radiator pressure tester is usually among the available tools.
 

·
Registered
Joined
·
4,035 Posts
Is it just one head gasket, or is it both? It seems extremely unlikely that both head gaskets would have failed in the same way, especially at the same time.



Are there other symptoms that would indicate a coolant leak into the combustion chamber? White smoke? Bubbles in the radiator? A few beads of moisture may not be indicative of an actual problem. This could just be condensation.



If you can borrow a radiator pressure test that may help confirm the gasket is indeed leaking. Remove the spark plug, pressurize the radiator, and check for a leak into the cylinder. Many discount auto parts stores have a tool loan program, and a radiator pressure tester is usually among the available tools.




I wonder if a compression test would help in this situation?



I like the idea of a coolant psi test1
 

·
Registered
Joined
·
8,423 Posts
If possible test the compression.You can do the head gaskets with the engine in place.No need to drop the engine.Just get as much out of the way as posted above.In this case get whatever head gaskets you can(And some decent high temp gasket sealer<Blue Hylomar is good)) and watch this,





http://www.youtube.com/watch?v=S1Bsc2zyihU&feature=mfu_in_order&list=UL



Don't forget to drain the two water jacket 10mm M6 bolts at the front of the cylinders and then tighten them back up( 6 to 9 ftlbs with some thread lock or RTV if not available)This releases the coolant form around the Cylinder jackets.



You will need a torque wrench among other tools but no special tools required.You may as well clean all the carbon off the heads and tops of the pistons etc.



Note:A blown head gasket is almost always a symptom,not a cause.Was the bike being run too warm e.g was their a problem with the water pump or cooling system.Did you notice the temp gauge running high?
 

·
Registered
Joined
·
2,618 Posts
I have replaced a head gasket (while replacing a valve) on my Interstate with the engine in and I have to say I would much rather do it that way than pulling the engine. I guess I'm not sure exactly what "stud" is referred to above, but I had everything removed in part of an afternoon with not that much effort. Sure, lot's of things have to be removed to get the head off, but why spend an extra hour or two removing and reinstalling the engine?



I agree with doing a compression test and of course Shep is right; what is the root cause if it is a blown gasket?



And whoever came up with the clothesline idea - BRILLIANT! As long as you don't have to put too much pressure on the piston to get the head to pop.



Good luck.



Fib
 

·
Registered
Joined
·
1,556 Posts
I also really like the cloths line idea! I wish I had thought of that a few weeks ago. It would have been much easier than what I did!

While the head is off make sure to clean the water jacket around the cylinder.

Mine were filled with crud and took a good bit of time to get them clean.

Engine or engine out I have no idea because mine is a CX and engine in was easy.
 

·
Registered
Joined
·
5,563 Posts
what if there is washing on the clothes line,is that ok?iv never took cloths off a clothes line,or put then on for that matter.





great idea
 

·
Premium Member
Joined
·
2,510 Posts
I have replaced a head gasket (while replacing a valve) on my Interstate with the engine in and I have to say I would much rather do it that way than pulling the engine...I had everything removed in part of an afternoon with not that much effort...



I confess I've never pulled a GL head with the engine in the bike. Your input is very valuable because you have done so. If it's really not that much effort, then this would seem the better way to go.



But first, has it been determined for sure that the head gasket(s) have failed?
 

·
Registered
Joined
·
3,999 Posts
I used to use a piece of rope to lock up chainsaw and bush saw engines to remove the flywheel. I would not recommend anyone trying to lock a CX engine using a rope though as it has valves and if it were not on the compression stroke it could bend a valve and the amount of torque needed to remove the flywheel may be too great.



The valves are all closed when removing a head so it should work pretty good for that though.
 

·
Registered
Joined
·
802 Posts
I used a compression gauge hose that has the quick disconnect on it and shop air from the compressor to pop a cylinder head off an engine once.

Of course the valves must be closed, and a shot of oil would help to seal the rings if necessary. One time a fellow mechanic told me he used a grease gun that he modified so it could thread into the spark plug hole, sure it pumped the cylinder full of grease but it definitely pushed the head up, in this case there were a lot of rusty head studs instead of bolts.

I used the grease trick myself for many years to replace the pilot bushings in crankshafts, fill it up with grease and then use the alignment tool pilot end into the bushing and hit it with a hammer, refill with grease until the hydraulic pressure pops the bushing out.
 

·
Registered
Joined
·
191 Posts
as for the cause of the headgaskets going bad, they are not meant to last forever, they do wear out and go bad. ALWAYS replace both gaskets, it is not worth it to tear it all apart do one side and then find out the other side was the bad one or that they both went bad. when you get them off you can visually check the heads for cracks, check to see why the gasket failed by looking for wear marks or blowouts in the gasket itself or wear marks on the engine block, also look for white spots on the valves or pistons and spark plugs. I dont know about motorcycles so much but when head gaskets go bad on cars you should get them resurfaced and have the machine shop check for cracks as well...just to be safe
 
1 - 20 of 70 Posts
Top