Now what? No compression after replacing valve seals.
Moderators: CYBORG, Oldewing, robin1731, Forum Moderators
- John Schmidt
- Silver Member
- Posts: 726
- Joined: Sat Mar 02, 2013 2:28 pm
- Location: Winter Park, Florida
Now what? No compression after replacing valve seals.
What the sam hill is going on now, finished replacing all the valve stem seals and rolled the motor over to be certain nothing is hitting(it isn't). So installed the plugs and hit the starter with just a short bump first and it spun over like there were no plugs installed. WTH? Then tried holding the start button for a few seconds and it spins like there's no plugs in it. Got out my trusty compression tester and checked the right side without any plugs installed.....ZIP! Barely moved the needle so just to be certain the gauge is working I hit it with a short blast from the air hose and it registered fine at 90psi so nothing wrong with the gauge.
So before I start tearing into the motor & tearing my hair out, does anyone have a suggestion(s) as to where to turn next? And to make bad matters worse, I got an email this morning asking what's the best I can do re. a sale price....in cash.
So before I start tearing into the motor & tearing my hair out, does anyone have a suggestion(s) as to where to turn next? And to make bad matters worse, I got an email this morning asking what's the best I can do re. a sale price....in cash.
1984 GL1200 Standard, work in progress
1998 Valkyrie Tourer, my Honda Davidson
1998 Valkyrie Tourer, my Honda Davidson
- CYBORG
- Moderator
- Posts: 24552
- Joined: Mon Jan 14, 2008 12:52 pm
- Location: Muskegon mich
Re: Now what? No compression after replacing valve seals.
Seems to me that a valve is not sealing well, or they are way out of adjustment
1978 custom GL1000
1977 custom with 1200 engine
1985 gl1200
1977 custom with 1200 engine
1985 gl1200
- RB
- Honored Life Member
- Posts: 4268
- Joined: Sun Apr 29, 2007 7:26 am
- Location: AZ
Re: Now what? No compression after replacing valve seals.
LIKE 180 out???
98 1500 SE..
99 1500 SE SOLD
97 SE 1500 SOLD
83 SOLD
82 REBUILT sold!!!
81 DAILY RIDER sold her ((!
81 REBUILT SOLD!!!
81 REBUILT SOLD!!
80 REBUILT SOLD
79 IN BASKET PARTS FOR SALE
79 CLEANED UP AND SOLD
78 REBUILT SOLD
77 REBUILT SOLD
76 SOLD/PARTIAL REBUILD
76 REBUILT AND SOLD
75 REBUILT SOLD
75 REBUILT SOLD
75 REBUILD SOLD
FAIR WINDS,
RB
99 1500 SE SOLD
97 SE 1500 SOLD
83 SOLD
82 REBUILT sold!!!
81 DAILY RIDER sold her ((!
81 REBUILT SOLD!!!
81 REBUILT SOLD!!
80 REBUILT SOLD
79 IN BASKET PARTS FOR SALE
79 CLEANED UP AND SOLD
78 REBUILT SOLD
77 REBUILT SOLD
76 SOLD/PARTIAL REBUILD
76 REBUILT AND SOLD
75 REBUILT SOLD
75 REBUILT SOLD
75 REBUILD SOLD
FAIR WINDS,
RB
- John Schmidt
- Silver Member
- Posts: 726
- Joined: Sat Mar 02, 2013 2:28 pm
- Location: Winter Park, Florida
Re: Now what? No compression after replacing valve seals.
Re. valve not sealing....in every cylinder?!? I could see that happening in one, maybe two, cylinders. The 1200 valves aren't adjustable, hydraulics involved...similar to hydraulic lifters in a car.CYBORG wrote:Seems to me that a valve is not sealing well, or they are way out of adjustment
1984 GL1200 Standard, work in progress
1998 Valkyrie Tourer, my Honda Davidson
1998 Valkyrie Tourer, my Honda Davidson
- John Schmidt
- Silver Member
- Posts: 726
- Joined: Sat Mar 02, 2013 2:28 pm
- Location: Winter Park, Florida
Re: Now what? No compression after replacing valve seals.
How could that happen if you don't turn the motor over and the belts weren't off? I just used the rope trick in the cylinders and rocked the bike back/forth in 4th gear, just enough to compress the rope against the valves.RB wrote:LIKE 180 out???
It ran like a raped ape before, just smoked some upon start-up after sitting for a time. I'm wondering if the "hydraulic lash adjuster" have bled down while not installed.
1984 GL1200 Standard, work in progress
1998 Valkyrie Tourer, my Honda Davidson
1998 Valkyrie Tourer, my Honda Davidson
- CYBORG
- Moderator
- Posts: 24552
- Joined: Mon Jan 14, 2008 12:52 pm
- Location: Muskegon mich
Re: Now what? No compression after replacing valve seals.
I think you have hit on something. The lifters on the 1200 are not true hydraulic, like you see on a car of the USA design. Check the manual for the setup of the valve clearance. Probably air in the system. Verify by watching the movement of the rockers while turning over the engine.
1978 custom GL1000
1977 custom with 1200 engine
1985 gl1200
1977 custom with 1200 engine
1985 gl1200
- John Schmidt
- Silver Member
- Posts: 726
- Joined: Sat Mar 02, 2013 2:28 pm
- Location: Winter Park, Florida
Re: Now what? No compression after replacing valve seals.
New twist....went out this morning and with the plugs still out I bumped the starter, it sounded different. So, put the plugs in, hit the starter and away she went. I had run it on the starter a number of times last night before throwing in the towel for the day so maybe the system got refilled or whatever it does. Anyway, it now runs as before with one exception; I apparently damaged a gasket on the left side near the front behind the belt housing. It appears my new leak is in the area where the cam holder goes up against the back of the belt housing that bolts to the front of the head. The leak is quite extreme so guess I have another project soon as it cools off. Like I said earlier....WHAT NEXT?
1984 GL1200 Standard, work in progress
1998 Valkyrie Tourer, my Honda Davidson
1998 Valkyrie Tourer, my Honda Davidson
- CYBORG
- Moderator
- Posts: 24552
- Joined: Mon Jan 14, 2008 12:52 pm
- Location: Muskegon mich
Re: Now what? No compression after replacing valve seals.
Good to hear. If left to their own devices, they will self bleed off air, if its not to severe. Gaskets are easier, and straight forward.
1978 custom GL1000
1977 custom with 1200 engine
1985 gl1200
1977 custom with 1200 engine
1985 gl1200
-
- Titanium Member
- Posts: 342
- Joined: Fri Jun 12, 2015 8:11 pm
- Location: Bellingham wa.
Re: Now what? No compression after replacing valve seals.
What will happen with those hydraulic lash adjusters (HLA) is without the push back from the valve spring they will extend out when removed. Either just keep cranking the engine over or let them sit for awhile and they will compress. Or gently squeeze them in a vice to bleed the oil out before reinstalling. But with that method you will have lifter noise until the pump back up.
- John Schmidt
- Silver Member
- Posts: 726
- Joined: Sat Mar 02, 2013 2:28 pm
- Location: Winter Park, Florida
Re: Now what? No compression after replacing valve seals.
UPDATE: Next time(if there is one) I'll take a closer look at the oil seal at the front of the cam on the left side. I had pulled the bottom of the radiator out so I could remove the left half of the belt covers so I could inspect the seal behind the left timing pulley. The right side cam is held in place by the FI timing apparatus on the back of the head, I don't use it since I converted to carbs and mounted the timing pickups on the front so just removed the pickup mounted in there. I wanted to make sure the cam seal hadn't become dislodged, a quick check and all seemed OK so I buttoned in all up and started the bike. It ran great and suddenly oil started pouring out from the bottom of the left belt cover. #&*%#$@# I let everything cool down....including myself, pulled the left belt cover again and there it was; the seal was just dangling on the end of the cam. Everything was soaked with oil on that side so I began the removal of everything to enable a clean up. The belts were new but I replaced them again after the soaking, $14.99 ea. at O'Reilly's for a set of Gates. I happened to have the seal and gasket that goes behind the rear belt housing that bolts to the head so the last couple days have been spent cleaning up the mess, installing the seal and putting it all back together. Took 3 tries but got the timing marks spot on again. R&R the radiator is a veritable PITA but got it in eventually. Just a while ago I hit the starter again and let it run....no leaks this time. Just a lot of smelly smoke from burning off what had spilled onto the exhaust.
I'm not sure what caused that seal to become dislodged, but it did. I had taken the precaution of securing the rear end of the left cam when removing the cam holder to change the valve seals. The cam may have moved just enough to break it loose and I was in too big a hurry to button it all up after finishing the valve seals. Next time I'll actually poke my fingers in between the spokes on the pulley to make sure that oil seal is in place. Some lessons sure are time consuming....and expensive.
I'm not sure what caused that seal to become dislodged, but it did. I had taken the precaution of securing the rear end of the left cam when removing the cam holder to change the valve seals. The cam may have moved just enough to break it loose and I was in too big a hurry to button it all up after finishing the valve seals. Next time I'll actually poke my fingers in between the spokes on the pulley to make sure that oil seal is in place. Some lessons sure are time consuming....and expensive.
1984 GL1200 Standard, work in progress
1998 Valkyrie Tourer, my Honda Davidson
1998 Valkyrie Tourer, my Honda Davidson
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