No Compression


Information and questions on GL1100 Goldwings (1980-1983)
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jbmorris2001
Posts: 12
Joined: Sat Oct 10, 2009 7:34 pm
Location: ft campbell, ky
Motorcycle: 1983 goldwing Interstate

No Compression

Postby jbmorris2001 » Sun Oct 11, 2009 9:06 am



Hi everyone
I just bought a 1983 goldwing, this is the second goldwing I have owned. The owner told me that this bike sat for 2 years but I'm starting to think that it sat for more then that. I have multi. problems but here is the one that has me worried the most right now.
When I first started worlking on the bike I started with a basic engine compression test. I have around 80 to 95 around the all but one cylnder. I had 53 on the number 2 cyclnder so I thought it was the normal ring problem so went ahead and pulled the valve covers, timing belt, and loosed the cams on both side then filled the cylneders with WD-40. Once my new timing belts came in I then drained the WD-40 off and then retimed the bike to TDC and then installed the new belts.
After all this I rechecked the compression and this is where it has me stumped now. The new compression is 90 to 105 on all cylenders but the number 2 is now below 10 so it will not register on the compression gage I have.
I know part of my problem is in the started as it does not want to turn over the engine at the right speed, and if under compression it just about stalls out, but have been told that that should be a simple get the bike to run and warm up the engine and change the oil and it should unstick the starter clutch.
But my question is could I have the timing 180 out as there is only T-1 for number 1 and 2 cylnder and the rest is off the cams. Could I have just bought a bike that I now have to completely rebuild the engine. Any ideas and help would be great.

Johnathon



User avatar
Cal-D
Posts: 32
Joined: Sun Aug 30, 2009 9:32 am
Location: Nova Scotia
Motorcycle: 2007 Stream Silver GL1800A

Re: No Compression

Postby Cal-D » Sun Oct 11, 2009 10:07 am

When you do any compression test the throttle should be wide open with all plugs removed. First, you need to do a dry and then wet compression test. Do the dry then put several squirts of engine oil in the cyl and roll it over a few times then check the compression again. This will tell you if the compression loss is due to rings or valves. If the compression comes up considerably then problem is rings, if there is little or no change then it is valves. Then a leak-down will confirm, put that cyl at TDC and pressurize the cyl to 90 psi (shop air) and see where the air is leaking. Into the crankcase (rings) into the exhaust (exhaust valve) into the breather (intake valve) radiator or external (head gasket)
With 10psi in one cyl, I would guess you have a valve related problem, either burnt valve, stuck valve (bent) or bad head gasket. A proper dry and wet compression test and a leak down test will tell which it is.

jbmorris2001
Posts: 12
Joined: Sat Oct 10, 2009 7:34 pm
Location: ft campbell, ky
Motorcycle: 1983 goldwing Interstate

Re: No Compression

Postby jbmorris2001 » Sun Oct 11, 2009 10:16 am

The dry test was the first I did and I had below 60 but, the wet test before the soak of the rings and all was around the same. The part that worries me is that after the soak my compression dropped to below 10. I have to wait on tools to do the next test.

Thanks
Johnathon

User avatar
Cal-D
Posts: 32
Joined: Sun Aug 30, 2009 9:32 am
Location: Nova Scotia
Motorcycle: 2007 Stream Silver GL1800A

Re: No Compression

Postby Cal-D » Sun Oct 11, 2009 10:48 am

Johnathon
You should not use WD40 for that, use engine oil. (10W30)
The other quick check would be to remove the valve covers and slowly roll the engine by hand and make sure that all valves tapits develop slack when the cyl reaches TDC. This will quickly show if there is a bent or sticking valve.

User avatar
Cal-D
Posts: 32
Joined: Sun Aug 30, 2009 9:32 am
Location: Nova Scotia
Motorcycle: 2007 Stream Silver GL1800A

Re: No Compression

Postby Cal-D » Mon Oct 12, 2009 1:06 pm

The reason the compression dropped, my guess would be that the WD40 loosened some carbon deposits in the cyl and you now have a piece of carbon stuck in the exhaust valve stopping it from fully seating. Remove the valve covers and spark plugs. Slowly roll the engine by hand and check that each tappit has slack when the piston reaches TDC on the compression stroke.

jbmorris2001
Posts: 12
Joined: Sat Oct 10, 2009 7:34 pm
Location: ft campbell, ky
Motorcycle: 1983 goldwing Interstate

Re: No Compression

Postby jbmorris2001 » Mon Oct 12, 2009 5:56 pm

Thanks for all the replies. I went out and got a leak down tester and have now got some of the compression back. Yes and no about the carbon thing, it turns out that it is trash from the carbs, that has got into the valves but I have got a seal to the point that I should be able to start the bike soon as I get the bike put back together. Now I just have to work on the starter problem. lol




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