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Discussion Starter · #1 ·
Hi All,

Just registered with your forum, I'm from the UK and currently own a 1980 CX500A and recently purchased a 1981 GL500 Silverwing Interstate which may need some work on the engine - water appears to be getting into the oil which over a 200 mile trip dropped on the dip stick by 1/3rd



I have just ordered a compression tester but as I've never used one before any advice would be very much appreciated.........



Regards



Longway
 

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Welcome in.



A compression tester is easy to use. Compression is best measured when the bike is warmed up.



Screw it in the spark plug hole, turn the kill switch on the bike and crank it over a few times and see what it's at.



There should be a button on the side of it to release the pressure and retest or move to the next one.





There are two options to your problem. One would be a blown headgasket. and the second would be the mechanical seal failed and the weep hole is plugged pushing coolant into the engine.
 

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IWWT this is interesting, so this is just a question why do ya hold throttle wide open when testing compression? If i remember correctly I never did that for a vehicle. Maybe it's a silly question figured I would ask, I plan on doing compression test over winter just to see where it's at.
 

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For a compression test, you also want to hold the throttle wide open during the cranking, and crank until the gage stops rising. This to to allow the maximum amount of air to enter the cylinders.



I doubt that this test will pinpoint your water in the oil problem. It is more likely to originate from a blocked weep hole in the water pump and a bad mechanical seal. But a compression test will give you a base line to judge things from. I think the normal compression is 171 lbs/sq in. Plus or minus 10%, with both cylinders also within 10% of the other one. A leak down test is better to judge the rings, valves, and head gasket if you find low compression. This involves pressurizing the cylinder at TDC and listening to the intake, exhaust, and radiator for air leaks.



Have you actually noted that the coolant level has dropped in the radiator? How much drop will also give a indication of the extant of the problem.



Welcome to the forum, there are several brethren from the "old country" here already.
 

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welcome in longway,im about 1200 miles south of you
 

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Discussion Starter · #8 ·
Thanks for the replys, I will take a look at the weep hole and check water level and let you know my findings



The bike has covered 81000 miles, I believe most of that covered in the US, it was imported to the UK in 1991 - what sort of mileage do you guys get out of these engines - I'm not sure about the service history for the engine but judging by the rest of the bike its been well looked after.



I am also a member of the cx-gl.org.uk forum and have heard about US based choppercharles and since I've just purchased a US Silverwing thought it would be a good idea to join
 

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Well we get basically infinity or till they stop running. If one takes care of an engine and replaces the wear parts I don't see why they cant run forever. I have about 65,000 on mine and it's doing fine.



Wear parts would be rubber, cam chain/tensioner and stator. After 30 years some of those rubber orings may not have had the best life. I don't even know how my mechanical seal didn't fail because it fell apart in my hand when the engine was refreshed. I also had a broken chain guide.



It doesn't take much to go through and engine on a weekend or slow week and give it a good once over.
 

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Discussion Starter · #10 ·
I managed to find some stiff wire and with a bit filing down it pushed up the weep hole and sure enough, when I ran the engine there is a steady trickle of coolant from there - looks like I'm taking the engine out




Although I've done a mechanical seal before on the CX, this time I'll have the fairing to remove as well, but first I'll do a Compression test and see if anything else needs doing while I'm at it
 

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no need to take the engine out there i s a method were you can leave it in here let me get the link for you its called the shep method



ok well i cant find the link



maybe some one has it saved and will pipe up soon
 

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Discussion Starter · #14 ·
Thanks Shep, The compression tester I've bought comes with 12mm adapter so should be OK



I see your from East Yorkshire, which ain't too far away from me near Leeds
 

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Thanks Shep, The compression tester I've bought comes with 12mm adapter so should be OK



I see your from East Yorkshire, which ain't too far away from me near Leeds


I used to know Leeds well.Played there loads in my old Rock band days.Great city.Great audiences




Up this way we have a few known owners in Bridlington,York,Grimsby.Met a couple but we tend to be a solitary breed




Maybe meet up sometime next year.
 

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Discussion Starter · #19 ·
Well, my compression tester arrived this morning so straight into the shed I went and here are the results



LH Cylinder 137psi Dry 169 oiled

RH Cylinder 134psi Dry 167 oiled
 
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