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1979 CX500 Custom
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Discussion Starter · #1 ·
79c finally on the road. Once I got it out the garage, I noticed a rattling coming from both side. It’s not there when idling. Thinking valves. Sounds like a lady with long nails typing very quickly.
 

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They are a somewhat "busy" engine .
make sure valves were done on the compression tdc..
And do the cam chain..

Also check oil level....and are u using a recommended wt or a lighter synth.??
 

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Discussion Starter · #4 ·
They are a somewhat "busy" engine .
make sure valves were done on the compression tdc..
And do the cam chain..

Also check oil level....and are u using a recommended wt or a lighter synth.??
Yes, I was wondering if I made a systematic error when doing the valves, since it is on both sides. I don't remember the noise being this bad before. I did wonder if the oil was overfilled, would overfilling cause this? Thanks. J
 

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Yes, I was wondering if I made a systematic error when doing the valves, since it is on both sides. I don't remember the noise being this bad before. I did wonder if the oil was overfilled, would overfilling cause this? Thanks. J
no it wouldnt. double check your valve tolerances, and make sure to adjust the cam chain when doing the left cylinder valve tolerances
 

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Yes, I was wondering if I made a systematic error when doing the valves, since it is on both sides. I don't remember the noise being this bad before. I did wonder if the oil was overfilled, would overfilling cause this? Thanks. J
I was thinking mayb too low a oil level/too thin a grade (below 10w30).....
More likely valve clearances/cam chain tension..
 

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Discussion Starter · #7 ·
I was thinking mayb too low a oil level/too thin a grade (below 10w30).....
More likely valve clearances/cam chain tension..
Right-o that makes sense
I was thinking mayb too low a oil level/too thin a grade (below 10w30).....
More likely valve clearances/cam chain tension..
Righto that makes sense. The only think with the oil I can think of is I put some seafoam in the oil a while back. I will change the oil and see what it sounds like before checking the valves and cam chain.
 

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Right-o that makes sense

Righto that makes sense. The only think with the oil I can think of is I put some seafoam in the oil a while back. I will change the oil and see what it sounds like before checking the valves and cam chain.
If it was me...do the valve &cam chain checks first....wont take long, as you mighy introduce a lil contamination anyway..
Run...see how it sounds...
Then drop the oil if its been diluted...how much seafoam did you add? Havent used the product myself...generally cause its hsrd to get here in Oz.
 

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Discussion Starter · #9 ·
If it was me...do the valve &cam chain checks first....wont take long, as you mighy introduce a lil contamination anyway..
Run...see how it sounds...
Then drop the oil if its been diluted...how much seafoam did you add? Havent used the product myself...generally cause its hsrd to get here in Oz.
Yes thanks. Your plan is better.
 

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1982 CX500C
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FWIW, I’d recommend only using cleaning additives (seafoam, marvel mystery oil, etc) just before an oil change. The contamination they’re meant to remove is going to drain into the sump and remain in the oil, so until it’s changed, it’s just going to continue circulating throughout the engine.

As to viscosity, I initially ran 10w30 the first couple of seasons I owned my 82, but I was having some issues with “clunky” shifts (adjusting the clutch made no difference), particularly from first to second. Last year I decided to try running 20w50 to see if I noticed any improvement and it began shifting much smoother.
 

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I'd be cautious about thicker oil's possible effect on the starter clutch.
Not that I’m trying to hijack this thread, but what about heavier oil concerns you regarding the starter clutch? So far I haven’t noticed any ill effects since the switch.

My owners manual shows 20w50 as acceptable for the temp range in this area.
 

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'84 CX650E that is evolving into a GL500
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Yeah, I'm not saying not to use it, just to be aware that if you have problems because of the 40 year old starter clutch springs you might have to change to lighter oil until you have the engine apart for something else and replace the springs.

I sometimes tend to think because I had a problem others will too and forget that the problem occurred in conditions most bikes won't be used in. In my case, I had run 10W30 or 10W40 in the winter for years and until the starter clutch springs started to go (along with numerous other issues that engine had) I had no problems with that. When I replaced the engine I had replaced the starter clutch springs in it and the next year I decided to try the Rotella T (now T4) (only available in 15W40) that everyone was talking about in it. When it started to get cold the starter clutch started to skip and one evening I couldn't get it started after it sat outside all day at -22c, even with the inline heater and under engine heater plugged in all day. On recommendation of several forum members I changed to T6 5W40 synthetic and the problem went away.
Now that I think about it you probably aren't likely to need to start your bike when it's that cold out (or even at the equivalent temp for having had the heaters on) so as long as your starter clutch is OK you'll probably never have an issue with 20W oil.

That said, my GoldWing (then with a GL1000 engine) didn't like the 15W Rotella either. Its starter clutch didn't mind but the main clutch became really grabby, even on hot days. I even tried replacing the friction plates and it did the same but it was OK when I changed back to 10W.
 

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Discussion Starter · #14 ·
Tried to look at the tensioner with the endoscope but had no idea what I was looking for. Loosened and tightened tensioner nut per some YouTube vid. Not sure this wasn’t always the case but now noticing the noise is during declaration and steady speed. Haven’t checked the valves yet but will. Noticed engine does not rev past mid revs but probably a separate issue with carbs.
 

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'84 CX650E that is evolving into a GL500
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Stop getting technical advice from "some YouTube vid" and read the section on what you need to do (in this case adjusting the camchain tension) in the FSM.
BTW: It is a bolt, not a nut and if done right it cannot make the engine louder.

The valve clearances must be checked when the piston on the side you are checking is at Top Dead Centre of the compression stroke. Note that in a 4 stroke cycle engine the piston reaches TDC twice per cycle, on the compression stroke and the exhaust stroke; At TDC Exhaust the valves are all open so the rockers should be pressing against the valve stems and there should be no clearance but at TDC compression the valves are all closed so the clearances can be checked and adjusted.
It is pretty common for people new to working on engines (& occasionally even people who have done it many times before) to check & adjust the clearances on the wrong stroke, resulting in very noisy valves (not to mention poor running because the valves don't open properly).
To determine whether you have done that set the engine to where the flywheel's TL mark lines up with the bumps in the timing port opening, then feel how much you can move the left hand cylinder's rockers by hand (NOTE that left and right of any vehicle are always relative to the operator's seat). Then turn the engine over while watching the marks and stop it the next time TL lines up with the bumps and see if you can move the rockers more or less than before. Ideally the rockers will not move by hand when it is at TDC exhaust and you will be able to move them slightly at TDC compression.
Check & adjust the clearances when TL is lined up on the stroke where you can move the rockers (or if they move at both TDC positions the stroke where you can move them more).
Repeat for TR and the right cylinder's valves.

As for determining camchain condition by looking at the adjuster, read this
 

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Discussion Starter · #16 ·
Stop getting technical advice from "some YouTube vid" and read the section on what you need to do (in this case adjusting the camchain tension) in the FSM.
BTW: It is a bolt, not a nut and if done right it cannot make the engine louder.

The valve clearances must be checked when the piston on the side you are checking is at Top Dead Centre of the compression stroke. Note that in a 4 stroke cycle engine the piston reaches TDC twice per cycle, on the compression stroke and the exhaust stroke; At TDC Exhaust the valves are all open so the rockers should be pressing against the valve stems and there should be no clearance but at TDC compression the valves are all closed so the clearances can be checked and adjusted.
It is pretty common for people new to working on engines (& occasionally even people who have done it many times before) to check & adjust the clearances on the wrong stroke, resulting in very noisy valves (not to mention poor running because the valves don't open properly).
To determine whether you have done that set the engine to where the flywheel's TL mark lines up with the bumps in the timing port opening, then feel how much you can move the left hand cylinder's rockers by hand (NOTE that left and right of any vehicle are always relative to the operator's seat). Then turn the engine over while watching the marks and stop it the next time TL lines up with the bumps and see if you can move the rockers more or less than before. Ideally the rockers will not move by hand when it is at TDC exhaust and you will be able to move them slightly at TDC compression.
Check & adjust the clearances when TL is lined up on the stroke where you can move the rockers (or if they move at both TDC positions the stroke where you can move them more).
Repeat for TR and the right cylinder's valves.

As for determining camchain condition by looking at the adjuster, read this
Bob- duly noted and appreciated. Thanks
 

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'84 CX650E that is evolving into a GL500
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Perhaps it isn't just the small amount of oil that is actually on the springs, caps & rollers but the film on the boss that the rollers have to grab or perhaps even the increased resistance to turning the engine when the oil is cold & thick.
All I know is that the starter clutch skipping was a serious problem with the 15W40 and disappeared almost completely after changing to lighter oil.
 

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Discussion Starter · #19 ·
Went through the proper procedure. Still seeing Jack with the endoscope. Dental mirror on its way. Did the valves again. Rhs way off so probably made a mistake last time. Still having carb problems; may just get some Murrays.
 
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