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Discussion Starter · #1 ·
Hello there,
This post is a continuation of a previous thread I started on an pre existing thread regarding noise.
Link below:

For "quick" reference:

Bike is a Honda GL500 Interstate 82' TI.
Service done fairly recently. Valve clearance on the spot. New cam chain and tensioner. New clutch discs.
Bike had been running beautifully as a daily runner for 2 months or so. Went for a few "speed" drives too. Not a single issue. Bike was actually amazing me constantly and despite the lack of fairings she was happy out getting to 140kmph. Never had the balls to go any further as wind in Ireland is quite a thing and the rear solid rim just doesn't help at all. Silly me. Anyways...

On the last 3 weeks or so the drama begins:

Whining noise coming from the lower half of the front end of the engine. Assumed my oil pump was a bit too slack or worn, noise didn't sound too worrying, just annoying. I decided I'd get to it at some point.
progressively the noise gets worse, but still, daily commuter regardless. Annoying but not worrying. Every morning I'd get to 100 happily through the streets of Limerick waking up everyone on the way to work.

3 days ago i noticed a sudden loss of power. At first I thought I ran out of fuel AGAIN (she drinks a lot) but when put on reserve same issue happened, 1st gear starts OK but after a few degrees of twist on the throttle there is no more power despite higher revs, kicking in the 2nd provides the same, 3rd does push the bike but at a much much much lower speed, high rpm, and noise that reassemble the whinning of a horse just too tired to keep on pulling crap.
Yesterday the high pitch noise got much worse, I could swear it was from the top half of the front engine. Every now and then there'd be a high-medium pitch thumping. The loss of power was brutal. Constant whinning, and the rattle and thumping you'd get from a loose dashboard x10.

so far assessed nothing is lose. Currently trying to take out the fan (I had a puller bolt, I had to move houses, the bolt must have decided to stay behind) so I can assess the tacho unit.

Spinning the engine using the crank shaft inspection hole brings no noise in neutral nor 1st. If I however spin counterclockwise I do hear high pitch noises. Not sure if normal, truth be told all I know about bikes is thanks to this poor thing.

Spun the engine with the kill switch on and the clutch switch hard wired out of curiosity. No weird noise on neutral nor on 1st.

Sick of it had the bike running for a few seconds without the radiator, hoping without the rad on the way I'd be able to discern what's going on. No weird noise either.

it seems to happen only when over certain revs and moving...is it the speedo unit? Some might ask, nope, spun the front wheel, she happy too.

Removed the tacho cable from the deceased tachometer (why was I so stupid to leave it on knowing the tachometer was dead...?) No difference. Cable is absolutely fine and spins happily when turning the engine but won't let you twist nor pull if engine is not moving (I want to think that means it isn't broken).

My theories in avoidance of even thinking of the possibility of serious damage inside the engine are so far are:

Combination of the following:

My oil pump chain is messed up
+
My tacho unit isn't happy either (I had a incident going over a speed bump too fast and a lot of parts suffered the consequences, my fork seals blew, my gauges died, and both my fenders had to be replaced, even blew the main fuse)
+
my valves are just covered on grime.
This is really possible as it is one of the few things I haven't done yet, and it took me a while to get my carbs adjusted to the pods and custom exhausts, after I gave up trying to fix the older carbs that had leaks EVERYWHERE.

So...fully aware that without seeing the vrumvrum is a bit hard to discern what it could be. The idea here is wild guesses, that hopefully I haven't had myself yet, and all together by trial and error we might just find what's ailing my fat-fe racer.

Tire Wheel Sky Cloud Fuel tank
 

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diagnosing a problem that starts off with a sound is beyond difficult on a forum. any chance you can get a quality recording, upload it to youtube and post it here?
 

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The bike in question is a GL500.

"...
For "quick" reference:

Bike is a Honda GL500 Interstate 82' TI. ..."
 

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Loss of speed (power?) while achieving higher rpms could be the clutch slipping (out of adjustment or worn out). Clutch might make whirring noise if slipping vigorously, and it’s in the front lower part of the engine where you believe the noise seems to originate? I’d look at the clutch cable for the desired play/slack next.
 

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1978 CX500 "The Grub", 1983 GL650I "Nimbus"
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Be aware that sound travels in strange ways inside these engines. Unless you used a stethoscope, a noise you think is at the front could easily be a failing camchain in the rear.
 
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Discussion Starter · #7 ·
diagnosing a problem that starts off with a sound is beyond difficult on a forum. any chance you can get a quality recording, upload it to youtube and post it here?
Will definitely do. Thank you!!

I'm trying to multiquote but I'm getting more and more useless with tech the older I get.

About that stator check, that's for a CDI engine, mine (thank the gods of speed) is TI. Much appreciated regardless, not a bad guess, and answering to that my stator, reg/rec and spark units are immaculate. Will check again but highly doubt it could cause this hassle.
Did notice the rear qheel tried to spin with the clutch engageg

Got the fan off. Discarded the possibility of it or the housing making noise. Spun the engine several times without any of it, the bloody noise will only come at higher revs. Will check tacho unit properly today as well as heading for the oil pump chain and god willing, my valves.
 

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Discussion Starter · #8 ·
Click on post by accident...

So continuing...

Did notice the rear wheel spinning on 1st even with the clutch engaged when spinning the engine from the crankshaft, so could my clutch cable not be tight enough? Will check today too.

My new hurtful truth avoiding train of thought is saying...OK, how about it your valves are just dirty, your oil pump too slack (anyone knows how tense it should be??), your valve clearance slightly off even though you left it perfect months ago, the already known to be noisy clutch is not quite happy at the moment, and the odd thumping noise you could only hear when driving at speed and could swear comes from the dashboard or right below does indeed come from the broken tacho itself and the tacho unit responding to it as opposed to something more serious?

All of this shall be done this weekend and hopefully that's that. Because truth be told I must figure this out. Bike culture in Ireland is next to 0, there isn't that many mechanics in the whole country, and last time I rang the one in Dublin, the other dude in Cork, and went to one in Limerick hoping they'd feel like changing my fork seals and balancing my front wheel they straight up refused because "bike is too old, I don't know how to do those forks, and i don't want to damage the wheel taking out the axle".
Like...honestly? I thought it'd be harder the way he said it. Had to do it myself in my back yard. Didn't die trying. Just a cut on my finger from a jumpy spring. Once done I realised how Honda back then made sure this things could be done by the owner of the bike.

And I got too much effort and emotional attachment besides the thousands ive poor into this bastard and will NEVER see back to just sell it off or scrap it. Not happening. Not an option. She is a keeper.

Will keep posted. Thanks again for all the help fellas. This forum is just worth the weight of its servers and participants on gold.
 

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Be aware that sound travels in strange ways inside these engines. Unless you used a stethoscope, a noise you think is at the front could easily be a failing camchain in the rear.
Old school guy taught me to use a screwdriver or like object against the case w/ your ear almost against the end of it while holding it not too firmly. It has actually helped me narrow down a noise.
 
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Did notice the rear wheel spinning on 1st even with the clutch engaged when spinning the engine from the crankshaft, so could my clutch cable not be tight enough? Will check today too.

I'm assuming you mean with the wheel off the ground? There is always -some- friction even with the clutch pulled all the way in so the wheel turning off the ground is normal.
 
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Friction and oil drag through the gears means they'll usually spin the rear wheel on the centrestand in neutral.
 

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The bike in question is a GL500.

"...
For "quick" reference:

Bike is a Honda GL500 Interstate 82' TI. ..."
Sorry missed that. these 60+ hour weeks are scrambling my brain. One more week till "peak" is "officially" over!
 

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Discussion Starter · #13 ·
Trying to quote those two comments about the wheel spinning...yes, I was expecting it to spin off the ground when on neutral, I knew that was OK. Silly me (yet, again) at first I had it on the side stand on 1st and clutch engaged and to my surprise and grief of my battered back I had to catch it mid fall. As much weight as I managed to remove out of her, she is still too heavy to mess with it like that. Now I know if the bike were on 1st it would shoot out but I wasn't expecting it to do so with the clutch completely engaged with a zip tie and only cranking by hand...so that's normal too then?
 

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Trying to quote those two comments about the wheel spinning...yes, I was expecting it to spin off the ground when on neutral, I knew that was OK. Silly me (yet, again) at first I had it on the side stand on 1st and clutch engaged and to my surprise and grief of my battered back I had to catch it mid fall. As much weight as I managed to remove out of her, she is still too heavy to mess with it like that. Now I know if the bike were on 1st it would shoot out but I wasn't expecting it to do so with the clutch completely engaged with a zip tie and only cranking by hand...so that's normal too then?

When you say engaged that means that the clutch handle is out, at least to me. I'm guessing you mean the handle is pulled in and tied so that would be disengaged.

A bike should not move forward with the clutch pulled in like that but I've never turned mine over by hand with it in gear on the ground and with the clutch pulled. I know if it's in gear, clutch pulled and I use the starter the bike will not move forward.

There ought to be plenty of resistance if that tire is on the ground to allow the clutch to slip. I'm guessing something isn't right in your clutch or is adjusted so far out that the cable isn't pulling the clutch.
 

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I often get excessive clutch drag on a cold start. It goes away fairly quickly as the oil warms.
 

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The hop and clutch drag referenced by the 3 above happens to me on other bikes but never to the extent of moving the bike; I'll feel a little drag on that first engagement after starting a bike that's been sitting weeks or more.

As someone else pointed out, when you're driving in any gear and you give it throttle and your RPMs go up but you don't go faster you have to look at the clutch. That's the only point mechanically that slips...unless the drive shaft splines on the output shaft could somehow be stripped and slipping?

It would seem easy to take that front cover off to look at everything, especially since it was recently done I doubt it'd be much of a fight.

Whining and thumping can't be minor on any engine. I'd be looking inside. Your problems started after having certain work done; those are the points you should be looking at first.
 

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Google results for "thumping clutch" combined with a whining noise I would suspect there is no good news here.

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Discussion Starter · #20 ·
Sorry missed that. these 60+ hour weeks are scrambling my brain. One more week till "peak" is "officially" over!
And where are my manners? About the CDI testing method. Thanks all the same bro. Any help honestly is much appreciated.

And the other advice about the screw driver. Thanks too, will be trying that all over. Sounds like a good good trick.
 
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