Still tapping....Spark Knock?


Information and questions on GL1200 Goldwings (1984-1987)
  • Sponsored Links
jtimgrant
Posts: 77
Joined: Sat May 25, 2013 7:24 am
Location: Greensboro NC.
Motorcycle: 1987 GL1200 Aspencade

Still tapping....Spark Knock?

Postby jtimgrant » Fri Nov 08, 2013 6:18 pm



I've had this tapping sound for some time and can't figure it out. It is non-existent while engine is cold or during warm-up. The sound is most noticeable when engine is at operating temp. It sounds as if it is only on one cylinder. It begins around 2600 rpm in overdrive and is most noticeable cruising 55 mph to 65 mph. When the throttle is closed the sound goes away. Open the throttle and it returns until you past 65 where it seems to go away. I pulled the plugs. All plugs color is exactly the same. The ground electrode is gray on all plugs but the insulator is pretty white with a touch of gray. This makes me think it's running lean and what I'm hearing is a spark knock. But if it is spark knocking it is only on one cylinder. The motor starts and runs great with no hesitation or other running problems. I know the float level is off approx .5 mm.

Any ideas? I'm beginning to think I need a Goldwing exorcisism. ;)



RATWING-86
Posts: 23
Joined: Tue Oct 01, 2013 10:15 am
Location: Deerfield, Virginia
Motorcycle: 1986 GL1200 ASPENCADE

Re: Still tapping....Spark Knock?

Postby RATWING-86 » Sat Nov 09, 2013 6:44 am

Sounds similar to my bike. Popping in the exhaust is caused by a bad air cutoff valve, the bike goes ultra lean on decel. I've got one ordered, so I've got a carburetor pull off planned today. On my machine not only does it pop, it surges as well at cruising speed off throttle. If you mash the throttle, it goes away. Does this scenario sound similar?
Motorcycles:
'81 Honda CBX 1050 (current and forever)
'03 Honda RC 51 1000 (current and forever)
'75 CB 750 K3 (for sale) good running bike
'86 Honda Gold Wing Aspencade, (the Ratwing)
too many more to list..................

jtimgrant
Posts: 77
Joined: Sat May 25, 2013 7:24 am
Location: Greensboro NC.
Motorcycle: 1987 GL1200 Aspencade

Re: Still tapping....Spark Knock?

Postby jtimgrant » Sat Nov 09, 2013 9:47 am

RATWING-86 wrote:Sounds similar to my bike. Popping in the exhaust is caused by a bad air cutoff valve, the bike goes ultra lean on decel. I've got one ordered, so I've got a carburetor pull off planned today. On my machine not only does it pop, it surges as well at cruising speed off throttle. If you mash the throttle, it goes away. Does this scenario sound similar?


Hi Ratwing. No, not popping. I did have that early on in the restoration. I rebuilt the carbs and replaced the cutoff valve. This is a sound something like a piston wrist pin knocking that is only heard at operating temp and at cruising speed in overdrive. It is baffling. All I'm doing now is guessing as to what is causing it. Right now I'm looking at a detonation due to a lean air/fuel mixture on one cylinder even though it doesn't sound exactly like a spark knock ping and the bike runs perfectly. It sounds more mechanical. One motorcycle mechanic friend said he thinks it's something in the transmission since its only heard in overdrive. I'm going to check the carb intakes for leaks again today in hopes of finding one of the intake orings leaking.

Thanks for replying.

t

RATWING-86
Posts: 23
Joined: Tue Oct 01, 2013 10:15 am
Location: Deerfield, Virginia
Motorcycle: 1986 GL1200 ASPENCADE

Re: Still tapping....Spark Knock?

Postby RATWING-86 » Sun Nov 10, 2013 7:04 am

I do have a slight tapping that I believe is a valve lifter. It's much better now after I followed the advice of another member, I added 8 oz of automatic transmission fluid to my oil. My bike sat for over 10 years, there's got to be a ton of sludge in it. I figure I'll run the ATF for 1500 miles, change oil and filter, then do it again a couple of more times.
Motorcycles:
'81 Honda CBX 1050 (current and forever)
'03 Honda RC 51 1000 (current and forever)
'75 CB 750 K3 (for sale) good running bike
'86 Honda Gold Wing Aspencade, (the Ratwing)
too many more to list..................

hunter27h
Posts: 67
Joined: Tue Aug 25, 2009 5:49 am
Location: Woodbine, georgia
Motorcycle: 1 1985 Honda Goldwings ltd trike
1989 GL1500
1991 GL1500 SE

Re: Still tapping....Spark Knock?

Postby hunter27h » Mon Nov 11, 2013 2:41 pm

if it is lifters, then add seafoam for a hundred or so miles, then change oil

jtimgrant
Posts: 77
Joined: Sat May 25, 2013 7:24 am
Location: Greensboro NC.
Motorcycle: 1987 GL1200 Aspencade

Re: Still tapping....Spark Knock?

Postby jtimgrant » Mon Nov 11, 2013 4:24 pm

hunter27h wrote:if it is lifters, then add seafoam for a hundred or so miles, then change oil


I don't think it's lifters since the noise is only at cruising speed. The motor is perfectly quiet at idle. The noise starts at 2600 rpms in overdrive and varies. It is not consistent. It is worse at 50mph than 60 mph. This morning it was non-existent the first 100 miles at any speed. Totally quiet. As the miles built up past 100 it became noticeable but still varied from noticeable to almost non-existent. It sounds like a wrist pin tapping but a wrist pin would be worse cold and as the rpm's rose. Also, a wrist pin would not be intermittent.

RATWING-86
Posts: 23
Joined: Tue Oct 01, 2013 10:15 am
Location: Deerfield, Virginia
Motorcycle: 1986 GL1200 ASPENCADE

Re: Still tapping....Spark Knock?

Postby RATWING-86 » Tue Nov 12, 2013 7:49 am

I'd try something in the oil first, either seafoam or ATF. It was the only thing that improved my noise, I do believe these lifters are dirt sensitive, and yes, my noise was prevalent at certain speeds, silent at others.
Motorcycles:
'81 Honda CBX 1050 (current and forever)
'03 Honda RC 51 1000 (current and forever)
'75 CB 750 K3 (for sale) good running bike
'86 Honda Gold Wing Aspencade, (the Ratwing)
too many more to list..................

hunter27h
Posts: 67
Joined: Tue Aug 25, 2009 5:49 am
Location: Woodbine, georgia
Motorcycle: 1 1985 Honda Goldwings ltd trike
1989 GL1500
1991 GL1500 SE

Re: Still tapping....Spark Knock?

Postby hunter27h » Tue Nov 12, 2013 9:52 am

I agree with Ratwing about the lifters, I get the tapping noise on my LTD at the strangest times, like at some point, it either looses the oil or something, but it occasionally happens, I hear it more at warmup, and not every time, and sometimes after running a while at idle, I don't hear it at road speeds, probably because of worn out ears, a can of seafoam is 10 bucks, loss of sleep is irreplaceable... ;)

jtimgrant
Posts: 77
Joined: Sat May 25, 2013 7:24 am
Location: Greensboro NC.
Motorcycle: 1987 GL1200 Aspencade

Re: Still tapping....Spark Knock?

Postby jtimgrant » Tue Nov 12, 2013 1:31 pm

hunter27h wrote:I agree with Ratwing about the lifters, I get the tapping noise on my LTD at the strangest times, like at some point, it either looses the oil or something, but it occasionally happens, I hear it more at warmup, and not every time, and sometimes after running a while at idle, I don't hear it at road speeds, probably because of worn out ears, a can of seafoam is 10 bucks, loss of sleep is irreplaceable... ;)


Sorry I forgot. I tried the seafoam a couple months ago for about 500 miles. It stayed the same.

Thanks

t

hunter27h
Posts: 67
Joined: Tue Aug 25, 2009 5:49 am
Location: Woodbine, georgia
Motorcycle: 1 1985 Honda Goldwings ltd trike
1989 GL1500
1991 GL1500 SE

Re: Still tapping....Spark Knock?

Postby hunter27h » Tue Nov 12, 2013 2:26 pm

Well my old ltd has about 54,000 miles and I still hear it occasionally for a few seconds, scared me the first time or two, but it is still chugging so I don't get concerned about it anymore, I do automatically check the oil pressure and temp though.
Good luck, maybe someone else has a better idea ;)




Return to “GL1200 Information & Questions”




Who is online

Users browsing this forum: No registered users and 1 guest