Steve Saunders Goldwing Forums banner
Status
Not open for further replies.
1 - 12 of 12 Posts

·
Premium Member
Joined
·
12 Posts
Discussion Starter · #1 ·
imported post

Hi All, I have a new to me 86 GL1200 Aspencade and here is the story.

Purchased about a month ago and I have it running now.
Here is what I have done:

Repaired the Electrical system, Stator wiring upgrade, Ignition relay, and DeButcherd the tail wiring.

Replaced Damaged Exhaust system.

Tuneup- Plugs, Air Filter, Oil and Filter, Belts, replaced Coolant

Cleaned Carburaters, Were not bad at all

Balanced Carbs.


The bike starts instantly and idles smooth with little engine noise. Accelerates smoothly and if kept under 2500 it runs through the gears fine. if I run it higher than that it starts a regular knocking like someone raping on the inside of the engine with a hard plastic hammer, louder under acceleration, quieter when under light load. The bike will run up to at least 85 mph and I drove at 2800 for about an hour and other than the knock it was near perfect.

I have rechecked the cam timing and I think it is correct, the flywheel has 'T' '1' 'F' on it with dashes on either side of the letters/number which is not explained in the book as to which set of marks is TDC. I set the timing on the 'T' and the dots on the cam gears lined up with the casting marks on the covers and was very careful to put the pulse trigger with the 'F' to the front.

The plugs read excellent, tan with no deposits and light sooting on the base.

At this point it is running me ragged, it is not pinging that sounds like clattering or popcorn, it is regular to the RPM, louder under load, near quiet under coast.


HELP!!!!!
 

·
Premium Member
Joined
·
1,148 Posts
imported post

Hi Centaurious... Welcome to the greatest GW board on the planet..

I have an 86 Aspy which had the exact same problem.. A Honda mechanic told me the knocking noise was coming from the alternator drive shaft in the rear of the engine and that the engine will need to be pulled to replace it... Just for S__ts & giggles, I took the left cylinder head off bocause that's where I heard the knock the loudest. Inspection found very heavy carbon deposits on the piston heads, valve faces and stem backs, and the cylinder head domes. I then pulled the right side head off and found the exact same heavy carbon build up... After cleaning all the carboned surfaces, installing new head gaskets and changing the oil & filter, the bike runs very smooth and the nock is gone... Apparently, the compression was building up too high and causing detonation at high rpm, under a load... I did'nt have to pull the engine and saved some big bucks not purchasing the alternator shaft...

This is not to say you have the same problem, but it's worth looking into... My bike sat for quite a few years and the previous owner only road it in parades and short trips.. He was an elderly man and belonged to the Shriners.

Let us know about any diagnostics you perform, such as compression test, timing belt, crank, valve & ignition timing.. There really is no sure way of checking the connecting rod & crank bearings or the wrist pins without an engine pull and block split... Try the carbon inspection before spending any more time & money on a tear down you really don't need:clapper:... Good luck and keep us posted.... Renegade
 

·
Premium Member
Joined
·
12 Posts
Discussion Starter · #3 ·
imported post

Thanks! With the carbs and intakes off I looked at the backs of the intake valves and they had minimal carbon.

The compression was between 170 and 176 on all cylinders.

I used a long screwdriver to listen to the engine and the area of the alternator was louder than elsewhere so you may be right.

Thanks and any other ideas are welcome.
 

·
Premium Member
Joined
·
1,088 Posts
imported post

The alternator shaft is a known wear item. It doesn't happen very often, but I have heard of it happening before. If the noise stays the same when you pull the clutch in I'd say the alternator shaft is worth looking at.
 

·
Banned
Joined
·
596 Posts
imported post

Centaurious wrote:
Hi All, I have a new to me 86 GL1200 Aspencade and here is the story.

Purchased about a month ago and I have it running now.
Here is what I have done:

DeButcherd the tail wiring.




The plugs read excellent, tan with no deposits and light sooting on the base.

At this point it is running me ragged, it is not pinging that sounds like clattering or popcorn, it is regular to the RPM, louder under load, near quiet under coast.

Id have to lean towards what Renegade said. Carbon or something like that. Whatever is causing it has to be found and fixed also.

If that electrical system is correct, and carbs are "factory" the spark plugs will be near white. I went through all this when mine was new ( 3 months to a year after buying a 1986 new in 1989) and repaired the electrics and tuned the carbs to "perfect" and it made the most power and ran the coolest at white insulators.Not that they were white "deposits", there was simply nothing on them. The spark plugs in that enginewere not designed to run brown. Brown is too rich. The same "brown" that builds up on the spark plugs also builds up carbon deposits in the cylinders which ties in with what Renegade said. The spark plug just runshotter than the piston and head dome, so it appears cleaner (brown instead of black). Try dropping the exhaust manifolds and looking inside and up in the heads, might find them full of carbon. Carbon in the cylinders raises compression and creates hot spots that cause detonation. IF the ignition is weak or misfiring, the intake valves may not look bad, but the exhaust valves could load up. Easy to check.

Also try a "shaving count" from the oil filter. Take it out and disassemble it and look for metal bits. Might find steel shavings?:shock:
 

·
Premium Member
Joined
·
1,148 Posts
imported post

Good point Dave Campbell.. I forgot all about metal shavings in the oil filter. Oil enters the filter housing and surrounds the filter from the OUTSIDE, passes thru the element to the inside of the bolt and on into the engine.. CHEAP & quick way to find out if you have any internal damage to a rod or crank bearing...

Dave also has another good point.. Drop the exhaust mainfolds and look at the backs of the exhaust valves for carbon deposits... A dead giveaway is black sooty looking pipes.. Look down inside them. They should be burning clean with just a small amount of darkish gray build-up.. not black and sooty...
 

·
Banned
Joined
·
596 Posts
imported post

Or starter drive chain knocking? Also listen around the exhaust manifolds for leaks.

Yes, the cam belts are put on with both pulleys on the mark and "T1F" on T. But it has to be the right "T1F" which coincides with both cam marks aligning to the cases. Its obvious when you get it set right.

Liked the "debutchering the tail wiring" , good way to put a bad thing.:clapper:
 

·
Premium Member
Joined
·
12 Posts
Discussion Starter · #8 ·
imported post

The wiring for the taillights had been scotchlocked so much it looked like they were half cut about 8+ times each.

Pulled the exhaust and the valves were clean with a slight buildup on one valve about 1/8" by 3/8" in size.

Inside the pipes looked good with the buildup that was there when installed turning grey.

The bike will slow rev to 4500+ and back down with no knock or clatter cluch in or out.
A quick rev, 1/2 throttle or so will produce some mild knocking and fade out as the revs stabilize.


I ran the bike at 3250 to 3300 on the Interstate for about 3 miles, killed the engine and clutched in, coasted to a stop and checked the plugs and they looked fine with mild color. Not a true High speed plug check with new plugs but no signs of any problems.

The knock is only under load with steady revs making light to no noise (cruise to coasting). Starting out if I accelerate hard through 2nd from 1000 to 2800 it only appears after 2500, no noise below that.

Anyone know where the idle/lowspeed/main rpm points are with these carbs? I can't think of anything else it could be at this point. Rods would knock on deceleration, the alternator shaft I can't see as being so engine load and not rpm related, lifters would be the same.

Thanks for all the help so far.
 

·
Banned
Joined
·
596 Posts
imported post

Centaurious wrote:
Pulled the exhaust and the valves were clean with a slight buildup on one valve about 1/8" by 3/8" in size. Inside the pipes looked good with the buildup that was there when installed turning grey... coasted to a stop and checked the plugs and they looked fine with mild color.
The bike will slow rev to 4500+ and back down with no knock or clatter cluch in or out.
A quick rev, 1/2 throttle or so will produce some mild knocking and fade out as the revs stabilize.
The knock is only under load with steady revs making light to no noise (cruise to coasting). Starting out if I accelerate hard through 2nd from 1000 to 2800 it only appears after 2500, no noise below that.

Anyone know where the idle/lowspeed/main rpm points are with these carbs? I can't think of anything else it could be at this point. Rods would knock on deceleration, the alternator shaft I can't see as being so engine load and not rpm related, lifters would be the same.

Thanks for all the help so far.



1.) Plugs and valves read good. Grey is not a problem, but its still not optimum. Verify that its charging at > 14 volts on idle.

2.) Noise appears above 4500 when revved slowly, but above 2500 when accelerated hard. May be oil system problem.

a.) What weight oil are you using? We pray not above 10W-30 in winter? 20-50 can destroy the main bearings from cold start starvation.

b.) Bad oil pump, collapsed oil filter, pressure bypass stuck, or oil return system blocked. Theseare known in race carswhen they install high volume oil pumps and it pumps all the oil into the heads and it cant drain back fast enough or the high pressure collapses the filters.

c.) There are tiny oil restrictors in each head to the valvetrain that can clog easily if the sealant on the ends of the cams is slopped on. Can destroy a valvetrain.

3.) low/transfer/main are around200 - 1200 low to transfer transfer, transfer to main from that to possibly 1500 - 2000 RPM, main above. Not RPM points, they fade in and out. Check Keihins web site and you might find better info on that.

Try removing spark plugs and attaching a ratchet to the crank snout and rotating the crank, might feel hard spots or hear loose things. There will be some knocking as directions are reversed because there are two chains inside, one in transmission and the other on the starter. Rotate it both directions, back and forth over short increments, but dont rotate the cam pulleys with a ratchet to avoid damaging a belt, this placed the entire engine load on one belt.
 

·
Premium Member
Joined
·
12 Posts
Discussion Starter · #11 ·
imported post

Charging system ok 13+ at idle, 14.4 while running.

4500 is the highest i've reved it so no idea if the knock will show up on it's own above there.

Drained out the India Ink and replaced with 10w40 for about 50miles, changed that to 20w50 castrol and no change in the knock. Background noises from engine slightly quieter with heavyer oil as to be expected. Using a NAPA Gold filter so that shouldnt be a problem. Sorry guys it's T-shirt weather here!

Rotated the engine through 3+ times after installing new belts, was feeling for any problems and everything felt good.

Next thing to try is replacing the plug wires and a different set of plugs. Will do a proper High speed reading and report.

Thanks
 

·
Banned
Joined
·
596 Posts
imported post

13+ volts on idle is bad. Must be 14+. Ignition will misfire.

Have one now that "taps" on the left side due to fuel going off in the exhaust manifold. Sounds for all the world like metal on metal noise. Down low in the stator area.
 
1 - 12 of 12 Posts
Status
Not open for further replies.
Top