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The cylinder has a steel liner so the aluminum has to be coming from the piston or crankcase. Gasoline in the crankcase would also point to a failed piston or rings. The rattle could be from a loose piston pin due to worn bore in the piston, worn groove on the piston causing the rings to be too loose, or cracked piston skirt causing the piston to shake in the bore, but I think it sounds more like a loose cam chain since it is more prominent at the front of the cylinder where the chain has slack but the chain is on the left side of the front cylinder and you are hearing this on the right. Is the noise level on the left any less or more?
You could remove the alternator cover to inspect the chain and guides and tensioner but the engine has to be removed to replace the chain and guides.
 

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Rod knock would not go away as the bike warms up and would only get louder with an increase in revs. Rod knock is typically at the Rod big end (crank) bearing. A small end (wrist pin) issue would still make noise and would transmit through the rod into the crank and sound similar but not as pronounced. A wrist pin and piston issue would have a dead blow sound to it because of the aluminum make-up of the piston.
A wrist pin working itself out would be a constant noise and with the long stroke associated with your bike you would likely be seeing white or bluish smoke at the exhaust.
After looking at the IPB (Illustrated Parts Breakdown) on your engine I notice that the cam drive is on the LEFT side of the front cylinder and that mostly eliminates the cam chain, tensioner and guides as the noise generator.
The other two things that are on the right side of the motor that are RPM/frequency affected are the compensator and the front balancer.
  • The compensator is BEHIND the front cylinder and likely isn't transmitting noise through the metal that high. The drive chain however rolls along the upper guide which bolts nearly directly under the cylinder to crank case mating surfaces.
  • The front balancer is located directly below the cylinder and has a bearing just below the cylinder to crank case mating surfaces.
These two areas can be inspected WITHOUT engine removal.
The balancer also has a chain drive and tensioner. This is a possible issue but seems unlikely due to the fact that you only here the noise at the front of the engine and not BOTH cylinders. But the tensioner location may have more of an effect on the front balancer due to its location nearest the front balancer. Also able to be inspected WITHOUT engine removal.
There may be posts in Vulcan Forums about balancer issues and compensator issues that have worn or damaged chains, guides, tensioners or, loose compensator components.
 

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For whatever reason the two post before my last did not appear before I submitted my last.
Have you done a leak down test on the front cylinder? If the rings are indeed gone then you will have substantial leak down.
You can also find a really nice and reasonably priced bore scope at Harbor Freight Tools and look inside your cylinder to see any abnormal marks and wear. I have one myself and I check cylinder bores in my 2001 GSXR every time I replace plugs or clean the air cleaner. It's at that age and mileage.
 

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Did your bike make this noise BEFORE you did all of the work to it? IF NOT, then one of those changes is likely the problem.
What effect was the ECU flash expected to have? With a change in ignition timing you may have set up an advanced timing issue. On the motorcycle emission placard there should be an rpm listing for timing advance rpm limit. If this is the same rpm where you are currently experiencing this pinging/detonation sound then I'd would have the ECU re-flashed to stock.
Also try a colder plug range to eliminate hot pre-ignition conditions. And again, look inside cylinder to see if there is heavy carbon buildup in the piston crown which can also cause pre-ignition and detonation.
 

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Discussion Starter · #25 ·
It was making the sound when I first test road it, I even asked the seller about it and he said it was a loose body panel, but I'd never ridden another Vulcan, so I had nothing to compare it to other than my Yamaha Roadstars, which do make a bit of normal mechanical noise. The ECU flash is Ivan's, it's the most widely used upgrade with 1700 owners, so I'd assume it's not the problem. It would be great if it was only the balancer. I'll have to check. BTW, does anyone make an after market service manual? The factory Kawi service manual isn't the greatest and for what ever reason Clymer does not make one.
 

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I have driven vn1700 for hundreds of thousands of miles (really), the hyvo style cam chain does not wear like the vn15/1600 roller chain did, the vn1700 tensioners don't need extenders and none are available.
Vn1500/1600 cam chains are 'hyvo' as well, not roller chain.
 

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Discussion Starter · #27 · (Edited)
Here's the oil report, It's the first time I've ever had one done, so I'm not fully up to speed with what everything means. Maybe you guys can help shed some light on it?
Font Material property Rectangle Parallel Screenshot
 

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Discussion Starter · #28 · (Edited)
I just performed a cold compression test and I'm getting 79 psi front and 75 psi rear. Factory Service Manual spec is 61-101 psi. So it's defintely down on compression, but not out of range.

Update: I squirted some oil in the cylinders and retested. With oil it's 95 psi front and 110 psi Rear. Also, after putting the bike back together, I started her up and it smoked, as expected with all that excess oil and fuel in the cylinders, but the surprise was it smelt like sulfur, not burnt oil. That said, I did use old oil from my Roadstar, which is Mobil 1 V-Twin 20w50, if that makes a difference.

Also, this is what the new spark plugs look like after only 225 miles:

Front Plug-
Gas Metal Audio equipment Auto part Still life photography

Automotive tire Gas Water Automotive wheel system Cone


Rear Plug -
Cloud Automotive tire Wood Gas Automotive wheel system

Cloud Automotive tire Flash photography Automotive exterior Bumper


FYI - The white scratches on the rear plug is likely from reinserting the plug without a proper spark plug socket to keep it steady. I took it out last night then put it back in before removing it again to take the photo today.
 

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That gap..... isn't it supposed to be around 1.0 - 1.1 mm??


I just performed a cold compression test and I'm getting 79 psi front and 75 psi rear. Factory Service Manual spec is 61-101 psi. So it's defintely down on compression, but not out of range.

Update: I squirted some oil in the cylinders and retested. With oil it's 95 psi front and 110 psi Rear. Also, after putting the bike back together, I started her up and it smoked, as expected with all that excess oil and fuel in the cylinders, but the surprise was it smelt like sulfur, not burnt oil. That said, I did use old oil from my Roadstar, which is Mobil 1 V-Twin 20w50, if that makes a difference.

Also, this is what the new spark plugs look like after only 225 miles:

Front Plug-
View attachment 252050
View attachment 252051

Rear Plug -
View attachment 252052
View attachment 252053

FYI - The white scratches on the rear plug is likely from reinserting the plug without a proper spark plug socket to keep it steady. I took it out last night then put it back in before removing it again to take the photo today.
 

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I agree with Piper. That gap appears to be REALLY wide. And the front plug looks like it may be carbon fouling from the electrode to the ceramic. That is excessive carbon without a doubt. Rich cold then very hot is what makes that black soot then a clean ceramic tip.
There still may be a carbon spot on the piston causing that detonation in the cylinder. That is what I believe is the cause of said noise.
 

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Whatever you do. Don't try and re gap an iridium plug ! I've never had one come out of the box that needed adjustment. It is worth a shot to replace them again before pulling the motor. You will need to change them anyway if you do decide to rebuild. I'm with Moto Medic here and think your problem will be detonation, better to be a plug than fuel injector as I surmised on your other thread.

Good luck !!

Dane
 

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Discussion Starter · #33 · (Edited)
I’ll definitely double check the plug gaps, that said, gapping iridium plugs is fine as long as you use the proper tool and are careful not put any stress on the electrode. As for the combo of carbon and hot running; I commute about 2 miles each way, often twice a day, so I’m sure that’s causing the carbon build up. Then when I take an actual ride it heats up and burns off. I’ve had similar issues on my other bikes for the same reason.

Based on the 110 psi from the rear cylinder wet test, there’s definitely carbon build up in the rear. Other than Sea Foam or Marvel Mystery Oil in the gas and ridding hard, or pulling the heads and physically cleaning them, what other options are there to remove carbon build up? What about pulling the plug and squirting a bunch of Sea Foam Deep Creep in the cylinder and letting it soak over night?

Fingers crossed it’s only detonation. 🤞
 

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That $99.00, 8.5mm inspection camera from Harbor Freight Tools is looking better all the time. To get a glimpse inside those cylinders would be worth the investment. And you would have really cool pictures to share with your forum friends!
 

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I have one similar to this. It works pretty good. Looking in heat exchangers, in walls, and lot of tight spaces. Used in side my 5.4 ford when it blew plug out and had to drill and re-tap it.
 

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Discussion Starter · #39 ·
I was thinking about a wireless scope Plumber. Thanks for the link. So how the hell did you get all those shavings out. Just looking at those pictures make me cringe; especially the second one where you got all the big pieces but still have that fine metal dust stuck to the wall. ouch
 

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That's what I was thinking ab out getting Plumber. Thanks for the link. So how the hell did you get all those shavings out of your cylinders. Those pictures make me cringe; especially the second one where you got all the big pieces bet still have that metal dust stuck to the wall.
Shop vac with adapters down to a rubber hose small enough to get down the plug hole. And compressed air. Just kept going back and forth till it was cleaned out. Thats where the scope came in handy. Did all 8 of them. Drilled, tapped and put in inserts and new plugs. Truck runs fine.
I bought several of the scopes till I found one that had good resolution at close distance. That where having Amazon prime came in, (free returns). Defiantly one with at least 5 mp. Wireless is ok but it lags a little.
I've found cracks in heat exchangers with it. Water leaks in walls. With just a 1/2" access hole.
 
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