2019 Honda Rebel 300 knocking...

Joined
Oct 7, 2012
Messages
5,365
Location
Staten Island, NY
So apparently I work on motorcycles now
...beats getting hit by them I guess :oops:

Neighbors kid bought a '19 Rebel 300 (ABS) brand new about two years back
Apparently it's a glorified scooter dressed up to look like a real motorcycle?
I don't know the profile of bikes and riders, I just swing the wrenches🔧
Said kid decided to do standard stuff of sticking lights and this and that on it, nothing wrong with that I suppose
Then the set about changing the oil, that's where the trouble started
It's two years old with 650 miles on it, so not exactly heavy use
He did the oil change, rounded the drain plug, somehow changed the filter, used oil of indeterminate type (he threw away the bottle)
Now it's got a tick/knock at idle
Now I don't know too much about bike engines, but by any engine standards it didn't sound good
Kinda rod knocky

It goes to neighbor across the street who's an avid rider with multiple sport bikes, apparently he "adjusts the chain"

No difference

I inquire about why I don't see him on it much anymore, I thought maybe he got bored with it?

He tells me the whole story, I say bring it up the block to my house, no guarantees, you may have already done irreparable damage

I've never worked on a bike before, but I thought being a small Honda it can't be that far off a pressure washer or lawn mower?

When in doubt, OEM parts is my motto, so I ordered up some service items from Babbitts online

Screenshot_20210731-104233.png


Plus the NGK plug it calls for in the owners manual, thought I'd treat it

I drain the oil, it looks reasonably new and clean, level seems right, the problem was a Fram filter, and a extra unnecessary O-Ring I found in the oil filter housing

PXL_20210731_005134682.jpg


There was also light metallic streaking around in some places (think draining a break in fill)

Cleaned it all out, new filter and gasket, new drain plug and crush washer, 1.5qt of the Honda GN4 10w30 as per the manual

Cranked it up and the noise disappeared 👍

Here's how it sounded when it arrived



Here's after work



So now I put it to those with more bike knowledge

What was that noise?

It had a correct amount of an oil in it?

It had a filter?

Is this a wet or dry clutch?

What in that engine could possibly get that upset about the wrong oil?

I'm buttoning it up today, he's over the moon that he's not gonna be in for an engine on a bike he paid $5k for new two years ago

I told him he can do all the lights and stickers he wants, leave the mechanicals to me 🤣
 
It's a motorcycle, NOT a scooter. You have no business working on it.
Well I did a **** better job than the last two people who worked on it

I think that statement is more of a joke "it's a 300, it's barely a bike"

But I'm not into bike culture, forgive my ignorance

I was told it'd look like a Vespa with me on it, luckily it's owner is shorter and smaller build
 
It’s a water cooled single, top speed is probably around 85.

It isn’t a scooter.

where was the extra o-ring? That would be my guess for the issue unless he filled it up with something other than motor oil.

It is a shared sump wet clutch.
 
300cc? ya, that's a glorified scooter.
Dangerous in fast moving traffic.
NYC, so not really extended high speed operation
If it can do highway speed (55), it's enough
It moves out, but then it's rider is 120lbs soaking wet with a helmet
I'd probably blunt the performance significantly :confused:
 
It’s a water cooled single, top speed is probably around 85.

It isn’t a scooter.

where was the extra o-ring? That would be my guess for the issue unless he filled it up with something other than motor oil.

It is a shared sump wet clutch.
I assume the extra o ring was included with the Fram filter, and he assumed you used it

It was just laying in there with the filter

Now I'm trying to figure what that noise was

I assume the clutch wouldn't like an off the shelf 5w30 meant for cars?

I don't know what he used, but I'd guess something readily accessable and cheap, so a PCMO of 5/10w-30?

Unless he bought Mobil 1 Racing 4T 10w-40, solely because there's a picture of a motorcycle on the bottle?

All purely speculative

I'll probably have it back in a few weeks to drain and fill the oil again, just to flush out whatever was in there
 
What was that noise?

To troubleshoot an internal noise the first step is to establish the
rate at which it occurs... is the noise in time with the camshaft or
crankshaft??? camshafts rotate 1/2 the speed of the crankshaft...
possible source of camshaft speed noises are shim and bucket
clearances... loose cam bearing blocks... broken valve springs...
possible source of crankshaft speed noises are a scuffed piston...
stuck piston ring... rod bearings...

To pin point the exact location of the noise hold a long tip screw driver or a
length of garden hose up to your ear and probe the suspected area...

What in that engine could possibly get that upset about the wrong oil?

No such thing as wrong oil because the only thing that will upset a motorcycle engine is no oil...

Screw driver trick...
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Starts cleanly after an air filter, plug, oil/filter change
I imagine it'll get even better as it's ridden more, and topped off with gas from this year
Deleted all the crap wiring he had for stick on lights, that's his problem not mine
There's a place in hell for the screws and nut serts used to connect the battery cables, too short what a PITA
Gotta go see other neighbor guy for missing side cover
Tires were both low :oops:
Aired up to spec
That's not terrifying at highway speed 😬

Now it waits for pickup
PXL_20210731_194200882.jpg


He knows he screwed up bad, and there's no guarantee this engine doesn't have damage that'll shorten it's life

He now knows to start with what the owners manual says, or ask me, or his dad, or literally anyone else

I'm actually charging for work these days, been getting tired of doing things at cost

I'll probably have it back in a week or two to drain and fill the oil again, I'll inspect for glitter or chunks with a clean pan

He never rides too far from home, and he's got a car for daily use, so if it does bite the dust, he can just stare at it and wait for a tow
 
Since the noise stopped with the oil change its a really tough call. the biggest issues I have seen are bad/worn valve adjustments or cam chain tensioner stuck. The chain slapping sounds like a knock and of course the valves are ticking, but I have never seen fresh oil solve either of these.
 
Your first video is marked private. It sounds pretty normal to me in the other two.

Last Honda MC owners manual I read said to avoid anything marked "energy conserving" but not much else on the subject of oil.

I doubt PCMO would cause it to knock unless maybe he put 0/16 or something super thin in it... wonder if the filter was correct for application? Maybe under pressure the extra o ring was somehow cutting off oil flow....
 
Was there any metal debris caught in the old filter down between the pleats? That's a good place to look for indications of any major engine wear issues.
 
... wonder if the filter was correct for application? Maybe under pressure the extra o ring was somehow cutting off oil flow....
That would be my guess too. Who knows what that extra O-ring was doing. He's lucky it didn't get pushed down inside the oiling system, which wouldn't be good.
 
Was there any metal debris caught in the old filter down between the pleats? That's a good place to look for indications of any major engine wear issues.
Nothing.

The oil that draining was far from glitter, just the faint streak of a different color, what I'd expect from the first drain of a factor fill engine

I should've used a clean pan and took better pics, but I guess that won't put the bearing material back in now will it 🤷‍♂️

I'll pay more attention to detail when I do another change in a week or two with it

Repost with better pics
 
If no real debris was found in the oil filter then I'd say the engine is OK.
 
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