Stethoscope and borescope

I know that there's no substitution for tearing down an engine to inspect and measure. Riding season is pretty much over for a few months and I thought my commando was sounding noisy towards the end of the summer. I'm going to pull the timing cover and put on a new timing chain. and inspect the sprockets and stuff. I'm going to replace the early metal tensioner with the rubberized version too. My bike runs so well when I'm on the throttle and only can sound noisy at idle, so I think the timing chain is loose and I'm hearing the valve springs pushing on the backside of the cam and the chain going slack and then tightening again. I think that's why I don't hear it when I'm on the gas, because the throttle keeps the timing chain taut so it's less pronounced...

I know I can pull the plugs and use the back wheel to roll the crank over to listen for the chain slop to happen when I get on the backside of a cam lobe and that's probably the best non invasive test. I was wondering if anyone uses a stethoscope to listen to their engine at different locations to try to determine where noises are coming from, or If anyone has pushed one of those bore scopes up into the crankcase to look at the cam lobes/follower contact area??

*I know I can check my valve gaps to guess about cam/follower wear by noting a significant change in gap size on any valve adjuster... I'm just curious if anyone has used a borescope to look at their cam/follower and if that's possible.... It would save me the time and effort of pulling everything apart every time I hear a click that I don't like...

I don't have answer for you, but I also just got a borescope, type that connects to a phone for less than $30. Will be having a look down plug holes to inspect cylinder walls for scuffs etc.
The scope gives a surprisingly good image and has two cameras, at 90 degrees to the other.

Tornado said:

I don't have answer for you, but I also just got a borescope, type that connects to a phone for less than $30. Will be having a look down plug holes to inspect cylinder walls for scuffs etc.
The scope gives a surprisingly good image and has two cameras, at 90 degrees to the other.

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thanks for the feedback... Given the nature of solid pushrod engines and the fact that the only way (I've found so far) to inspect a commando's cam and lifter contact area, is to pull the barrels, I would love to be able to occasionally take a look at the cam lobes/follower faces without doing a tear down. If no one has done it,.... then you know what that means..... I'll have to be the first to try...

o0norton0o said:

thanks for the feedback... Given the nature of solid pushrod engines and the fact that the only way (I've found so far) to inspect a commando's cam and lifter contact area, is to pull the barrels, I would love to be able to occasionally take a look at the cam lobes/follower faces without doing a tear down. If no one has done it,.... then you know what that means..... I'll have to be the first to try...

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So is it even possible to get near cams from the sump drain?

Tornado said:

So is it even possible to get near cams from the sump drain?

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I'm wondering that exact thing. I suppose it involves pulling out the spark plugs so there's no compression forces and manipulating a camera on a stalk while you play with the position of the crankshaft.... I just figure that I should ask if anyone has tried it and found it impossible or maybe tried it and succeeded.

A while back I had a follower's stellite pad delaminate while my bike was idling in the driveway before an intended ride. That noise left no doubt that the head and barrels were coming off. I shut it off, tore it down, and found the loose stellite pad still sitting in place on top of the cam lobe with no damage to the cam. My paranoia enabled me to get away with just fitting a new set of followers to the barrels. After that incident, I pay attention to the sound of my bike... Maybe a little too much.

I think the timing chain inspection and change isn't really much of a tear down, so I'm just going to plan on that since I want to upgrade the chain and tensioner, but I would love to be able to look at my cam when I hear noises that I don't like, since commando's are solid lifter engines without hydraulics or roller bearings, etc.... I'll report back if I have a result. I'm not in a hurry since it's kinda cold out.... I'm just doing my homework by asking here to get feedback before I actually make an attempt at the borescope camera going up the oil drain hole possibilities...

I bought a camera of AliExpress or temu it's got an 8mm flexi end and you twiddle a knob , side camera as well , not sure about commando sump plug either , I've never had it up the bottom !

What you can hear with a stethoscope, and how accurately you can narrow down the location of what you hear, is amazing. Definitely worth a try.

o0norton0o said:

I'm wondering that exact thing. I suppose it involves pulling out the spark plugs so there's no compression forces and manipulating a camera on a stalk while you play with the position of the crankshaft.... I just figure that I should ask if anyone has tried it and found it impossible or maybe tried it and succeeded.

A while back I had a follower's stellite pad delaminate while my bike was idling in the driveway before an intended ride. That noise left no doubt that the head and barrels were coming off. I shut it off, tore it down, and found the loose stellite pad still sitting in place on top of the cam lobe with no damage to the cam. My paranoia enabled me to get away with just fitting a new set of followers to the barrels. After that incident, I pay attention to the sound of my bike... Maybe a little too much.

I think the timing chain inspection and change isn't really much of a tear down, so I'm just going to plan on that since I want to upgrade the chain and tensioner, but I would love to be able to look at my cam when I hear noises that I don't like, since commando's are solid lifter engines without hydraulics or roller bearings, etc.... I'll report back if I have a result. I'm not in a hurry since it's kinda cold out.... I'm just doing my homework by asking here to get feedback before I actually make an attempt at the borescope camera going up the oil drain hole possibilities...

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I was not able to see the cam surfaces with a borescope in from the sump plug.

If I raced 3 times per year, I would disassemble the top end at least once, to check. When developing a motor, that happens anyway.