Timing and engine noise with video

[Martin Brody]

Just wondering if anyone has had the timing light skip a few beats. The timing light seems like a pretty simple device but some flashes are skipped. wondering if thats my motor or the light? Anyone have this issue before. Also toward the end of the video you can hear the exhaust noise. Does this sound normal, could you tell if it was missing based on the sound? My next step will be to get a spark tester and go from there but here is video for now.


http://www.youtube.com/watch?v=h81wcx7piy8

 

[Don S]

Re: Timing and engine noise with video

What rpm is that idleing at, sounds like 500 or less. Should be up around 650.
My timing light skips on occasion too, so it does happen. Even with new wires, cap, plugs, etc.
But, it could also be that you need a tuneup, new wires etc.

 

[Howard Sterndrive]

Re: Timing and engine noise with video

hard to t/s noise on youtube, but I'd say it's more of a gimbal bearing noise than exhaust.

my timing light does that too.

 

[Martin Brody]

Re: Timing and engine noise with video

Thanks for the replies, I was afraid I was loosing spark. Will chalk it up to timing light. Tach in video shows it at 650 rpm. Hard to see maybe. Idle seems weak, funny thing happened the other day, I forgot I had 2 spark plugs out of my motor and started it up. It seemed like it ran just as strong with 4 cylinders as it does with 6. Thats why I am testing spark. Plugs on the fouled side too. I thought it was oil but now I think it was carbon fouling. I have a whole other post for that just thought I would shoot it out there.

I was thinking of doing a test, while the engine is running I would pull out a spark plug wire for a short time to see if the engine ran worse. If I pull one and the engine does not run any worse then thats a bad spark going to motor(or problem with that cylinder). Not sure if I can tell with a mercruiser but I can tell with my straight 6 in my truck. I was afraid about not grounding the wire but it would only be for a second or 2. Is this even worth trying?

I realize that it does have to compress the cylinder not being used and when I had the spark plugs out it did not have to compress it but that shouldnt take too much power away.

Compression on cyl's good.

 

[Philster]

Re: Timing and engine noise with video

It's right there at 600-650. If it were anything more than one cylinder as an issue (miss), I'd think she would not hold that RPM. Hard to hear, but once you start thinking you hear a miss, on a youtube video it'll sound like that even if it doesn't have one. Heck, certain cam timing sounds like a miss, and it is worse/trickier on an engine like that. She smooth out when revved???

Does it smell like some gas isn't being burned? Yeah, I'd check every plug/wire for ignition and would peak into every cylinder (if possible).

What's the rest of the ignition/distributor system like?