Sudden noises.. Valve? Cct? Cam bearing?

Hello out there,

I'm a newbie here. I need help with sudden noise on my 1984 VF500F. It has 13,500, I bought it new and just got it running again. It ran great and quiet for 3 days straight (like new). Then yesterday I started it and it has this hissing/ticking noise out of nowhere. I checked for loose spark plugs and loose exhaust pipes and everything is tight. I'm thinking a cam might be running dry? or a broken valve spring? I don't want to run it, drop a valve and have to say goodbye after 31 years... Please don't laugh at my makeshift intake boots, still trying to find a new set... the bike did run like new for days. Of course I changed the oil and filter before going riding. I'm just hoping one of you have heard this before and know what it is. Any help is much appreciated.

http://youtu.be/qkbc17zDrAs http://youtu.be/qkbc17zDrAs

 

Is the sound more audible in the airbox? It sounds a LOT like a leak on the intake ... the frequency increases with the RPM.

Well .... a few other things I'd check to play things safe:

#1. Pull the valve covers off to double check that the cams are good. Make sure to remove the caps and actually inspect the journals on the cams for scoring. The older Honda V4 engines were notorious for soft cams and poor oil pressure to the head - although I don't think the 500 was affected by these like the 700/750+. I don't think this is the problem by the sound over the video, but better to be safe. (only do this if you're comfortable mechanically)

#2. Inspect your cam chain tensioners and guides. These are weak in the original V4s. (again, only if you're comfortable)

 

Thanks man, I sincerely appreciate your time and input. I actually took the airbox off and ran it until the carbs emptied, the sound was still there and sounds like it's coming from under the back valve cover on the right side. It's hard to tell but the video actually captures the sound pretty clearly, the sound actually sounds more pronounced on the video than live. It's strange because it was running and sounding perfectly and then it just started like this yesterday. I'll pull everything off again and check for scoring but other than cleaning carbs and changing oil, I'm not much of a mechanic. It might be the end of the road for my little ceptor.

 

No problem. Double check your intake boots ... it sounds like a vacuum leak the way it's hissing.

 

Time for a compression test, and don't start it again.

 

http://www.harborfreight.com/mechanics-stethoscope-69913.html

 

Problem solved, very easy solution. My makeshift intake boots were completely loose. The stock clamps were a bit too big and reached their clamping limit before tightening the boots, as a result one carb had popped free. All was solved with a new set of regular hose clamps! Runs like a champ again. Thanks very, VERY much for your help. I was seriously getting ready to pull the motor out and remove the heads if it would have been valve train related.

here's the "after" video...

https://youtu.be/-1S5LfMLw_c

 

Haha... awesome! Glad to hear it was something simple --- I guessed it! Leak on the intake boot.

 

You nailed it man. Thanks again.