Motorcycle engine repair?

Question

I have 83 yamaha virago, the motor knocks from the front head area, could it be out of time on that head or maybe something more serious like a bent valve or the whole head needs rebuilt. Also it wont stay running and I know very little about bike motors and a new bike owner.

Answer 1

I once bought a nighthawk that had a loud knock and it would not idle. The person that had the bike before me had let the bike sit. Because of a bad float valve, the cylinders filled up with gasoline. When they went to start it, the liquid gasoline would not compress like air. It hydrolocked and bent the piston rod.

Anything outside of dissassembly and inspection would be a guess. (service writers know this) Getting a concrete answer from anybody would be a leap of faith. If it is a bent component insde the motor, you are looking at a costly repair any way you go about it.

Perhaps they could narrow it down for you by using a stethescope designed to listen to motors (...or maybe by placing the tip of a long s***w driver at various points of the motor, bottom-top, and putting your ear against the handle migh help you determine what area the sound is really coming from)

It could be next to nothing or major motor. You may find a bad tappet or bent crank. You will have to visually inspect it to be sure.

Answer 2

only way its out of time is if the cam chain is stretched which is very unlikely.It uses a hyvo chain which is damb near unbrakeable. It might be a rod knock.A valve is more like a high pitch tap or tick or ping.If its a rod and since its so old its not worth putting money into unless you really want to keep this bike.But for the money spent on repair you could find another Virago and keep this one for parts. Also if its a valve you would be blowing smoke out the exhaust.  

Answer 3

hard to say without hearing it run myself,put an ad in your local paper for someone who knows somethng about bikes,maybe youll find someone to look at it for $20 or so

Answer 4

That is the sound of the WalletVac spooling up.  Dude, you don't even want to know what it costs to fix a rod knock.