I blew a head gasket the other week. I replaced all the top end gaskets in the front cylinder. It ran fine the day I finished the repair. I put about 8 miles on it. Today I go out to take a ride and I hear a distinct tap coming from the front rocker cover. I can't believe this! Could it be a bad valve?

 

Not sure what year or model your bike is but after you replaced the gasket did you remember to adjust your valves and tighten the rocker arm? Probably just came loose on you.

I've never had the head off my sporty so I may not be accurate and not even sure if there is a rocker arm and tappet adjustments. But a tapping noise is usually a loose tappet.

 

It is a 99 custom with a 1200 conversion. I did not take the rocker arms off. But I did have to loosen the rocker arm bolts. I did not do anythig with the tappets either. It was a simple gasket replacement. The book said nothing about adjusting the valves. I will have to look at my book some more and see what it says.

 

My book does not say anything about adjusting the valves! I did not mess with them at all. I guess I will have to pull the top rocker cover off and check the torque on the bolts. BUMMER!

 

Unless they put adjustable push rods in when they did the conversion, there is no adjustment. Did you put the same thickness gasket in that they did when they did the conversion? To thick of a gasket and it would be sloppy and to thin of one and it would be to tight, with the possibility of valve / piston contact.

 

yes, I mean, to the best of my knowledge. I did not put a caliper on it but it appeared to be the same thickness, at least close enough to not matter. I actually posed that question to the mechanic I bought the gasket set from. He said unless it was a "big" difference it was no problem. And there was definitely no big difference. The other thing that is frustrating is that after the repair there was no tap at all. I'm not sure about the end of the ride. It could have been there and I just didn't hear it. But it is definitely there today.
John

 

Take the valve cover off and start the bike, look for a good flow of oil up the rods. Some thing could be plugged? Maybe the noise will be in plain sight.

If the coversion was upped to 10.5.1 compression and/or cams? Gasket thickness becomes very important. If it was fine then started tapping maybe a squirter got plugged after some use.

Good Luck

 

PS.
Crap could also be plugging the oil filter.

 

THANKS! I did not know I could start the bike witht the valve cover off. Will the oil be a continuous flow or will it squirt with each rotation? How long can I let the bike run with the valve cover off? The conversion was done before I bought the bike, so I don't know all the specifics. The notes I have just has a list of parts installed: Pistons & rings, valves, cylinders bored, ignition module,heads,ignition coil. That's all I know about the work done. I don't know if 'heads ' means there were new ones bought or work done to the stock heads.
The oil is pretty black. I am going to change it and the filter tomorrow and then pull the valve cover off and see what's up. Do I need to replace the gasket or can the existing/new one I put in saturday be re used? Or am I just better off to get a new one just because?
John

 

It will spatter a bit but not tooooo bad. Depends on how big of a mess you want to make. lol.
If the gasket is felt, change it. Maybe put some 20 - 50 synthetic oil in.