Ironhead Engine noise??

[IronMick]

Originally Posted by mandaltby

Im trying to figure out what it is. I dont see a loose bolt, it looks like its coming from engine area. It does it at lower idle speeds, the sound of a key hitting at the bottom of a cooking pot. Or a knuckle at the bottom of a pasta sauce pan. The bike is an 82 and was always noisy, IM just hoping that nothing is wrong, I hope to make till winter and a time for a rebuild. IU put in lucas plus the higher octane, engine has tons of power, however the noise still there.

Probably nothing. However, these should always be checked out, at least for your peace of mind.

Get a mechanics stethoscope and do some listening. Princess Auto or Harbor Freight [or wherever] - not an expensive item. With the steth in hand ask again here for specific directions.

[ryder rick]

Have you set the timing properly?
Try rotating the trigger very slightly counter clockwise, that will retard the timing and eliminate detonation or fix it.

Don't bother doing this unless you have fresh premium fuel in the tank. you should not run any thing but premium gas except possibly in the cold of winter

[mandaltby]

I did a bit of research on You tube and found similar sounds in cars that had a bent rod in engine. I was wondering how long my engine can last with a bent rod if that is what is it. Its a knocking sound, abit hollow sounding. As if you took a candle and hit it at the bottom of a cooking pot. I hear how Ironheads are bulletproof. If its just a knocking I can out up with it, I just hope that my engine is not going to crap out. I have not adjusted my tappets and was wondering if they are not adjusted right cant hat be a knocking sound. Its definitely not the gas or oil, I run about 100% octane, maybe more and change the oil religiously. I hear that its completely normal for Ironheads to make alot of noise. I guess that it could be a number of things, I just wanted to put it out there and find out, if people had Ironheads still "run forever", with knocking sounds, or is it a tell tale sign that shits gonna hit the fan. For all the experienced mechanics out there, a question would be what is the thing that usually goes first in an Ironhead engine, she's got about 22-25 thousand miles. Unless the people put a reverse drill on the spedo before I got it than Im not quite sure what she's got.
I guess another good question is should I take it easy on the engine?
I love giving it the Gar, but if I will end up walking, or driving my truck all the time I am willing to change my riding style till the winter and when I have time for a rebuild.
The sound is there right around 2500 rpm's when I go higher it disappears. And it only comes on when I hit the throttle, when its on plain idle the sound is not there. And its appears right when I apply the throttle. So if you are lets say trying to maintain a 55 mph speed, the sound is there annoying you.

[the cowboy way]

in my Ironhead (1980) motor dragbike once
I 1st heard it at start up 1st race of season
said to my crew chief we will get the stethascope out after this run
it was my only run that day
the motor locked up at the end of the track
a rod let go

I WOULD RIDE IT EASY

AND BUY A STETHASCOPE

[mandaltby]

wouldn't know what to do with a scope

[IronMick]

Originally Posted by mandaltby

wouldn't know what to do with a scope

Stick the two plugs in your ears then touch the probe to various parts of the engine. Virtually everything you listen to should sound like metal parts rotating; and all similar parts should sound about the same.

Start on the right side and listen at each of the rocker arm shaft end screws. Then listen at the top, middle and bottom of each pushrod. Then [thru the cover] at each of the 4 cams and at the generator idler and drive gears. You will notice the gen gears are really noisey!

On the left side start again at the top and listen on each side of the acorn nuts, at the cylinder head just below the spark plugs, in the middle of each cylinder, and at the bottom of each cylinder.

If you want to hear the really noisiest part put the probe on the generator end cap. You'll wonder how that thing stays together.

This is a procedure everyone should do with their bike, especially when it is running well. Then you know what it should sound like. These steths are not expensive. I think i paid like $25 at Princess Auto [Harbor Freight in the USA]. Much better than the traditional screwdriver or oil line.

[mandaltby]

I dropped by a shop and the guy told me that it sounds like the knock is coming from the bottom end. I think that the knock was there all along but it seems to be getting luder. I wanted to know what does it sound like if you tappets need adjusting. I guess I need to get a stethoscope and isolate the problem. If it is a bearing in the bottom end how much time can I expect to get out of the engine before she takes a crap? I hear so much on the topic, come people say that it will run forever, some say the rod can bust out the side of the case.

[mandaltby]

hey mick I did that with and I think that the noise seems to be coming from the front right rocker arm. On the right side of the bike towards the front wheel, the first cylinder. Hmmm. I listened all around the bike and it seems that is the problem. What does that mean. Can that be fixed by taking the rocker arm out without taking the rocker cover off. Or is taking the rocker cover not as big a deal as it seems.
Does that make sense can a rocker arm make that type of knocking sound?
Im looking at the manual and see that the valve is right there, could it be that?
any thoughts?
The guy at the shop told me that he thought its the lower end, but I listened pretty darn closely and could not hear anything from there.

[IronMick]

Removing the front rocker cover is not a big deal. Have a new gasket ready before you begin. Should have a factory manual in hand.

Get stuff out of the way - fuel tank, ignition coil, whatever. Remove the pushrods and the oil line. Then the cover.

However, before any of that check the pushrod adjustment; and wait for other responses here on the forum. There may be better ideas.

[mandaltby]

My buddy told me to perhaps try the simple stuff first like going back to the Harley Oil. I found that Valvoline makes a 60 wt racing oil, so I tried it. I bought a case, I dont think its that, but the noises were not there when I used the Harley oil. He said than adjust the tappets. What does it sound like if the tappets are not adjusted right?