Topic: 74 cb550 squealing/high pitch noise

[Jimsun]

Hey guys
The bike was running well. Everything was done. Rebult carbs and synched them. I also did the cam chain, timing and the valve gap. This is also done with new oil, oil filter and spar k plugs.

I went for a 2 hour ride and everything was fine.
Then when I stopped for coffee, I parked the bike and got off. I forgot to put the kick stand which caused the bike to fall. It was a soft drop because I was able to catch it and have it land softly to the ground.

On my way home, the bike wouldn't want to idle in neutral at 1.2k rpm. It would even die at 1.4-2k rpm range.
I also noticed that the exhaust is pumping out more smoke than normal.

Lastly, here's the noise idling at 2.4-3.6k rpm. I also noticed oil leaks on the left side fins.

Please give it time to upload
http://youtu.be/Ie15TUE7R-s

Also, how do i go abouts adjusting the rich/lean of the bike? Here's a picture of my #2 plug and #1 which contains some oil. Do i screw the adjuster clock wise for it to be more lean?

[Don R]

Don't panic, it might be a float sticking and a little oil and gas getting where it shouldin't be. I'd put it on the center stand, check the plugs and float levels, clean off the oil and try it again.

[Jimsun]

Don't panic, it might be a float sticking and a little oil and gas getting where it shouldin't be. I'd put it on the center stand, check the plugs and float levels, clean off the oil and try it again.

I hope the video uploads to give you an idea of what I'm talking about.

to check the float level, I should remove the carbs full right?

[LesterPiglet]

Jeebus christ. 
This video is currently being processed.

[LesterPiglet]

I can hear it's not going on all four anyhow. Apart from that I'm not sure. Broken ring?

[Puntas13]

If it was laying on its side oil could have seeped past the rings and into the cylinder. If that was the case it would obviously cause a smoking issue but it would also raise the compression resulting in weeping gasket and lord knows what else.

[Jimsun]

Whats the best course of action in this case? Ive also used mineral oil instead of syn or semj syn

By the way, all 4 pipes are hot!!

How do i turn the air mix screw?

[LesterPiglet]

What happens when I turn the airscrew out - richer or leaner?
If your airscrew is on airbox side of carb, turning out will lean mixture; opposite if airscrew is on engine side of carb.

http://forums.sohc4.net/index.php?topic=5410.0

[Bootlegger56]

I don't like that noise.  Where is it coming from.  Take a mechanics stethoscope or a long screwdriver to your ear and locate the source.  I could be wrong but it sounds metal to metal to me.  Since you did the cam chain adjustment....Make sure the cam chain adjuster lock nut has not come loose ...... or is still there.

[Jimsun]

Thanks. It seemslike its coming from the first cyl. Ill check up on it later today wheni have time.

I don't like that noise.  Where is it coming from.  Take a mechanics stethoscope or a long screwdriver to your ear and locate the source.  I could be wrong but it sounds metal to metal to me.  Since you did the cam chain adjustment....Make sure the cam chain adjuster lock nut has not come loose ...... or is still there.

What happens when I turn the airscrew out - richer or leaner?
If your airscrew is on airbox side of carb, turning out will lean mixture; opposite if airscrew is on engine side of carb.

http://forums.sohc4.net/index.php?topic=5410.0

[flybox1]

look at the last picture you posted.  your brass mixture screw is on the airbox side of the carb slides. 
because it is on this side controls the amount of air in the idle mixture. 
IN = less air in the mixture(richer)
OUT -  more air in the mixture (leaner)

[Jimsun]

look at the last picture you posted.  your brass mixture screw is on the airbox side of the carb slides. 
because it is on this side controls the amount of air in the idle mixture. 
IN = less air in the mixture(richer)
OUT -  more air in the mixture (leaner)

Update:
The squealing noise seems to have disappeared completely. I have cleaned the fins and the oil hasn't leaked out. Maybe it's because i've only ridden it for 15ish minutes? I would have ridden longer but the temperature at the moment is -2C or 28F and my fingers were freezing (don't have proper gloves)

thank you. I read the link given by Lester and this is what i did and got this reading throughout all of my plugs. Do you guys think this is the right colour? It looks about tan/bronze-ish

Im running full stock. air box, air filter, carbs, 4-4

How do I tune the carbs?
1.  Pick the main jet first.  You can take a plug reading at wide open throttle.  Accelerate over a long distance (preferably uphill) getting into 5th gear and keeping throttle fully open.  When fully tapped out, grab the clutch and hit the kill switch.  The motor should stop immediately, then look at the plug.  Should be tan, but not too dark.

[flybox1]

it looks ok, but is it from general riding, or from a specific, sustained, throttle position (which is how an accurate plug chop should be done)?

[Jimsun]

it looks ok, but is it from general riding, or from a specific, sustained, throttle position (which is how an accurate plug chop should be done)?

Well what i did is this. I rode generally for about 15 minutes keeping the rpm between 4.5-7k. on my way home i hit 3-4k rpm due to turns and dirt (approx 20 seconds) then my street, which is a straight, i went WOT for 5 seconds which reaches 6.5-8k rpm. then grabbed the clutch -> kill switch -> stop in front of my house -> check plugs. The picture above is the end result.