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Discussion Starter #1
Ok, so I am by no means anywhere near a motorcycle mechanic. I just bought a 1976 CB550 when I looked at the bike it ran fine and sounded great. I drive an SUV and the only way I had to get it home was to lay it on its side in the back for a two hour drive. When I got it home I unloaded it, put it on the center stand, and left it sit over night. This morning I took it out, started it, and now it knocks and blows a bit of blue smoke. I think that while it was lying on its side that oil may have gotten up past the rings. Now I am looking for the proper way to fix this problem IF this is the problem. Talking to a friend he told me that I chould change the oil and let the rest burn off but the knocking worries me that I may do more damage.

If anybody has any suggestions of how to fix this problem or has other ideas of what it could be please let me know.

Thanks
 

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What side did you lay it on ? The right side?
Maybe you smashed the points cover and it is hitting on something.
The Oil for now i would not worry about it.
Could just be vavle seals that are worn.
Let us know what happens

84 FJ110
77 CB50
76 CB 550 sitting in boxes
 

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Discussion Starter #3
I actually had it lying on the left side. I would have no problem trying to burn it off except that the knocking has me worried. Once I apply throttle the knocking seems to get quieter or the exhaust makes it so I can't hear it as well. I guess my biggest worry is doing damage. I don't want to take it to a mechanic if I don't half to.
 

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a inspection of both left and right side cases shows no signs of damage i guess right ?
does pulling the clutch in makes any difference
can you put a screw driver on the block and listen to the lower end of the motor.
I dont know your mechanical level but i guess you are thinking this is a rod knocking. if you blip the throttle a little can you hear it knock then.
Was the motor hot when you checked it out. Did you check the Oil level could it be the rocker arms ?

84 FJ110
77 CB50
76 CB 550 sitting in boxes


Edited by - lance on Feb 07 2006 9:34:56 PM
 

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Pull the plugs and turn it over with the starter to blow any oil out of the cylinders. Put the plugs back in, check the oil, then start it.
Worse case scenario is that the left side cylinder filled with oil, then when you started it, it tried to go into hydraulic lock and broke something. Usually something important like a piston or wrist pin.
A four cylinder bike has three other cylinders to start and drive the piston in the oil filled cylinder up against the oil...which it can't compress...so something has to give.
Although it is rare for enough oil to get past the rings or valve seals to fill the combustion chamber.
Excessive oil in a cylinder will also cause pre-ignition...commonly reffered to as "knock".
JohnnyB
 

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jbranson
true dat i was not thinking of Oil getting past the rings just laying there but you are right it is possible if enough leaked past if that was the case the motor was pretty loose and probably needed to be rebuilt any way

84 FJ110
77 CB50 Cafe bike now
76 parts bike
74 Suzuki t500 soon to be on the road
 

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I guess as the H1's had a vacuum operated petcock and often when a novice had the tank off they'd reconnect a fuel line where the vacuum line was supposed to go, so that crankcase/cylinder would fill with fuel and they'd kick it over. One of the other cylinders would fire and VOILA', bent rod as liquid no compresso'. Hope that something like this didn't occur on your bike.

Dgy
 

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I guess as the H1's had a vacuum operated petcock and often when a novice had the tank off they'd reconnect a fuel line where the vacuum line was supposed to go, so that crankcase/cylinder would fill with fuel and they'd kick it over. One of the other cylinders would fire and VOILA', bent rod as liquid no compresso'. Hope that something like this didn't occur on your bike.

Dgy
 

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Discussion Starter #17
Ok, I am such a newbie. The knocking seems to be coming from the clutch area along with number 3 not firing, causing the smoke. Number 3 is not getting any fuel I am assuming becuse of some sort of blockage in the number 3 carb. Now as you guys can tell I don't know much but I read somewhere that the knocking can come from the carbs not being in sync? So I am hoping that my problems are all carb. I took the carbs off today and I am taking them to "The Shop" in Milwaukee WI. They quoted me $150 to $200 dollars to rebuild them. Other places quoted me around $350+. What do you guys think of this price? I would do it myself if I didn't care when I would be able to ride the bike but being my only bike right now I don't want to take the chance. Live and Learn.
 

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Discussion Starter #18
Ok, I am such a newbie. The knocking seems to be coming from the clutch area along with number 3 not firing, causing the smoke. Number 3 is not getting any fuel I am assuming becuse of some sort of blockage in the number 3 carb. Now as you guys can tell I don't know much but I read somewhere that the knocking can come from the carbs not being in sync? So I am hoping that my problems are all carb. I took the carbs off today and I am taking them to "The Shop" in Milwaukee WI. They quoted me $150 to $200 dollars to rebuild them. Other places quoted me around $350+. What do you guys think of this price? I would do it myself if I didn't care when I would be able to ride the bike but being my only bike right now I don't want to take the chance. Live and Learn.
 

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quote:
Ok, I am such a newbie. The knocking seems to be coming from the clutch area along with number 3 not firing, causing the smoke. Number 3 is not getting any fuel I am assuming becuse of some sort of blockage in the number 3 carb. Now as you guys can tell I don't know much but I read somewhere that the knocking can come from the carbs not being in sync? So I am hoping that my problems are all carb. I took the carbs off today and I am taking them to "The Shop" in Milwaukee WI. They quoted me $150 to $200 dollars to rebuild them. Other places quoted me around $350+. What do you guys think of this price? I would do it myself if I didn't care when I would be able to ride the bike but being my only bike right now I don't want to take the chance. Live and Learn.
Easiest way to tell which cylinder is not running is to check the exhaust pipe temps after running for 10-15 seconds. If its not running on #3, that pipe will be cold/cool.

I consider it VERY easy to clean out carbs. You don't even need to full disconnect the throttle cables if that's a pain. You need to:
1) take the tank off
2) drain the fuel out of the carbs via the float drains (if your carbs have them. They'll be screws on the sides of the float bowls)
3) loosen the clamps that hold the carbs to the engine. All 4 of them.
4) pop the carbs off and flip them upside down
5) with a good phillips head screwdriver, remove all 4 screws from the bottom of one float bowl.
6) Clean out any schmuck. Carefully remove any brass bits with holes in them. Those are the jets. Clean them with carb cleaner. Do not poke them with anything to clean them out.
7) put the jets back where you found them. Don't over-do the tightening.
8) move to next carb.

For $150, are they just cleaning them or replacing the jets? Its about 2 hours of work, so $150 = $75/hr which is about what most shops charge per hour.

$350? That's way out of line. They're quoting that because they don't want to touch your bike.
 

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quote:
Ok, I am such a newbie. The knocking seems to be coming from the clutch area along with number 3 not firing, causing the smoke. Number 3 is not getting any fuel I am assuming becuse of some sort of blockage in the number 3 carb. Now as you guys can tell I don't know much but I read somewhere that the knocking can come from the carbs not being in sync? So I am hoping that my problems are all carb. I took the carbs off today and I am taking them to "The Shop" in Milwaukee WI. They quoted me $150 to $200 dollars to rebuild them. Other places quoted me around $350+. What do you guys think of this price? I would do it myself if I didn't care when I would be able to ride the bike but being my only bike right now I don't want to take the chance. Live and Learn.
Easiest way to tell which cylinder is not running is to check the exhaust pipe temps after running for 10-15 seconds. If its not running on #3, that pipe will be cold/cool.

I consider it VERY easy to clean out carbs. You don't even need to full disconnect the throttle cables if that's a pain. You need to:
1) take the tank off
2) drain the fuel out of the carbs via the float drains (if your carbs have them. They'll be screws on the sides of the float bowls)
3) loosen the clamps that hold the carbs to the engine. All 4 of them.
4) pop the carbs off and flip them upside down
5) with a good phillips head screwdriver, remove all 4 screws from the bottom of one float bowl.
6) Clean out any schmuck. Carefully remove any brass bits with holes in them. Those are the jets. Clean them with carb cleaner. Do not poke them with anything to clean them out.
7) put the jets back where you found them. Don't over-do the tightening.
8) move to next carb.

For $150, are they just cleaning them or replacing the jets? Its about 2 hours of work, so $150 = $75/hr which is about what most shops charge per hour.

$350? That's way out of line. They're quoting that because they don't want to touch your bike.
 
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