Rocker arm not moving

[guzzihank]

The left exhaust rocker arm on my 1970 Ambo is not moving. I have the valve covers off and can see that the other three arms/valves move when i turn it over. What would be my next move here? I am moderately mechanical and learning more with each day.

Thanks in advance.

 

[phildaulton]

Maybe some Amsoil would help (just kidding, see thread listing above this thread). Can you see the pushrod? Is it moving when you turn the crankshaft? Does the bike run? Perhaps the adjustment has backed off (loosened).

 

[john zibell]

Get the left cylinder to TDC just after the intake valve has closed. In this position the exhaust should be closed also. Remove the exhaust rocker and then the push rod. Check to see if the push rod is straight and in tact. If in question, remove the intake rocker and use the intake push rod for comparison.

 

[guzzihank]

Maybe some Amsoil would help (just kidding, see thread listing above this thread). Can you see the pushrod? Is it moving when you turn the crankshaft? Does the bike run? Perhaps the adjustment has backed off (loosened).

I will take a closer look . When i last looked I did not see any movement. The rocker arm on the exhaust is not being pushed.

 

[guzzihank]

Get the left cylinder to TDC just after the intake valve has closed. In this position the exhaust should be closed also. Remove the exhaust rocker and then the push rod. Check to see if the push rod is straight and in tact. If in question, remove the intake rocker and use the intake push rod for comparison.

Thank you, I will try and get to it tonite. Someone suggested that it could be the lobe on the crankshaft. What do you think, have you heard of them wearing down etc., or it more likely a problem with the push rod. I recently had the local shop adjust the valves, is it possible that they had a hand in this happening. Willl let you know what I find on the push rod.

 

[john zibell]

Get the left cylinder to TDC just after the intake valve has closed. In this position the exhaust should be closed also. Remove the exhaust rocker and then the push rod. Check to see if the push rod is straight and in tact. If in question, remove the intake rocker and use the intake push rod for comparison.

Thank you, I will try and get to it tonite. Someone suggested that it could be the lobe on the crankshaft. What do you think, have you heard of them wearing down etc., or it more likely a problem with the push rod. I recently had the local shop adjust the valves, is it possible that they had a hand in this happening. Willl let you know what I find on the push rod.

Crankshaft won't lose a lobe but the camshaft might. Highly unlikely that the lobe has worn away. If the local shop really made a mistake on that exhaust adjustment, it may have caused a bent rod. If the clearances on the other three valves are correct, then the suspect valve probably was set correctly also. You just need to dig in and find the failure, then you can look for the cause.

 

[guzzihank]

I removed the rocker arm last nite and was able to pull the push rod out. It had actually broke in half and then fused the two pieces together to create a shortened rod. I will now try and get a new push rod. I tried to pull out the valve and the spring on top of it but it did not come out freely (should it). Is it possible that the valve is frozen/stuck? I did not try too hard to pry it out as I was unsure whether it just pulls out.

What causes a push rod to break? Is this normal, common or rare?

 

[Chuck in Indiana]

The valve *could* be stuck, but.. no offense intended.. if you don't know how this stuff works, maybe you are in over your head. Take a copper hammer (or use a piece of aluminum, plastic, wood, or something that won't hurt the valve stem and a ball peen) and hit the end of the valve stem. If all is well, the valve will open and the spring will immediately close it. Understand? If that happens, you can source a new push rod, adjust the clearance, and you're (probably) good to go...
If you don't completely understand what is happening, take it to the mechanic.

 

[pokeyjoe]

I recently had the local shop adjust the valves, is it possible that they had a hand in this happening.

How did it run after the adjustment? I can't help but think that the problem started there with no clearance or something.

 

[guzzihank]

The valve *could* be stuck, but.. no offense intended.. if you don't know how this stuff works, maybe you are in over your head. Take a copper hammer (or use a piece of aluminum, plastic, wood, or something that won't hurt the valve stem and a ball peen) and hit the end of the valve stem. If all is well, the valve will open and the spring will immediately close it. Understand? If that happens, you can source a new push rod, adjust the clearance, and you're (probably) good to go...
If you don't completely understand what is happening, take it to the mechanic.

No offense taken. I am trying to learn as I go. I took the bike in earlier in the season for a tune-up to the local dealer. When I picked it up they told me the mechanic was 27 years old and had never worked on a bike this old (42 years) and all he could do was adjust the valves. The mechanic said it now runs qieter and should be okay, no more ticking.

I now understand how the valves work and that they do not pull out from the top. I am hoping it is not stuck and a new push rod will do the trick. I was just trying to figure out if something else caused the rod to break or does this just happen.

 

[pokeyjoe]

The mechanic said it now runs qieter and should be okay, no more ticking.

Ticking is not a bad thing on a Guzzi. Hearing those tappets makes me feel better. At least I know they are not too tight.

 

[Trout]

Most likely the valves were not adjusted correctly (set to tight) by the young mechanic. Valve noise is common with these bikes after awhile you will get used to it.

The intake is set at .004 & the exhaust is .008 . If you have good basic skills & mechanical understanding you can learn to work on this bike yourself & many here will help you along the way.

Do you know how to find top dead center on the pistons so the valves can be adjusted correctly?

Do you have a good feeler gauge?

Do you have a service manual or parts book? If not I have both in a PDF file that I will be happy to email you.

Trout

 

[Chuck in Indiana]

Certainly the "no more ticking" is a bad thing. Possibly he adjusted them too tight... and *could* have caused your problem. Not necessarily of course.. it *might* be coincidental. :shock: Is there an experienced Guzzi Guy around that could walk you through the valve setup? It's simple enough if you have the correct tools and know how.

 

[john zibell]

Just check my factory (Premier Motors) manual. It states 0.15mm (0.0059 inch) and 0.25mm (0.0098 inch). So I'd use a 0.006 gauge for the intake and 0.010 gauge for the exhaust.

 

[Chuck in Indiana]

Just check my factory (Premier Motors) manual. It states 0.15mm (0.0059 inch) and 0.25mm (0.0098 inch). So I'd use a 0.006 gauge for the intake and 0.010 gauge for the exhaust.

this

 

[guzzihank]

Thanks to you all. I have ordered a new push rod and will install when it arrives. I do have a good feeler guage. I have the repair and parts manuals that I got off the Cycle Garden site. I do know how to use the pulley marks to get to the TDC. The only questionable is the TDC compression vs TDC intake. I have also gotten a tune guide off the Gary Bender site. I am grateful for all of the advice. The part will take about a week to 10 days to get here. Will be away for three weeks after that. Will let you all know how it goes in mid November.

 

[john zibell]

Thanks to you all. I have ordered a new push rod and will install when it arrives. I do have a good feeler guage. I have the repair and parts manuals that I got off the Cycle Garden site. I do know how to use the pulley marks to get to the TDC. The only questionable is the TDC compression vs TDC intake. I have also gotten a tune guide off the Gary Bender site. I am grateful for all of the advice. The part will take about a week to 10 days to get here. Will be away for three weeks after that. Will let you all know how it goes in mid November.

The marks aren't that reliable. Use a plastic straw (or similar device that won't damage the piston) in the spark plug hole to feel TDC. You will now when you are at the top of compression stroke by watching the actuation of the intake valve. While turning the engine in the correct direction (normal rotation) watch for the intake valve to start opening. Using the straw or similar object you can feel the piston travel down while the valve is open. Once the piston starts to come up and the valve closes you are on compression stroke. You can feel when the piston stops traveling at the top of the stroke. Do your valve adjustment at this point.

 

[Trout]

Just check my factory (Premier Motors) manual. It states 0.15mm (0.0059 inch) and 0.25mm (0.0098 inch). So I'd use a 0.006 gauge for the intake and 0.010 gauge for the exhaust.

My Bad! John is correct the specs I listed are for the V700. https://www.guzzitech.com/forum/post/q ... 0&p=72896# Dang! I hate it when I'm wrong.

 

[Chuck in Indiana]

Thanks to you all. I have ordered a new push rod and will install when it arrives. I do have a good feeler guage. I have the repair and parts manuals that I got off the Cycle Garden site. I do know how to use the pulley marks to get to the TDC. The only questionable is the TDC compression vs TDC intake. I have also gotten a tune guide off the Gary Bender site. I am grateful for all of the advice. The part will take about a week to 10 days to get here. Will be away for three weeks after that. Will let you all know how it goes in mid November.

The marks aren't that reliable. Use a plastic straw (or similar device that won't damage the piston) in the spark plug hole to feel TDC. You will now when you are at the top of compression stroke by watching the actuation of the intake valve. While turning the engine in the correct direction (normal rotation) watch for the intake valve to start opening. Using the straw or similar object you can feel the piston travel down while the valve is open. Once the piston starts to come up and the valve closes you are on compression stroke. You can feel when the piston stops traveling at the top of the stroke. Do your valve adjustment at this point.

And.. just in case.. normal rotation is clockwise viewed from the front.. again, no offense intended. Ya gotta learn sometime.

 

[guzzihank]

Thanks again for all of the advice. I was able to push down on the exhaust valve with the wooden end of a ball peen and get it to move. So the valve is not stuck. I will wait for the new push rod and should be back in business.

I will be using the 0.15 and 0.25 mm gaps.

While we are at it, I have gotten different numbers for the gap on the point. The Shop manual says 0.42-0.48mm, the guys at Moto International told me 0.35mm. Any thoughts?