Pitted cylinder question

B

boulevard

Guest
I just cracked open the engine of my new old Cl360 today and found some pits in the cylinder wall (see photo) I honed it out and they are smooth and barely noticeable with my fingernail but still visible. Questions... Should I leave it? Bore it out? Buy another cylinder that is in better Condition off ebay? Thanks
4umadyme.jpg


Boulevard
 
If you can feel them, they COULD potentially become a problem. Some might say don't worry about it. Me personally, I like to say better to be safe than sorry. I would compare the price of replacing the jug vs the price of boring it out an sleeving it. Shop around, and you might find used jugs for VERY cheap that are in GREAT condition. Just my opinion.
 
boulevard said:
I just cracked open the engine of my new old Cl360 today and found some pits in the cylinder wall (see photo) I honed it out and they are smooth and barely noticeable with my fingernail but still visible
Click to expand...

It will probably be just fine. The key here is that the evidence of corrosion is at the very bottom of ring travel. 95% of the cylinder where the rings travel is above the pitting.

Rule of thumb, you can feel 1/2 thou with your fingernail, but not your fingertip. You can feel one thou with your fingertip.

I would suggest that you take the pistons and jugs to a machine shop, and have them check the piston clearance to be sure it is within service limits. If piston clearance is good, maybe hone that cylinder a little more.

I have seen cylinders much worse than that perform just fine. My preference is not to bore oversize if you don't need to. That can be for the next rebuild.
 
Great advice. I think I will just try it. One more question for the veterans... Can I get the jugs out while the engine is mounted on the bike. I have mine completely disassembled because I wanted to get the frame looking new.

So if I out it back together and it does need to be bored do I have to remove the engine again

Boulevard
 
Top end service can be done with the engine in the frame. It says so on page 31 of the factory service manual.

Now for a bit of a lecture. The fact that you asked that question implies that you either do not have the service manual, or you are too lazy to look in the service manual to answer routine questions about procedure.

The manual is your first source with regard to technical questions. For instance, if you were to ask what the service limit is for piston clearance, you would receive a well-deserved bitch slap. That information is in the service manual. We, as a group, are here to help you with whatever you need, but there is no excuse for not studying the service manual before you proceed with engine work. If you are doing engine work and you have not obtained a service manual first, you are an idiot. A free download of a PDF of the service manual is easy to find on-line.

Not saying you are an idiot, just expressing that you MUST have the proper reference material to do this job, and don't expect us to read the service manual for you. RTFM, as they say.

The service manual does have it's shortcomings, and those of us with actual experience can help you with the questions that the manual cannot answer, such as your first post, which is an excellent question.
 
AlphaDogChoppers said:
Top end service can be done with the engine in the frame. It says so on page 31 of the factory service manual.

Now for a bit of a lecture. The fact that you asked that question implies that you either do not have the service manual, or you are too lazy to look in the service manual to answer routine questions about procedure.

The manual is your first source with regard to technical questions. For instance, if you were to ask what the service limit is for piston clearance, you would receive a well-deserved bitch slap. That information is in the service manual. We, as a group, are here to help you with whatever you need, but there is no excuse for not studying the service manual before you proceed with engine work. If you are doing engine work and you have not obtained a service manual first, you are an idiot. A free download of a PDF of the service manual is easy to find on-line.

Not saying you are an idiot, just expressing that you MUST have the proper reference material to do this job, and don't expect us to read the service manual for you. RTFM, as they say.

The service manual does have it's shortcomings, and those of us with actual experience can help you with the questions that the manual cannot answer, such as your first post, which is an excellent question.
Click to expand...


+1
 
I can tell that I can count on alpha dog to say it as it is. I can respect that.... I have two manuals. One pdf and one hard copy that is covered in blood sweat tears and grease. however I was at work thinking about my options without a manual in hand

One more newbie question that is not covered in the manual. Where are people posting build threads and how does that work? I have heard about them and would love to check out people's bikes. I don't want to be an idiot and start a build thread under the wrong category either.

Boulevard
 
After reassembling I am getting 150 compression on that cylinder which bothers me so I ordered another cylinder.
Question: should I get another set of rings since I have ran the others on the last cylinder or can I use them again on the new one? I have about 15 minutes of run time on the old cylinder. Just trying to not waste money but I also want it done right. Thanks!

Boulevard
 
AlphaDogChoppers said:
150 compression on a new build is just fine. Are you OCD or something? :)
Click to expand...

151 PSI is Lower limit in manual. 171 is Spec.
 
Yeah, but it's a brand new build, not even a 100 miles to break it in. And is the compression reading a bit low from rings leaking or valves. Was a leakdown test done?

A rebore will give good compression readings right away, but a re-ring sometimes takes a little while to properly seat, you know 100 miles, maybe 500 miles. Not 15 minutes.

Even freshly lapped valves need a little run time to optimize their seal. The CX500 that I just rebuilt definitely ran better after he rode it a couple days.
 
AlphaDogChoppers said:
Yeah, but it's a brand new build, not even a 100 miles to break it in. And is the compression reading a bit low from rings leaking or valves. Was a leakdown test done?

A rebore will give good compression readings right away, but a re-ring sometimes takes a little while to properly seat, you know 100 miles, maybe 500 miles. Not 15 minutes.

Even freshly lapped valves need a little run time to optimize their seal. The CX500 that I just rebuilt definitely ran better after he rode it a couple days.
Click to expand...

I do not disagree with you, just wanted to make sure the op knew the correct values....

Also, the engine might of been cold, not warm.

The other item is the difference between the cylinders. The poster implied they are different, but I am not sure if he did both jugs or not....

The devil is always in the details....Many posts like this leave out important details....
 
Sorry to leave you all bickering while I work haha. Let's see if I can leave more details as I appreciate the help. I honed both cylinders, the right one had some pits. After honing I put new rings on. I am showing 150on right (the one with pitting) and 170 on left.

As for the ocd haha yes I do. You should see my work space.
7yra3utu.jpg


A lot of my questions just come from a lack of experience. The last rebuild I did had valves reseated and engine bored. It immediately had spec readings so.... Just want to do it right as I have been stranded way too many times for stupid reasons. I have even caught a vw beetle on fire on the side of the interstate long story. I have caught a van on fire. I have pushed numerous bikes home. Bad cylinder readings makes me think fouled plug in the middle of nowhere on the one day I forgot to bring an extra.

Boulevard
 
I like the answers you give AlphaDogChoppers, makes me wish I still lived in Philly.
 
boulevard said:
Sorry to leave you all bickering while I work haha.
Click to expand...

We aren't bickering, maybe nitpicking a little. :)

I think you should put some miles on that engine before you tear it down again. After a few hundred miles, do your compression test again.

I am not an advocate of tearing down an engine if it runs OK and doesn't smoke. I think smoke is your key here. Put 500-1,000 miles on it and see how it is. Yes, "doing it right" would probably involve new cylinder or rebore both cylinders, but I think it may not be necessary.
 
No bickering at all, just making sure you get a complete picture...happens all the time here....

I agree with ADC nearly all the time...I agree with his statement...if it doesn't smoke, run it in a little too....recheck
 
The FNG doesn't know that we can respectfully disagree or correct one another without rancor. It's all part of the conversation, and it all adds to our collective knowledge, which is really why I am here. I have learned a lot about these old bikes, beyond my actual experience, just by reading the forums.

As you say, we weren't disagreeing, you were just giving a little more comprehensive info than I was.
 
I genuinely appreciate the help. I am going to ride it for a while see what happens.


Boulevard
 
You must log in or register to reply here.

DTT Light or Dark

  • DTT Light
    • www.jadusmotorcycleparts.com
    www.lostapostle.ca/
    www.sparckmoto.com

    Spread the Love

    Back
    Top Bottom