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Discussion Starter · #1 ·
Cl350 1973 had the bike since 1995. Always remember the fins being like this. My other air cooled bike has a similar stain and pattern.
Is this a blown head gasket or is it impossible to tell from pics? Been sitting 12 years ready to bring her to life. Is the head gasket an engine-out procedure?
BTW the wet oil is MMO I had in it to get the cylinders lubed. It spat up all over so the wetness is from that. Im more concerned about the brown marks.
20181225_125824.jpg
Tried to get a closeup.. for soem reason it rotated, pic is rotated left 90 degrees.
20181227_214546.jpg
 

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It looks pretty juicy, but i dont think I could conclude from the photos.

You will need to pull the engine to replace.
 

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A compression test could answer this.....but from pic, staining appears to be above head to cylinder joint.
 

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Discussion Starter · #5 ·
Thanks for answers. I need to tackle the valve adjustment and am currently rebuilding the carbs so I cant do a compression test yet. I also remember the engine needs to be warmed up to get an accurate reading.
Is there any risk replacing the head gasket? I mean if I take it apart could the head be warped an never seal again etc..
 

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It all depends... What are your plans for this bike? To get it running and sell it, to restore it, or cruise around on?
 

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Discussion Starter · #7 ·
Restore. Keeping it forever. I'll be riding it too. Like many ive had the bike 25 years and it has high sentimental value.

I'm trying to decide what level to take it for now. I do see that common motor will regrind camshaft so now may be a good time to get that done. But not sure how deep to go yet. Is there a thread on what all i should check out?
 

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How many miles are on the bike? These bikes are fully capable of going a hundred thousand miles. I have never really seen one just worn out. Most of the time they are rebuilt because of neglect, abuse, or someone just thinks they need to rebuild them. Also, just because some internet parts supplier with "Moto" in their name offers something for a bike does not mean it needs it.
TOOLS
 

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The above advice is good... To get it running first before moving forward.

In addition, I am of the mindset that all these 350s will need a rebuild at some point, to service the hardened cam chain tensioner rollers. They will eventually come apart, so may as well deal with sooner than later. Perhaps if its ridden gently and sparingly then it's a nonissue. Mine sees a fair amount of action. However, my current engine hasn't had the rollers replaced yet, but it's a matter of time before I start seeing chunks of rubber in the oil. Keeping up with adjustments I'm sure helps.
 

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Discussion Starter · #11 ·
Here is my mindset:

Back in 2001 or so I let my brother borrow the bike as his primary mode of transportation. he beat the f** out of it. I also remember him adjusting the valves by "ear" and he went to both extremes on the adjuster. He also dumped the bike and the shifter hit the stator cover and cracked it, I fixed with epoxy. The clutch was slipping as well probably due to him putting car oil in it but that may not be the reason. I got the bike back from him and never rode it again. So I am under the impression he ruined it and I am very negative about it. My assumptions are Ill have to fix everything and I am ready to spend at least $1K getting it to be better then it was back in 1994. I assume the valve camshaft has wear or pitting and I assume its ok to just get it done while there are people around that can do it. Perhaps that is a bad mindset.

When I was 15, I also did not do a good job maintaining it for lack of tools. A distant family member sent me a large set of craftsman tools back in 1995 or so. By that time I had purchased a 1977 plymouth volare and that took all my time and tools. I still rode the bike sometimes in disrepair as the plymouth was absolutely junk. I finally had that car fixed and sold it off and went into the air force. Ironic.

Is it possible to pull the valve cover off without removing the engine? I noticed its affixed to a mount against the frame. I just want to "do her right".

The bikes spedo say 10K miles but Im certain at some time the spedo wasnt working. However Id assume it cant be more then 15K miles and probably closer to 12k.

I do like your plan, lets get it running and assess it. Carb rebuild, timing adjustment, valve adjustment etc.. It needs new cables and probably spark plug wires. Its a very needy bike.
 

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On a stock unmolested frame there's not enough room. You can grind away some of the stamped backbone to gain access, but not sure the point since you can't really go any further than the valve cover. Studs keep the rocker box from coming off.

As for your bike, it all sounds mild and it seems you have a good idea of what it needs and unless you find a bunch of ferrous metal in your oil slinger, then I'm sure you cam and rockers are fine. Just clean up the area around the head gasket and keep an eye on it, but as others said, the photos didn't indicate there was anything in that particular area.

As for your carb question... I'm cheap and lazy. I usually like to make sure the pilot circuit is clear, float bowl is clean, piston diaphram is good, and then run the carbs without tampering a whole lot with it.
 

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Discussion Starter · #13 ·
Need another piece of advice. I drained the oil and found some metal in the filter and a piece of rubber probably from the roller. Here are some pics. I do not think I ever adjusted the cam tension, and it did no appear to be putting any tension on the roller at all when I took it off.

So with this new information, do things change? Continue to get it running or pull the motor?

IMG_20181229_205540_01.jpg
20181228_223037.jpg
20181228_231050.jpg
 

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The roller looks about right for it's age. You can probably get it running and enjoy it for a few miles before it totally fails. Just keep the tensioner tensioned and check the slinger every 300-500 miles (<<< total arbitrary number) and listen for louder than normal rattling or rumbling.
A poorly tensioned cam chain will rub against the cam/rocker box and you'll get a bunch of aluminum shavings in your slinger. No real harm to the engine as long as it's not left too long.

The slinger looks surprisingly clean compared to others I've seen. You should be good to run though. Just keep an eye out for more metal and rubber bits. Also, make sure to keep valve clearance in spec.
 

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The tensioner roller looks pretty rough. It's do it now, or do it later... but it will have to be done if you plan to get any long-term reliability from the engine. They eventually get hard and come apart, but not adjusting the cam chain helps that along too
 

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Discussion Starter · #16 ·
Thanks guys for the input. So Ill continue with the original plan. My parts will be here later this week. Ill adjust the tension, adjust valves, and then do the timing.
Add Oil then see what else I need. My goal is to get it running ok then test compression to make a determination and what to do next.

Given I plan to keep this bike forever, I will be doing a full restore including a frame painting eventually. But Ive never rebuilt an entire engine so I have risk if I take it apart.

I used to work on Jet engines in the Airforce so Im no stranger to building up complex things, just never done a reciprical engine before!
 

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Discussion Starter · #17 · (Edited)
I did the procedure for adjusting the cam chain tensioner. There is mark where the tensionor was set before. After I put the timing mark in place (alight the to the LT mark AFTER the left intake valve opens, have to hold it there by hand) the tensionor is now putting less pressure then it was before. So this means someone set the tensionor with slack in the chain. I was going to take a pic gotta let phone charge. But its about 1/2 of centimeter back.

With the way I am setting it per may clymer manual, the chain is tight behind the tensionor. SO maybe thats why it got eaten?
 

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I set the tension approx 90-100 degrees past tdc. It's the point where all the valves are closed and there's no pressure on the cam. Remove all the inspection covers and continue rotating til all rockers are loose
 

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Discussion Starter · #20 ·
Correct me if Im wrong, but the manual doesnt have a cam chain tension prcedure does it?
 
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