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Discussion Starter · #1 ·
Hello all.

I have been lurking on this fine website for a couple of months now and have really appreciated the vast amount of information contained here. I live in Broomfield, CO (Northern suburb of Denver) and have recently acquired a 1969 CL350. I have almost finished a 1981 CB900 which was the first bike I did any serious work on. That bike came to me with mostly cosmetic, electrical and carburetor issues but was a great learning experience. Next up is this CL350 which is going to need a little more work. I was able to get it running after cleaning the carbs, changing the spark plugs, adjusting the cam chain tension, adjusting the valves and soaking the engine in Seafoam for 4 days, but the resulting compression test was 115/115 and it's leaking oil from the head and base gaskets on the left side. It shows ~23,000 miles on the odometer but I believe the engine was rebuilt at one point because I can see a little bit of after market gasket material sticking out around the head. So, I am planning to take the motor out and see what needs to be done. I have never been inside an engine before and am excited and nervous. I am looking forward to sharing with you the journey.

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welcome - oil leaks from the head gasket are fairly common as they age, and/or have been apart by those who aren't familiar with best practices on them. It's a fairly simple engine so it won't be a huge challenge for you, and you'll get all the help you need from the many knowledgeable 350 people here.
 

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Welcome from Georgia, bike looks good.

Don't worry too too much, this place will have you up and running in no time. I'm in the middle of a complete rebuild myself, and I too have never been inside of an engine, so I'm learning as well.

Like ad above said.....these seem/are purdy simple engines.
 

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Welcome! 115 on both sides is not terrible depending on what type of compression tester you are using. I know for a fact using one with a rubber hose reads low and some testers that are meant for larger engines will have a hard time reading correctly on small displacement cylinders. My cheap Harbor Freight one reads about 10-15 PSI low on both my bikes but they both run fine, no burning of oil or struggles that come from a low compression engine. If it pulls strong and doesn't look like a 2cycle when its running it may very well be just fine.

Glad to see some more CO members on the site, I'm up in Greeley.
 

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Discussion Starter · #6 ·
Hey Frogman.

Yes, I first used the Harbor Freight quick-connect tester (the slightly more expensive of the two they carry) with the long rubber hose and was reading 75/75! :( I read about the variations you can get depending on tester and engine. I ordered a different one from Amazon, don't remember the brand off hand. The 115/115 isn't a MAJOR concern, but the bike really runs like crap. I have an '81 CB900 that is 125 across all four cylinders and it runs like a top nd has minimal leakage. The other question mark on this '69 is the fact that it has 32mm OKO carbs. I've been through them completely... they look like copies of the Keihin design so I'm familiar with how they work. Totally clean and, I think, set-up about right. With the compression and the fueling both in question (plus the fact that it's leaking pretty badly), I figure I might as well learn how to tear a motor down.

Drive safe tomorrow. We got quite a bit of down down here in Broomfield today.
 

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32mm carbs on a stock 350? IIRC they come with 28s from the factory. Unless there are decent engine mods, it sounds over-carbureted
 

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Discussion Starter · #9 ·
Yes, that is correct. 32's are to big for that motor. I'd like to throw some Mikuni VM30's on it but, based on what I've read here, that's not going to be an automatic improvement either.
 

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Discussion Starter · #11 ·
That is a very practical suggestion. I hadn't stopped to think of just putting OE carbs on it. Why spend a little when you can spend a lot is one of my problems with my bikes. Character flaw I assume :)
 

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It's easy to get carried away during the planning and parts gathering stages, especially when many things you like (or believe you will) are readily available. At least with a decent set of used stock carbs, you'd only be up against getting them clean and properly set up, as opposed to all the potential unknowns with the closest set of aftermarket carbs
 
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