Topic: Newbie here

[waldezy]

Hey all,

I've been stalking this forum for a few weeks and finally decided to join. Finally have my 74 cb750 up and running. Top end rebuilt along with the carbs. Finally have it running perfectly except for one problem...oil leaks from a few places. Seems to be leaking right on where the 4 pipes converge from the bolt just below the oil filter. Also have some slight leaking from the inside cylinder tappet caps/bolts. Any ideas on how to stop that, or will I need to pull the bottom off try to reseal it? Anyone have a quick fix? Thanks in advance.

Here's a pic of her... http://imgur.com/cUKDufG

Vid of a walk around...

Vid of her running...

[Ericcb750]

Hey Waldezy, Welcome to the forum...you won't find a better group of SOHC brainiacs anywhere. Super helpful and know more about these bikes than most. I've been around for a couple years and have come to learn a lot about these bikes. I'm sorry but i'm not quite sure what you're referring to about the "where the 4 pipes converge under the oil filter"

Sometimes this stuff is kind of confusing so it may be easier to post a photo and point to the areas you're referring to? A lot of times on the top you can get oil leaks from the little black pucks/nickels under the cam towers....WHen you re-built the top end did you seal the bottom of those? Those holes go directly to the inside of the head and will leak out toward your pipes/head gasket area.

Best bet, post some photos and we'll all probably be able to help you out. Best of luck, welcome to the SOHC 4 Forum.

[waldezy]

Thanks for the response,

I have 4 in 1 exhaust which seems to merge right underneath where the oil filter and the engine meet. Oil is dripping from the frontmost middle bolt on the pan. The engine was sent away and was rebuilt so I'm not sure if he did or not. I'll try t post some close pictures tomorrow.

[dusterdude]

Welcome

Sent from my LG-D850 using Tapatalk

[DaveBarbier]

Best bet is to clean the oil off and dust the area with baby powder. Once it starts leaking it'll be much more obvious where it's coming from. If it's leaking from a bolt on the oil pan then hopefully it just needs a new oil pan o-ring.

As for the other oil leak, when you say "inside cylinder tappet caps" you mean the tappet covers on either cylinder 2 or 3, right? Those caps also have o-rings under them that are simple to replace. Sometimes, because those caps are pretty fragile, they can crack which can lead to oil seeping out. In that case you'll need a new tappet cap.

Nice bike and welcome!

[waldezy]

Thanks!

That is correct, cyl 2 and 3. I'm using full synth oil - I've read other forums saying it'll leak a little more when using synthetic oil vs conventional. Oh well, I'll take a look at those rings. Thanks for the pointers.

[waldezy]

Hey Waldezy, Welcome to the forum...you won't find a better group of SOHC brainiacs anywhere. Super helpful and know more about these bikes than most. I've been around for a couple years and have come to learn a lot about these bikes. I'm sorry but i'm not quite sure what you're referring to about the "where the 4 pipes converge under the oil filter"

Sometimes this stuff is kind of confusing so it may be easier to post a photo and point to the areas you're referring to? A lot of times on the top you can get oil leaks from the little black pucks/nickels under the cam towers....WHen you re-built the top end did you seal the bottom of those? Those holes go directly to the inside of the head and will leak out toward your pipes/head gasket area.

Best bet, post some photos and we'll all probably be able to help you out. Best of luck, welcome to the SOHC 4 Forum.

See the attached picture. I've circled where oil is coming from. The oil isn't pouring out, however when the bike has been warmed up and I come to a stop, seems the oil has dripped onto the wrap I have on the exhaust and causes smoke.

[70CB750]

That bolt is one of many that holds engine halfs together, it screws into the top half.  There is no reason for oil to be coming out of there.

Welcome to the forum, btw.

[flybox1]

That bolt is one of many that holds engine halfs together, it screws into the top half.  There is no reason for oil to be coming out of there.

Agreed, but it is a low spot for anything running down the front side of the engine, including from the oil filter. 
Clean and dry the area, and spray with talc.   ride and look for the wet spot to find the source.

[riffman12]

I would guess (as the others said) that the oil is not actually coming from that bolt.

More likely you are missing the o-ring on your oil filter bolt (or it's worn out) causing oil to seep out, run down the filter housing, and collect on that bolt head.

[70CB750]

That bolt is one of many that holds engine halfs together, it screws into the top half.  There is no reason for oil to be coming out of there.

Agreed, but it is a low spot for anything running down the front side of the engine, including from the oil filter. 

Exactly.  I have money on the oil filter o-ring too.

[waldezy]

Thanks to all who've replied. I'll have to get that a check. I'm assuming I can take the filter off without draining the pan - only oil in the filter itself will come out?

[70CB750]

Hmm, never tried that, but I believe only oil from the filter will spill.

But observe it first. if it comes from the filter, there will be an oil path tot he bolt.  I used white chalk before to trace a leak.