Topic: Still on my quest to build a leak free motor

[scondon]

 I am under the impression now that oil just wants to escape these 750 motors and, much like ants finding a way inside the home, is destined to do so despite my best efforts

 This is my 4th motor rebuild, and after 4250 miles I am happy to say that the top end and crankcase seals are holding up beautifully. However, there is a good amount of oil now coating my oil filter housing and oil cooler adaptor. At first I thought that I just did not get a good seal on the adaptor during the last oil change, but on further inspection I found a whole new( to me) way for oil to escape.......The main passage plug in the crankcase, just above the oil filter housing(#'s 8 & 25 in this parts diagram)

http://www.cmsnl.com/honda-cb750k-750-four-k-77-us_model495/partslist/E++14.html

    Seems easy enough to order a new o-ring to replace the old one. Has anyone ever removed this plug?  Is it a tapered fit and I should get a new plug as well?

Glad it's something I can reach without pulling the motor

[rhinoracer]

I had been under the impression that Japan was the first to build leak free motorcycles. I guess the CB750 wasn't the one.

When building my motor I also set on a quest to make it leak free, ended up getting paranoid with all the possible ways for oil to escape from this flawed design so I stopped caring.

I wonder if there's an external top end oiling system, maybe racers know a trick or three. (I know my nickname's 'rhinoracer' but I raced off-road cars not bikes).

Oh, almost forgot. I don't know about the plug, s ;)orry!

[scondon]

I had been under the impression that Japan was the first to build leak free motorcycles. I guess the CB750 wasn't the one.

    I think the Japanese did a fine job and that it is this Irishman's efforts to duplicate their success that is suspect    In my defense, I did not touch this plug during rebuild. Guess the 30 year old o-ring just decided to call it quits

[750essess]

I have never seen one leak there . I bet it will be fun to get that out, it just has a slot to remove it and probably has some sort of thread lock on it.

[scondon]

I have never seen one leak there . I bet it will be fun to get that out, it just has a slot to remove it and probably has some sort of thread lock on it.

   Lucky for me that I have a couple of 'cases to practice with in order to see how much force is neccesary and how much damage to the plug results   I can do this over the weekend and will find out then what type of plug it is, but am hoping to get a jump on ordering what parts I'll need today.

[dusterdude]

sean,didnt know you built a harley.

[TwoTired]

What kind of oil are you leaking?

Does it get on your helmet, pods, or loud pipes?










 

[scondon]

What kind of oil are you leaking?

Does it get on your helmet, pods, or loud pipes?










 

   In an odd coincedence, the oil trickles down my right frame rail and drips off the lowest point, just above the collector of my super loud pipe where it then burns to vapor and drifts up to get sucked into my pods for re-introduction to the engine. What little vapor escapes the pods drifts further up to be trapped inside my fullface helmet, filling my nostrils with the sweet aroma of burnt semi-synthetic HP-4

sean,didnt know you built a harley.

   So that's why all these metric tools won't fit right

[dusterdude]

hahahahaha

[angeldeville]

I read the title and thought you were talking about SOHC 750's.... ohh wait... you are....WTF?

[Bodi]

No, no... they call that a "45".

[scondon]

  Wow, that plug comes out E-Z-P-Z   Probably didn't even need the impact driver. No tapered threads or thread lock, and just a thin o-ring. There is not much to this plug.

    I never thought about this plug and probably would have attributed the leak to the crankcase seam or oil filter housing had it not been for the amount of oil seeping out, which made it easy to spot. I'm sure there are more Honda's out there with weeping plugs.

      Replacement o-ring from servicehonda= $2.72

   Pretty happy that it's a simple matter/easy fix

[bwaller]

Good deal Sean, I don't think I've ever seen one leak before either.

[joeb]

Well Sean you never stop amazing me with new things to look at on my bike.   Well got some new feet put on it today picked up my wheels today and installed them and will break them in tommorrow on a ride in the hills I put on the Avon Road riders. Feel like riding tommorrow or Sunday??? 

[scondon]

Good deal Sean, I don't think I've ever seen one leak before either.

   It's me then, right?  I mean, it must be.....me. Somewhere, at some point, I must have done something to piss off the Japanese and they have sent an angry samurai spirit to reside in my garage to hack away at any unsuspecting seals that I did not cement shut with spackle and JB Weld

Feel like riding tommorrow or Sunday??? 

  Sounds good. How 'bout Sunday? That will give me a chance to do a temp fix on my leaky plug tomorrow.

SUPERSPORT SUNDAY........SUNDAY........SUNDAY!!!!!!!!!!