Author Topic: Oil seeping past the APE main bearing studs under the motor  (Read 1107 times)

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Offline Dion

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Dion;

Have not seen this. did you use the oem washers?

Jay / Tech
On May 5, 2014, at 4:11 AM, Dion de Beer wrote:


Dear APE.
 
I purchased a set of main bearing studs from you for my Honda 750 sohc motorcycle.
After the build and run of the motor I noticed that oil was seeping past the main bearing studs under the motor.
I can confirm that I used the nuts supplied by you and that the nuts have been torqued down to your specifications.
 
Do you have a solution for this issue as the bike is raced and will fail  pre-race checks.
 
 
Kind Regards
 
dion

Offline Dion

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Re: Oil seeping past the APE main bearing studs under the motor
« Reply #1 on: May 12, 2014, 01:57:17 AM »
Hi Chaps, Can anyone shed light on this issue.   ???????

Offline Sam Green Racing

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Re: Oil seeping past the APE main bearing studs under the motor
« Reply #2 on: May 12, 2014, 03:53:35 AM »
Dion, perhaps one of the motor guys will chip in on this one.
Is the oil getting past just one or all of them?

Sam. :)
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Offline MRieck

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Re: Oil seeping past the APE main bearing studs under the motor
« Reply #3 on: May 12, 2014, 04:48:39 AM »
Did you put sealant on the mating surfaces of the main bearing saddles? It can be fixed without pulling the engine.
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Offline dragracer

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Re: Oil seeping past the APE main bearing studs under the motor
« Reply #4 on: May 12, 2014, 08:53:44 AM »
Did you put sealant on the mating surfaces of the main bearing saddles? It can be fixed without pulling the engine.
What Mike said!!!

Offline MCRider

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Re: Oil seeping past the APE main bearing studs under the motor
« Reply #5 on: May 12, 2014, 09:53:04 AM »
Not to steal Mike's thunder but I've been down this path and he helped me.  It is fixable.

First I can't remember putting sealant on the saddles, so I assume I did not. HEnce the studs leak. At Mike's suggestion, I loosened the offending nuts, put sealant on the threads let them set up, and replaced the nuts. No more leak. One of them was too hard to get to. So I simply gave it a skosh more with a cheater bar and it stopped.

It also looks like you used flange nuts, but omitted the washers. Washers will help, copper washers might help more.
« Last Edit: May 12, 2014, 09:55:39 AM by MCRider »
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Offline Dion

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Re: Oil seeping past the APE main bearing studs under the motor
« Reply #6 on: May 12, 2014, 11:25:37 AM »
Hi,  u chaps are great. Thanks for the help.  I need a bit of clarification, what do u mean by "saddles" are these the standard Honda washers?  If that's the case can u loosen off the flanged nuts, put sealant on the eom washers and to torque up the bearings as per the workshop detailed pattern?  Thanks for all the help guys.   

Offline Sam Green Racing

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Re: Oil seeping past the APE main bearing studs under the motor
« Reply #7 on: May 12, 2014, 01:02:38 PM »
As well as putting a little sealant on the washers, You could use dome head nuts.
The old Honda Benlys that I work on have one of the crank bearing and one of the head studs sharing oil passages.
Both these studs are capped by dome head nuts as standard because without them, oil gets out through the threads.

Sam. ;)
C95 sprint bike.
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CB92
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Offline MCRider

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Re: Oil seeping past the APE main bearing studs under the motor
« Reply #8 on: May 12, 2014, 02:06:19 PM »
Hi,  u chaps are great. Thanks for the help.  I need a bit of clarification, what do u mean by "saddles" are these the standard Honda washers?  If that's the case can u loosen off the flanged nuts, put sealant on the eom washers and to torque up the bearings as per the workshop detailed pattern?  Thanks for all the help guys.
The "saddles" are internal. They are the flat mating surfaces on either side of the main bearings, top case to bottome case. To a layperson it appears one could get away without sealing these, and just seal the perimeter of the cases. But as I have learned, all mating surfaces need to be sealed just in case. That just in case in this case is if you convert to studs (as I did too) there is more of a chance of oil wicking thru the saddle area to the studs, down the studs to the nuts (and washers) and out on the ground.

The first line of defense is the saddle area. APE's experience has probably been predominantly with people who knew to goop up the saddle areas.

The sad part about the external fix is we lose the continuity of the pattern of torquing the nuts. But better they don't leak, IMO. And yes, your description of the fix is correct: loosen the flange nuts or remove altogether, put gasgacinch or your favorite sealer on the studs threads, shove it up the hole with a QTip, goop the washers, let them a set up, and reinstall. I just did the 3 on mine that were leaking and I think I cured it.
« Last Edit: May 12, 2014, 02:13:04 PM by MCRider »
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Online Don R

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Re: Oil seeping past the APE main bearing studs under the motor
« Reply #9 on: May 12, 2014, 02:31:42 PM »
Hmm, I held the sealant back for fear of getting it in the bearings. We shall see if mine seals.
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Offline MRieck

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Re: Oil seeping past the APE main bearing studs under the motor
« Reply #10 on: May 12, 2014, 04:50:00 PM »
I ahd my customer find a good fitting oring and apply some silicone  sealer to that and push it just into the hole. Area has to be thoroughly cleaned with brake cleaner first. Some sealer on the washer is a good idea too. That fix has held in there for years. You have to put sealant on the saddle tops....keep it .040 away from the bearings. this is in many, many manuals that came after the CB's...God knows they contain a ton more info that is applicable to every engine build.
 I use a small hobby brush with cut down bristles to apply the 1194...you get good even coverage and nice control.
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Offline BPellerine

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Re: Oil seeping past the APE main bearing studs under the motor
« Reply #11 on: May 13, 2014, 04:12:47 PM »
wonder what the org sealant was looks almost like it was kind of runny and brushed on with the excess running down the cases brown in colour.bill
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