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Discussion Starter #1
So I'm cleaning up my sohc 250 engine and there is a blue rubber stuff where the top and bottom gearbox cases join. Tell me I'm right in assuming a) Honda didn't apply this type of gasket when they built their engines and b) therefore my 15k miles engine has been apart?
 

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Well now, THAT's a relief! With a title like "cleaning my bottom" I was never happier to find a thread about "form a gasket!" :eek:

...come to think of it, this is the first time I've ever been happy to find a thread about form a gasket. :D
 

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66Sprint
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Well, yes.... Because that sealing material is likely either a RTV or a silicone sealant, and both types tend to extrude "globs" of semi-hardened material that break off and ultimately end up clogging oil passages within the engine....

There IS a blue sealant called Hylomar which could be OK, IF it was properly applied, but that is at best a 33% chance of success vs a 66% chance of catastrophic engine failure...... I don't like those odds against ......

Disassemble, scrape off that mess, clean out the sump and inspect and clear all internal oiling passages...Particularly the oil pickup screen, oil pump, and filter....Inspect ALL bearings, journals, and bearing surfaces (plain bearings).. Then reassemble with the proper sealant (Hondabond Silver or Threebond) on the case halves, and new gaskets throughout ......

YES, I am discussing a total engine tear-down to bare cases both top and bottom ends.....You MAY not have to go quite THAT far, but won't know until you open her up and inspect.....
 

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If there's blobs of sealnt on the outside I'll guarantee there's some on the inside. The sealant is applied as a VERY thin smear to the surfaces since it's only sealing the slight machining imperfections.
 
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