sealant

[crosbyman]

check utubes tons of them to show you …  inbed the spagetti in the goo to hold it in place.  work  goo around  bolt holes      had  goo  under  bolt heads and on threads

 

when done do a pressure-vacum  test  for 10 minutes

cut spagetti 90 degrees   against  the  rear  Gearcase Head Assembly

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[crosbyman]

if you download the  Johnson bible  all you need to know about oldies in there  magneto  carbs  GC  timing …everything !!

$20  for a 400 page + bible     print locally  spring bound with plastic cover sheets  🙂

https://watercraftmanuals.com/outboard/johnson/manuals/johnson-302231.htm

 

that pict. on spagetti  commes from that manual

 

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bfitz241, aquasonic

[fleetwin]

While the 847typeM sealer is a great sealer, it is truly tough to work with and dries super quick.  I wish they would package the stuff in smaller tubes.  The OMC gel seal (or 3M equivalent) is much easier to work with, but requires proper prep or it won’t seal properly.  I wouldn’t use just any sealer for this job, it is a super important process that is easily messed up.  Imagine firing up a freshly rebuilt powerhead only to see bubbles coming out of the crankcase halves….Now the engine has to be split apart again.  Once again, the prep is the real important factor here.  If the halves are not properly cleaned/prepped, the block halves will be “shimmed apart” just slightly creating crankcase leaks.  It might be a good idea to bolt the crankcase halves together “dry” before assembly and check the various flanges for fit with a small feeler gage.

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bfitz241

[aquasonic]

Here’s the “spaghetti seal” that I ordered from Grainger and have used successfully.

Std, Black, Buna-N Round Cord – 6VFC3|ZUSA-RC-875 – Grainger

There are now two options listed as a rounded 3/32″ diameter or cross section. This one is 0.093″ and the other option is 0.103″. I doubt that the 0.01″ really makes much of a difference. There is a little extra room in the gearcase groove, and the seal gets flattened a bit upon tightening the screws.

I’ll stick with the 0.093″ as seen in the link because I know that it works. This is the “general purpose” option with a medium durometer value (hardness) of 70A.

 

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bfitz241

[crosbyman]

personnaly having used .103  I figured it would actually help compensate slight wrapping in the mating halves.  it certainly held well undr   a pressure/vacum test

Joining AOMCI has priviledges 🙂

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aquasonic

[bfitz241]

thanks for all the help/

I pressurized the gearcase and stuck it in a bucket before I take it apart.  Prop seal leaks and the forward screw on the left side leaks very badly.  I guess that’s my starting point

 

[fleetwin]

fleetwin wrote:

While the 847typeM sealer is a great sealer, it is truly tough to work with and dries super quick.  I wish they would package the stuff in smaller tubes.  The OMC gel seal (or 3M equivalent) is much easier to work with, but requires proper prep or it won’t seal properly.  I wouldn’t use just any sealer for this job, it is a super important process that is easily messed up.  Imagine firing up a freshly rebuilt powerhead only to see bubbles coming out of the crankcase halves….Now the engine has to be split apart again.  Once again, the prep is the real important factor here.  If the halves are not properly cleaned/prepped, the block halves will be “shimmed apart” just slightly creating crankcase leaks.  It might be a good idea to bolt the crankcase halves together “dry” before assembly and check the various flanges for fit with a small feeler gage.

Please forgive me, don’t think I read the original post carefully, thought it referred to sealing crankcase halves…..  Seems like we are speaking about clamshell split gearcases…

In that case, my response was partially in error.  Never use OMC gel seal on clamshell/split gearcases!

The beauty of the 847 sealer in this application is that it is strong and dries quickly.  Keep in mind that the sealer helps keep the spaghetti seal in place during reassembly.  In this case, unlike crankcase sealing, it is helpful to lay a very thin bead (yeah I know, tough to do) in the spaghetti seal groove, then quickly install the spaghetti seal and let it dry in place before trimming the ends.  The spaghetti seal loves to pop out of the groove, especially during installation.   Again, it would be so helpful if they packaged this stuff in smaller tubes making it easier to apply without making a big mess.

I laugh when folks claim that sealing up one of these split gearcase is relatively simple, HA-HA!  Sure, most can probably get it back together ok, but sealed up properly, well that is another story.  And god forbid you find a leak during pressure testing after assembly, now you must pull it all apart and spend considerable time cleaning out that darn 847 sealer that works so well!

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bob-d

[jeff-register]

Be sure your motor has no water in the tower assembly before turbing it upside down. It will get water into the powerhead. What ever sealer  you use blean the mating surfaces with acetone to insure a super bond, OMC motors I install the shift shaft on the o ring to avoid ripping the o ring  with the threads, then install the brass keeperthen the pressure in the o ring can be regulated plus a light film of inert lube to avoidany extra friction.

Just the way I did it.

[bfitz241]

To close this out:

Used a Sierra kit and ultra black.   Worked really well.  Gearcase sealed up tight but I found another problem that I’ll put in another thread since it’s different subject matter.

 

[jeff-register]

Great,

I have found many compound problems on everything, good luck!!

[Author]

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