Engine case sealant

Threebond makes Hondabond, Yamabond, Kawabond, and Suzukibond.

Some are RTV and others acrylic adhesive. Both high quality, but it's the acrylic adhesive that's earned all the ***bond love. That's why I recommended the 1184. That's the latest formula. If you walk into a Honda dealer and ask for Hondabond, they may hand you a tube of RTV.
 
Also do a lot of volvo work. The upper cam retainer uses a pink roll on stuff. No idea what it is . Its applied with a foam roller. Really thin stuff. Again application is key like anything.
 
The problem with any RTV, motorcycles have much smaller oil passages to camshaft and feed gearbox bearings/clutch.
RTV can and does, 'string' break off and block oil passages.
I generally use Threebond 1104, a non setting gasket sealer but I hear it's had a name change?
I've also used Blue Hylomar for years, it was developed by Rolls Royce and is also 'non setting'.
The idea of non setting sealers is, any that does drip into sump tends to stay there.
If it gets to oil pump, it smears incredibly thin, doesn't damage anything.
That doesn't happen with RTV as it 'strings' and does go through oil pump usually blocking oil feed to OHC/DOHC
In the past (1970's) I used RTV as I didn't know any better.
Never had a cam bearing failure but oil pump pick up usually had a few bits in strainer even though I was very careful not to apply more than needed.
I would never recommend RTV in any engine unless absolutely necessary (some area's on V-8's, corners of intake manifolds, etc)
As I have 50+ years experience building and modifying motorcycle engines (including in dealerships), I have seen the problems with RTV first hand on many many bikes and wouldn't use it on even a leaky old Triumph (and I worked at a Honda/Yamaha/Triumph dealer in late 70's)
 
One of the important things is gasoline resistance. For things like case halves on 2 strokes which are always in contact with fuel. many RTV's fall short. Threebond Yamabond Hondabond all seem to work well. I have the old number 2 Permatex and the only time it failed completely was a 2 piece McCulloch chainsaw fuel tank. Although not aproved for it i had just replaced a windshield using DOW U-428 urethane. I thought why not and used it on the 2 piece fuel tank gave it overnight before fueling up the saw, been 5 years at least and not a drop of leakage.
Stihl still recommends Dirko HT for their case halves, yet Dirko is not specifically rated for fuel contact.
 
crazypj said:
RTV can and does, 'string' break off and block oil passages.
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^^THIS. I’d always been skeptical of RTV but taking apart an engine that had copious amounts of that orange RTV that was supposedly the recommended stuff for GM products and it was leaking everywhere nailed it for me. But when I pulled the pan and there were strings all over the oil pump pickup screen I was horrified. I don’t remember all the specifics what led up to the tear down but I’ve never seen any RTV that sticks after being exposed to oil and several heat cycles like my old school aero seal. But I’ll admit I’ve never heard of these other non setting sealers much less try them.
 
C-Bag said:
^^THIS. I’d always been skeptical of RTV but taking apart an engine that had copious amounts of that orange RTV that was supposedly the recommended stuff for GM products and it was leaking everywhere nailed it for me. But when I pulled the pan and there were strings all over the oil pump pickup screen I was horrified. I don’t remember all the specifics what led up to the tear down but I’ve never seen any RTV that sticks after being exposed to oil and several heat cycles like my old school aero seal. But I’ll admit I’ve never heard of these other non setting sealers much less try them.
Click to expand...
Exactly as crazypj stated. Who ever assembled this bike 40 years ago went "crazy with the cheese wiz". Sheet was freakin everywhere. Oil pump suction screen 75% plugged. (no pic) I don't think; Honda, yama or Threebond was available then. New products have come along way since
 

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