Carbie inlet sealant

[Rosco86]

Have the half inch fibre  sealing plate on my CCM motor and just wondering what people use to seal the plate to the motor and then the inlet tract to the plate. Want something that seals obviously but doesn't destroy/ is able to be removed when the motor needs to be rebuilt.
Rosco 86

[FourstrokeForever]

Any of the good silicon gasket sealers will do the job Rosco. Personally I use the red high temp stuff for fuel and exhaust sealer.

[sleepy]

Silicons aren't the best choise where there is raw fuel as it eats into it. Best is Loctite 515 which is fuel proof.

[Mike52]

Yamaha 3bond.

[Momus]

Yeah, 515 Loctite. It looks like raspberry jam and is very effective.

[sleepy]

Raspberry jam!!! I'll have to put some on my toast in the morning and see how it tastes.

[grouty]

I have always had issues with the sealing of the flange mount Amal Mk1's on my CCM. I have found over the years that a very thin smear of Golden Hermetite to the gaskets when assembling works well. I also had issues with the nuts coming loose on the carb. I have used aircraft spec K-nuts for several years now without any further problems.

Make sure you check all the sealing faces are flat (including the fibre).

[Momus]

K nuts are very nice; unfortunately mostly in unf thread.  I've made several intake manifold stubs lately and where room used an O ring housed in the flange as the seal.

[Mick D]

I reckon these two fellas are spot on,

Silicons aren't the best choise where there is raw fuel as it eats into it. Best is Loctite 515 which is fuel proof.

Another +1 for 515, good gear, and the 518 is high temp.
Cheers Al.

I have balanced and harmonised a couple of scary fast Mercury Formula outboards, just about to do another.  Cosworth cast 72deg V6 two stroke block. Metal to metal on the axially split crank cases(Loctite).

Use to hang with boys that burnt the midnight oil preparing Michael Guest's National Evo4 Lancer. They were always Brainstorming for solutions and improvements etc. Transmission always leaking or weeping. Identified cause; shearing/delaminating gaskets because cases were flexing under load. Solution; discard gaskets, run metal to metal joints with loctite 518 instead. No Gaskets = less movement in joint. End of leaks and weeps.

I just pulled apart a Maico reed box last week. It had an air leak. It had several gaskets and metal spacers in it. It had been assembled with Red silicon, which had broke down and failed(from the fuel or oil I was left guessing?). The very next word my mind said when I read Sleepy's first post was "Eureka"

[Rosco86]

Thanks everyone I'm always impressed how much knowledge and sensible approaches are generated on this forum.
Rosco86

[Mick D]

I used to use Permatex #3 Non-Hardening Aviation as my staple.
One of the reasons that I went to Loctite is because it is heaps easier and quicker to clean off to go again next time. Also if quality gasket material is used, Loctite in most cases will usually let go and separate itself with a couple of gentle shocks without delaminating the gasket.
But definitely, I have never had a failure with the Permatex Aviation #3 on an inlet joint and it is dirt cheap at Super Cheap    

[Jumbo J]

I have balanced and harmonised a couple of scary fast Mercury Formula outboards, just about to do another.  Cosworth cast 72deg V6 two stroke block. Metal to metal on the axially split crank cases.

Use to hang with boys that burnt the midnight oil preparing Michael Guests National Evo4 Lancer. They were always Brainstorming for solutions and improvements etc. Transmission always leaking or weeping. Identified cause; shearing/delaminating gaskets because cases were flexing under load. Solution; discard gaskets, run metal to metal joints with loctite 518 instead. No Gaskets = less movement in joint. End of leaks and weeps.

I just pulled apart a Maico reed box last week. It had an air leak. It had several gaskets and metal spacers in it. It had been assembled with Red silicon, which had broke down and failed(from the fuel or oil I was left guessing?). The next word my mind said when I read Sleepy's first post was "Eureka"
[/quote]

Ive used 3Bond before and its a bit of a nightmare to get off when disassembling. Is Locktite  easy to remove after its been on for a while esp in area's that generate heat, like rocker boxes, inlet and exhaust manifolds?

[Mick D]

Yes Jumbo, I HATE three bond for that reason Time is money and a previous three bond aplication becomes an anti christ if trying to do a quick track repair or tune.

Used it once, then threw the rest out. HATE it with a passion.
Mind you, it certainly does seal if you can get the joint together before it cures
What a prick to get off though

[LWC82PE]

+1 for the Loctite 515. I also think Threebond 1215 is great stuff for engine cases, rocker boxes/covers etc. I seem to be lately getting bikes in that have have had the engines recently rebuilt by other people that leak oil everywhere because they have used poor or wrong for the application gasket sealants. I then rebuild them with combination of Threebond/Loctite/Hylomar then there's no more leaks. It also pays to check out the gasket surfaces for imperfections too. I have seen some shocking stuff lately.
Be careful not to tighten the Amal flange mount nuts too tight. Its easy to distort the bodies and then end up with sticking slide issues.

[Mick D]

It also pays to check out the gasket surfaces for imperfections too. I have seen some shocking stuff lately.

Just like putting your socks on before your shoes.
Yeap, I lot of horrible mutilation out there.
One of my pet hates, why would any one think a screw driver or chisel across a sealing joint be the way to separate components unbef&^%$lievable. Then over tighten on the raised mushroom part of their gouge and bend the crap out of the base flange? Why have so many Mothers had them?

Its awesome to have a friend with a great work shop though

[yamaico]

I have used loctite sealer for over thirty years and never had a failure. In addition to crankcases I use it on crank seals - they are a bit slippery to get in sometimes but once cured do not move. The beauty of loctite, in my humble opinion, is that it is anaerobic, and therefore any excess just washes away - not the case with Yamabond type sealers, as evidenced on just about every Yamaha produced. The loctite can be simply cleaned off with acetone at rebuild time, not scraped off like the others.

[Digga]

This might be helpful 

http://www.loctite.com.au/gasketing-4055.htm
http://www.henkel.com.au/aue/content_data/283618_gasketing.pdf

Key things to remember are that for larger gaps (> 0.5mm) then typically a silicon or similar type sealant is required, for lesser gaps then an anaerobic sealant (cures in the absence of oxygen)should be used. Remembering that all flange surfaces must be clean, smooth, dry & (0.0 - 0.5 mm), although in industry we typically would use 0.25 mm as the cut off gap for surface roughness.

L515, L518 are very commonly used but if you are looking for a more flexible version then L5188 is also a good choice.