Reasembly-crankcases

Will be reassembling the bottom end of my WR450 in the next few days, if the parts get here!

Went to my local Yamaha dealer to get some case sealant and asked for Yamabond #4 and the guy said he'd never heard of it!!!!:)

So he sold me some ThreeBond 1215 to do the same job!

I read the specs on it and it says its a silicone based gasket material for thicker filling requirements!

Sounds a bit dodgy to be using on case halves!

Any one here know for sure if its safe to use...:D

It's likely fine, I used Motoseal by permatex on my WR cases, worked perfect - just as a comparison, the Motoseal was quite runny - does not build up very thick at all.

It will be fine, I'm not sure it isn't the same stuff in a different tube.

+2 on the threebond.

i work for a yamaha dealer the no longer make yamabond 4 witch makes me angery but we now use the threebond product ourselves and it works fine

Threebond is all I use to seal cases I use 1211,excellent stuff,Threebond is definetly the way to go.I use no other sealant!! Check out that number on there website and see if it is the correct application.

When I worked at a Chevy dealer, I had available to me several sealants that are frankly superior to anything commercially sold at stores. There were a couple in particular that were formulated specifically for sealing machined aluminum cases without gaskets that absolutely rocked, but they are extraordinarily expensive when bought over the counter.

Threebond is a good product for the purpose, though.

ive had good luck with hondabond. its really expensive though

Threebond is all I use to seal cases I use 1211,excellent stuff,Threebond is definetly the way to go.I use no other sealant!! Check out that number on there website and see if it is the correct application.

Yeah bigred I think that No. "1211" is the right stuff, after reading some of their product specs!!!

Or it's at least better stuff:excuseme:

Yeah bigred I think that No. "1211" is the right stuff, after reading some of their product specs!!!

Or it's at least better stuff:excuseme:

Na you are fine with the 1215,the viscosity is just a little thicker,it will probably set up quicker. You are probably better off with the 1215,it is gray in color, match your cases better. Do not put globs of this stuff on your cases,a nice thin layer spread. If you over do it you will have extra silicone clogging lubrication points where oil needs to feed.YOU ARE FINE WITH THE 1215:thumbsup:

With any RTV sealant, surface prep is the key to success.

Before putting any parts into the cases, lightly sand the joint surface. Your purpose is only to add some "tooth" to the surface, not to remove any material. This will give the sealer a better bite, and help keep it from slipping on the surface later on.

Just prior to making the assembly, remove ALL oil and residue from the cases and be sure none will drip across the joint while assembling it. Use a commercial brake parts or electrical contact cleaner for this. Carb cleaners leave too much behind them, and can ruin the seal. The better products are more tolerant of oil and poor prep than others, but none of them work their best unless set up right.

I've had great success using the non chlorine brake cleaners available - they seem to be less harmful to rubber as well - although there shouldn't be more than a few removable o-rings nearby.

Very informative, thanks guy's!!! :)

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