Crankcase sealant

[Little Jerrry]

Hi

Just hoping to get some clarification - I have a paper/cork gasket for a stihl 031av crankcase that I am rebuilding - if I use threebond 1104/ yamabond sealant, do I use that in conjuction with the gasket or does it replace the gasket all together?

Also would this yamabond product be suitable for sealing the fuel tank section on an 031av as I dont have a gasket for that - i bought gasket paper to make one but it may not be necessary.

Regards

Adam

 

[Little Jerrry]

Also, I have the bearings on the crankshaft as they do not need replacing....is it easier to take them off and put the bearings in the case by themselves like in the stihl manual and then put on the crankshaft, or should I just install the bearings and crank as one into the case?

 

[hotshot]

No sealant is required on the CC or the fuel tank gaskets. You will need an OEM case gasket in there, or the same thickness as OEM.

The methods for installing bearings can go either way, search & read the many great posts here. Suggest to follow the Stihl service manual.

It’s best to have the right tools or have a saw shop with the correct tools do it, for just your one saw.

I pull the bearings off the crank with a splitter, heat up the cases to 275F in the oven, and then literally drop the bearings in.

Then (cold) install the crankshaft into the halves’ inner bearing races with a hydraulic press or a special puller tool & squared off pipe sleeves.

If you don’t have a shop press, you could jerry rig it and use stacked washers & cut pipe spacers, and the saws clutch hub & FW nut, as long as the spacers are pushing against the bearing INNER races.

 

[blsnelling]

Do not leave out the case gasket. There may not be sufficient width in the case if you do.

 

[Chiknhawk]

Yamabond/hondabond is great stuff but its purpose is a machine fit sealant on metal to metal surfaces the japs do it right machine fit and use bond to seal is they to go as for you listen to the others in this thread use the gaskets or u will regret it good luck

Sent from my SM-N960U using Tapatalk

 

[Little Jerrry]

Thanks guys for clearing that up....

I'll just follow the manual and take the bearings off, I have all the tools although a hydraulic press on a chainsaw crankshaft makes me a little nervous...hopefully heating up the bearings / freezing the crank will be enough. I just re-powdercoated everything so a little nervous too about putting too much heat on my nicely restored casing.