3120 oil side crank seal.

[MattyF]

Never done one and believe it’s similar to the old 61 266 set ups ,any way it a very different set up to what I’m used too, looks like the crank case oil seal is part of the oil pump? Are they easy to fit or are special tools needed, would you fit the oil pump then press the seal in ?

Also there is some sort of sealant used which I have no idea what it is around the oil pump.

Lastly there is this which looks like some thing has gone wrong as it bears no resemblance to what it should be in the parts diagram! What should it be ?

[adw]

You need to fit the seal in the pump off the saw, there should be no sealant around the pup, i have no idea what the hell that is, clean it off. Be very careful re fitting the pump as the step on the crank will flip the spring out the back of the seal, there is a special sleeve to fit on the crank to take the seal over the step,you could use some insulating tape on the crank to ease the seal over the step, grease the o ring well before fitting, make sure the oil pump cable fits back into the slot in the crankcase

[adw]

Just remembered what that is on the pump, it is/was a foam pad to keep the dirt out of the back of the pump shaft, looks like it has started to dissolve.

[MattyF]

Aye I think the foam has dissolved and jammed up the cable as I could never get that to work.
Cheers Andrew ! I think I may order a new assembly as well as fly wheel, then I know the whole lot is good.

[CallumA]

Don't want to hijack te thread but milling with a 3120xp and the flywheel bearing cage failed causing damage to the piston! Should I run the saw at 40:1 as the flywheel bearing will always see less oil! Or just rebuild and crack on!!

[Haironyourchest]

5 hours ago, CallumA said:

Don't want to hijack te thread but milling with a 3120xp and the flywheel bearing cage failed causing damage to the piston! Should I run the saw at 40:1 as the flywheel bearing will always see less oil! Or just rebuild and crack on!!

You should. Especially when milling. And tune rich.