Stihl 028 Sealant, gasket, or both

[WoodFeller]

Hello to all chainsaw fixers. I am working on a Stihl 028av with 44mm piston When I disassembled it I found gaskets in there. So for that reason, I ordered some OEM replacements. I have read some threads in here about not using gaskets for reassembly, but instead just using the Dirko HT or equivalent on the case halves and the jug base. Because this particular saw had gaskets in there, I am thinking I should put the crankcase gasket back in so I don't change the crank side to side clearance. I am thinking the thickness of it was figured in on the original build design. Can I apply a very thin coat of Dirko HT to the gasket for more positive sealing? Also, I ordered a Meteor Jug and piston assembly upgrade to super (Baileys part # MCA CC2427) (46mm), and now that the top end is not OEM anymore, should I install the stock jug base gasket in there ? I ordered the stock 0.5mm thick jug gasket part #1118 029 2306. Would that be the right gasket to use with the Meteor jug without getting too involved with squish factors? I know i'm asking 4 different questions here, can you please help me to understand the best way to reassemble for a lasting rebuild?
Thanks so much

 

[farmer steve]

bump.

 

[pioneerguy600]

Do use a gasket on the case halves, no sealant but both case halves need to be thoroughly clean and dry on assembly.
The squish would need to be measured on any aftermarket replacement on this saw, if you can`t or don`t want to measure squish then err on the side of caution and use a cylinder base gasket. Aftermarket parts are not always exactly the same tolerances that OEM parts are, therefore only measuring the actual squish would be necessary. Either gasket would be fine but almost certain the thinner gasket would provide enough squish clearance even with an aftermarket P&C set.

 

[HarleyT]

You have been reading posts about different engine styles, one is what these guys call a "clamshell" engine.
On these the bottom engine cap uses sealant.

 

[bmwpowere36m3]

On a split crankcase definitely use a gasket if there was one originally... some add a bit of dressing, RTV or anaerobic for additional insurance. Cylinder base gasket will affect squish, so care must be taken if you plan to delete it (measure squish and insure its sufficient). Just like the crankcase, some added a bit of "dressing" to the base gasket. If you delete it, then you definitely need a sealant.

I would prefer using more of a gasket dressing than a sealant/gasket maker on gaskets. If both surfaces are clean, smooth and oil-free, then you really shouldn't need anything other the gasket (factory doesn't apply anything). Either way, apply very sparingly.

 

[pioneerguy600]

One reason I don`t condone using a sealant on crankcase gaskets is that many types are not oil and gas resistant I and have seen instances where the sealant has degraded leaving the cases loose and allowing air to get into the crankcase. If the sealant is of a known good type for fuel and oil exposure as the bottom of a chainsaw crankcase is always wet with both then it would be ok to dress it with a very thin layer before re assembly. Most RTV sealants are not worth crap on these cases and its the one I see used most often on failed installations. Clean dry but smooth mating surfaces on the cases will seal perfectly with the correct gaskets but buyer beware of the cheap AM crankcase gaskets, many are not made of the correct type of material and disintegrate in short order.