Let me share something I found out today. I bought a generic complete gasket set for my XT 600 for = $37 at the wholesaler. I only needed the clutch and flywheel cover gaskets but they are =$40 for the two OEM. The brand is NE Brand Super Gasket which has some funny Chinglish on the package: "Special Qualification of Materials. Special Chemical & mixture have been treated to the gasket materials in order to withstand high pressure and oil resistance apply of any engine fluid (gum) shellac compound are not required use material". It looks like this one:
When I stopped by the local Yamaha dealer to pick up a kickstarter seal and oil valve I noticed they had the same gaskets for sale for 25% more. I asked the workshop manager and he said they use them all the time and they are fine. He said without them rebuilding some motors would not be viable given our weak currency and the strong Yen. He also said if your surfaces are smooth and flush no sealant is necessary. This is debated elsewhere by "experts" (see below) but this comes from the horse's mouth. Motorbikes, in my view, should be cheap to run and maintain but if you are rich and fussy and prefer investing in Japan rather than China or Taiwan, by all means buy OEM.
Each to their own. Even dealers can't agree. I bought a used Honda XR125 for our youngest. I prefer the Yamaha brand since they support their old bikes with spares unlike Honda and some others but I picked it up for a song from a kid who has outgrown it. It is actually old wine in a new bottle. It's 70s technology with a CG125 pushrod motor. I rang the dealer where it was serviced to ask what oil they used. They said Castrol Actevo semi-synthetic motorcycle oil. When I went to our local dealer to pick up some spares their manager said he has been in the game for 30 years and in this old school motor they use Castrol GTX 20w-50. It is half the price so cheap me went with the local guy and bought a 5l which I used in my Tenere. There is a bike shop in town that uses GTX in all four stroke bikes and has mechanics who have been in the game for decades and worked at the dealerships.
Anyhow it shows that even the professionals don't agree. Me I'll avoid the tolls and go the cheapest recommended route every time.
Hmmm, interesting write up here from a guy who put a 101mm big bore kit in his SRX. I wouldn't wish this mission to get things working on even my enemies!
And he was using the gaskets provided by Wiseco from what I gathered - Serco Engineering Gaskets.
This was the provider of a good head gasket... "He has, however supplied the details for a mob in Eagle Farm who make gaskets. We contacted them immediately, and yes, they will be making my new copper annealed head-gasket for me for the very reasonable sum of $120. "
That's your neck of the woods Mezo. Would you know who he's talking about?
Very interesting. And at $33.00US not too pricey at all. Out of curiousity, why did Yamaha not go standard with straight copper gaskets as per that link. Are there downfalls to a copper gasket?
Also, I'm assuming that 2mm oversize over a 98mm bore/piston is ok?