Stainless Side Cover Bolts

[NewToXs]

I'm going to pull both side covers off my motor shortly to replace sprockets, clutch shaft seal and the clutch. I'm contemplating ordering some stainless socket head allen screws to replace all the dingy and rusting bolts.

Has anyone had any concerns with stainless fasteners galling the threads of the engine case?

I've had issues before but its generally only on a stainless to stainless interface. I would think it wouldn't be much of a concern with the aluminum threads of the engine case.

 

[Jim]

I always replace sidecover fasteners with stainless. A dab of grease goes a long way against galling for any fastener.
Bolt Depot (.com) has the best prices for stainless allens I've run across.

 

[toglhot]

There's always lots of noise over dissimilar metals - stainless/aluminium. what everyone forgets is the original fasteners are zinc coated mild steel, they are pretty dissimilar to aluminium and will react with the aluminium given the right conditions. look at the picture, I've never had stainless react with aluminium like this. in short stainless socket heads are way better that zinc coated, mild steel, JIS screws. I've used stainless socket heads on pretty well every bike I've ever had, never had a problem. You can buy kits, but it's a lot cheaper to measure your existing screws and buy them individually.

 

[5twins]

I use the original screws. I clean them up well and paint the heads black. I like the contrast of the black heads to the polished cases. I liberally coat the screws with anti-seize, the whole length not just the threads. That solves the dissimilar metal and corrosion issue. I do use some stainless buttonhead Allens though, on the big round alternator cover and on the points/advance housing covers. These also get the anti-seize treatment .....

Just one little thing I'll mention here - Yamaha cheaped out on the alternator cover screws, using ones that were too short. If replacing, best to get some that are slightly longer .....