Sump plate Bolts?

[SPEIRMOOR]

Of course I snapped on one by not paying attention to the torque settings in the manual.Does anyone know what size these are? I searched Mikesxs but couldnt find anywhere.I think they are M6 but if I know the length I can get them from McMasterCarr.

 

[jayel]

bolts are M6x25

 

[5twins]

But they're special, designed to break off if you over tighten them instead of stripping the hole. If you switch to a normal bolt, use a torque wrench and don't exceed 6 to 7 ft/lbs.

 

[estcstm3]

Hi 5t - Not to revive an old thread but do you know where to get replacement bolts? Mine are stretched to all hell. Or is my only option to get the M6x25?

I couldn't find the part on boats.net under crankcase as a reference?

 

[5twins]

The bolts are listed on the oil pump diagram but it also says they're not available any more. I guess a standard M6 x 25 is your only option. I switched to stainless bolts on mine.

http://www.boats.net/parts/search/Yamaha/Motorcycle/1982/XS650SJ/OIL PUMP/parts.html

 

[estcstm3]

You are right. So did you just replace is hardware stainless steel M6x25?

 

[5twins]

Yes, just the cheaper 18-8 stainless bolts.

 

[gggGary]

Switch to phillips pan heads that'll keep em from overtorquing.

 

[estcstm3]

Okay so I picked up some m6 and realized they have a different collar. The original had a smooth collar above the threads, while the new ones are threads the whole way......

Does this make a difference?

 

[fredintoon]

Switch to phillips pan heads that'll keep em from overtorquing.

Hi Gary,
for shame.
Phillips heads are designed to "cam out" to limit the installation torque on sheet metal screws.
Which makes them the worst possible choice for holding on anything that has to come off again.
Persons too cheap to buy a torque wrench and too clumsy to work without one should switch to Allen head screws and only tighten them with a short Allen key.

 

[estcstm3]

back to my question. Does it matter that my replacement bolts are threaded the whole way down? See pic two posts up.

 

[5twins]

No, threads all the way won't hurt. Finding partially threaded bolts like your originals that short (25mm) would be difficult, but no need to.

 

[estcstm3]

Thanks again 5T. I feel like you have been over my shoulder helping me through this #4 starter gear, drag clip replacement job. I should be able to finish everything up this weekend. I ended up ordering a nice CDI torque wrench that should be here sat afternoon.

 

[fredintoon]

back to my question. Does it matter that my replacement bolts are threaded the whole way down? See pic two posts up.

Hi estcstm3,
both those bolts have rolled threads so their shank diameters are smaller than their thread diameters.
So the original bolts couldn't have used their plain shanks to locate the sump plate so yeah, the replacement minimal shank bolts will work just as well.

 

[5twins]

I've been running the stainless ones I mentioned for years with no problems. There was nothing structurally wrong with my originals, they were just rusting on the heads. Hanging off the bottom of the motor like they do, basically the road debris and grit sand blasted the cad plating off (or whatever type of plating was on there). I figured stainless would be the best option to avoid that in the future. I always use a torque wrench and always anti-seize the threads so I'm not worried about the possible difference in strength and the non-break away nature of the replacements.

 

[estcstm3]

I stopped by a local bike shop, been around along time..... he said absolutely no problem using the SS M6, just not to over torque =).

Consider my question resolved. Thanks guys!

 

[gggGary]

Hi Gary,
for shame.
Phillips heads are designed to "cam out" to limit the installation torque on sheet metal screws.
Which makes them the worst possible choice for holding on anything that has to come off again.
Persons too cheap to buy a torque wrench and too clumsy to work without one......

I think you got my point

 

[smirge]

I broke off a bolt on my 79 xs650 and ordered these from amazon to replace. Aluminum M6x25 allen head bolts. http://www.amazon.com/gp/product/B00AA3CIK2/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

Think they'll be a problem?

The torque wrench i was using was 0-600 inch pounds and I was eyeballing it to get just under 100 for these bolts when one broke. I plan on using this 6Nm wrench
http://www.amazon.com/gp/product/B004XG5YJO/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

to make sure i don't overtighten this time.

 

[hard_y_rd]

Probably opening a can of worms here but when using a smaller diameter stainless bolt in aluminum, anti seize should be applied on the threads. Aluminum and stainless react badly in moist climates without protection, they almost bond together. When comes time to take them out they shear off.

 

[angus67]

I've been running the stainless ones I mentioned for years with no problems. There was nothing structurally wrong with my originals, they were just rusting on the heads. Hanging off the bottom of the motor like they do, basically the road debris and grit sand blasted the cad plating off (or whatever type of plating was on there). I figured stainless would be the best option to avoid that in the future. I always use a torque wrench and always anti-seize the threads so I'm not worried about the possible difference in strength and the non-break away nature of the replacements.

Do you meen like 5t did?