89 yamaha v4 115

[justinspot]

Any one have any idea what type of metal yamaha uses for head bolts . Its shinny with a 8 on top . I think its just zinc plated . Dont believe stainless grades bolt like that and chrome likes to flake . Any help would be good . I would use oem but its at least 3 weeks out to maybe get them .

 

[ClassicAQ]

Stainless steel. The number 8 refers to its metric size. If the bolt is shiny like zinc then I recon the previous owner installed it. Not a good idea. There are a number of yamaha distributors to order from that deliver in 3-5 days. Head bolts are a common part stocked by authorized yamaha service centers. Find one local to you, call and ask them if they have it in stock.

 

[justinspot]

Appreciate the response but I have to disagree . The bolts are stock and not stainless . The 8 doesn't mean size cause all the bolts say 8 and there are 3 main sizes . If they are stainless they are poor quality cause how magnetic they are

 

[justinspot]

so i guess i owe an apology . They are stainless . but with the torque only being 22ft lbs , what grade should i go with . the bolt is a m8 x 60 mm stretch to yield

 

[ClassicAQ]

so i guess i owe an apology . They are stainless . but with the torque only being 22ft lbs , what grade should i go with . the bolt is a m8 x 60 mm stretch to yield

When I said 8 refers to metric size I should have indicated M8, not implying 8mm. M8=12mm. Cylinder head bolts have specified two step torque of 11ft/lb and 22ft/lb. Cylinder head cover bolts have specified two step torque of 2.9ft/lb and 5.8ft/lb. I'm not sure what you mean by "grade" you should go with. If you're speaking of the bolt, the grade of SS isn't a choice you have so long as you use a yamaha oem head bolt specific to your engine. If you're intending on using a non-yamaha oem bolt I highly recommend not doing so. There are some parts that don't need to be replaced with yamaha oem. Then there are very important parts that should, like head bolts. About $2/bolt. Otherwise, you'll be installing a untested torque, standard bolt into threads that undergo high heat as well as subjected to a corrosive environment. It's not a good idea. As I mentioned in my previous...go to your local yamaha parts dealer. Good chance they'll have your size head bolt in stock. If not, order it online and wait a few days for delivery.

 

[justinspot]

When I said 8 refers to metric size I should have indicated M8, not implying 8mm. M8=12mm. Cylinder head bolts have specified two step torque of 11ft/lb and 22ft/lb. Cylinder head cover bolts have specified two step torque of 2.9ft/lb and 5.8ft/lb. I'm not sure what you mean by "grade" you should go with. If you're speaking of the bolt, the grade of SS isn't a choice you have so long as you use a yamaha oem head bolt specific to your engine. If you're intending on using a non-yamaha oem bolt I highly recommend not doing so. There are some parts that don't need to be replaced with yamaha oem. Then there are very important parts that should, like head bolts. About $2/bolt. Otherwise, you'll be installing a untested torque, standard bolt into threads that undergo high heat as well as subjected to a corrosive environment. It's not a good idea. As I mentioned in my previous...go to your local yamaha parts dealer. Good chance they'll have your size head bolt in stock. If not, order it online and wait a few days for delivery.

Thank you