Saving a 1980 750 twin.

Thanks guys!
Jbosh - my buddy has a stand alone buffer with two wheels and a ton of different polishes. I once polished a set of fork lowers by hand and I watched all five die hard movies. I polished a set of lowers the other day and it took me 30 minutes on the buffer. Its quick work on that thing, although its not to be underestimated. I was polishing the tube that i capped the swing arm with, and at one point i blinked and the tube disappeared from my hands. two seconds later i heard it bouncing out the front door. lol

Im trying to find some bolts for my close tolerance motor mounts. Stock is M10. I was going to go with M11 to remove the slop but those are near impossible to find so decided to go to 7/16 (11.11mm) and can't find anything over 6" in length. Would M12 be too much over? there are long M12 bolts out there but they usually come in packs of 25 and cost big money.

I'm thinking about buying some 304 or 316 stainless rod, cutting thread and welding a stainless flange nut on the end. My only concern is that this wont be strong enough. Ideally i would like grade 8.8 or higher but im having no luck

suggestions?

Call a couple local machine shops. They might be able to build exactly what you need heat treated and everything. It will be custom and might not be more than your bag of bolts. If anything they can point you to or order from some industry vendors that don't regularly sell retail.

I have a Pingle engine mount kit on my 1000b project. The long bolts in that kit should be close to the correct length. If they are give Pingle a call they may sell you just the parts you need.

GPzMOD750 wrote: Call a couple local machine shops. They might be able to build exactly what you need heat treated and everything. It will be custom and might not be more than your bag of bolts. If anything they can point you to or order from some industry vendors that don't regularly sell retail.

I was going to call a guy that has done some excellent machining for me before and see what he has to say about the situation on monday. the problem is if i have him make them out of hardened steel I have to figure out to coat them so they don't rust. The problem with bolts like these is the industrial vendors want to sell you 250 of them at a time.

80B4 wrote: I have a Pingle engine mount kit on my 1000b project. The long bolts in that kit should be close to the correct length. If they are give Pingle a call they may sell you just the parts you need.

HA! great minds think alike. I have the pingle motor mount kit for my 1000 as well, and pulled it out to see if the bolts were the same. the longest bolt is pretty much the same length, but it is just some rod they welded a nut to like i described. the second longest one is too long.these are the only bolts I cannot find. I did some reading on the tensile strength of 316 and i think it might be adequate if i don't weld and use good nuts on the ends. Ill have to get a good die though.
the longest bolt passes through the engine when you could just bolt it on either side separately. but i would like it all the way through if i could.

I think those long bolts in the Pingle kit are high strength tool steel. I spoke to my machinest consultant and he said A2 is what he would use. Heat treated and it's done. I've also been thinking that 4130 is also a good way to go. It's not expensive and it's easy to work. McMaster.com has both in the imperial sizes needed to duplicate the Pingle kit. They also sell the reams that are needed to install.
Thanks for working on this, I'll use the information on my twin.

There's heat treatable stainless as well.

So i bought two alloys to try. 4340 chromoly which is on par with grade 8 bolts. and I bought some 17-4 stainless which is a precipitation hardnened alloy. Just so happens I have this....



Also my optical ignition came in. super cool. thanks for the heads up on this Jon

DoctoRot wrote: ...I'm thinking about buying some 304 or 316 stainless rod, cutting thread and welding a stainless flange nut on the end. My only concern is that this wont be strong enough....

For what it's worth, on my 650 I replaced all my engine mount bolts (actually pretty much every external bolt and nut on the bike except for the fine threaded, which I can't find) with standard A2 stainless, I also run a custom made stainless swingarm pivot bolt and rear axle - been running like that for the past ten years, no issues whatsoever.

Great work on the bike, I especially love those black hubs and rims with the shiny spokes (stainless??).

woohoo another c5 ignition in play!!!!!

i have purchased one for a buell project i have simmering.

paul is a very knowledgeable/helpful guy.

nice to see folks using his product.

can't wait to see how it works for you.

leon

OnkelB wrote:

DoctoRot wrote: ...I'm thinking about buying some 304 or 316 stainless rod, cutting thread and welding a stainless flange nut on the end. My only concern is that this wont be strong enough....

For what it's worth, on my 650 I replaced all my engine mount bolts (actually pretty much every external bolt and nut on the bike except for the fine threaded, which I can't find) with standard A2 stainless, I also run a custom made stainless swingarm pivot bolt and rear axle - been running like that for the past ten years, no issues whatsoever.

Great work on the bike, I especially love those black hubs and rims with the shiny spokes (stainless??).

Thanks. The spokes are cheap zinc plated Thai kit. If I were doing it again I would pony up the cash for a buchannans stainless set. The some of the spoke heads on this set were not the right angle so I had to bend them in a vice, and the nipples are not very uniform in size so I ended up rounding a couple when I trued the wheel. It worked out in the end but less than ideal for sure. Down the road is like to get some wider aluminum rims and when I do that I will upgrade spokes as well.

After talking to two machinists whose opinions I value, both thought 316 will be fine, as the bolts are pretty lightly loaded, and will be stronger than the factory motor mount bolts. the close tolerance is the important part. I guess I will get some of 316 as well

OnkelB wrote:
For what it's worth, on my 650 I replaced all my engine mount bolts (actually pretty much every external bolt and nut on the bike except for the fine threaded, which I can't find) with standard A2 stainless.......

Which ones are you missing in stainless? Ed