Author Topic: What would you pay for a stainless steel engine mounting rod kit for a CB750?  (Read 1826 times)

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Offline budman

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I had a set of threaded stainless steel mounting rods made to replace the rusty long bolts on my CB750 project.  I used two 10mm rods and one 12mm rod.  All three rods are threaded on both ends.  I also used stainless steel washers and nylon locknuts.  Makes for a nice clean look, but it was expensive.

I have just gotten a quote to have some of these engine mounting rods made that I'm thinking about selling as kits.  The kits would come with two 0.375" diameter 304 stainless steel rods (upper rear and lower front engine mounting points) one 0.500" diameter 304 stainless steel rod (lower rear engine mounting point), six stainless flat washers, six stainless lock washers and six stainless nylon locknuts.  The kits would come with a choice of the length for the 0.500" diameter rod, either a longer rod that will accommodate the factory foot pegs or a shorter length for custom applications where the foot pegs are mounted somewhere else, i.e. rear sets or forward controls.

Before anyone asks, yes, a 0.500" rod will replace the 12mm long bolt without issue.  It actually fits the frame and engine mounts better.  As for the 0.375" rod replacing the 10mm bolts, the fit is ever so slightly looser, but less than 20/1000" difference.  The factory 10mm bolts are actually a very loose fit to begin with.  The reason for not using metric rods and hardware is that the price of metric stainless steel rods is astronomical, literally...10x the price vs. comparable Standard Inch material in some cases.

Given the information and speculating that you would like to replace your old rusty fasteners on your CB750 with a new stainless steel engine mounting kit, what's a new kit worth to you?  $25, $50, $100, 150?  I'm looking for some feedback to see if this is doable.
Bud

1973 CB750K3 Chopper
2021 Indian Scout

Offline budman

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Bud

1973 CB750K3 Chopper
2021 Indian Scout

Online calj737

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I think the .500 rod will Not fit every bike where a 12mm was used. I personally have encountered this exact issue, and the .500 did not clear the engine mount tube. 12MM is 0.472 so thats a pretty big difference jumping to 0.50.

I've made these bolts too from 304 and 316 in metric rod, metric thread. It takes a pretty good amount of time as I also have welded nuts on one end, then turned them down to be a true "bolt". But they look great afterwards.

Just some feedback-
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Offline John Eberly

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The reason that the old bolts are rusty is that dissimilar metals in a wet environment lead to galvanic corrosion.

Stainless is worse than carbon steel when it is in contact with aluminum.

Make sure that you use anti-seize when you install these. Stainless and aluminum can be a problem in the long run.

Offline seanbarney41

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Finish the job and combine these together with precision fit, thicker, stronger aluminum engine mounts.
If it works good, it looks good...

Offline slikwilli420

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I looked into this a while back but wanted to do actual bolts in the right sizes and lengths and it was going to be like $500 per set, but we are talking about real bolts too, in either 6 or 12 point.

As for your set, they pop up on ebay and I think they are under $100. I realize that cost on this is a couple hundred if you have a shop thread them, but if you thread them and don't value your time (said no one ever) you still have at least $100 in to a set of three.

Additionally, I am with Cal, you need to source the proper material, as many will be turned off by more ill-fitting hardware, when the opposite is actually what is desired.

In the end, unless you can get to production status (say at least 50 sets??) then you probably will have a hard time getting to a competitive price.

Here is the kit, and at 64 pounds, it is going to be hard to beat.

http://www.zed-parts.com/_p/prd1/4441714691/product/honda-cb750-sohc-engine-mount-kit
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Offline kmb69

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I just put a 1/2" bolt in the lower rear mount on the drag bike I'm working on. Really tightened the engine in the frame but required running a 1/2" endmill through the frame. Went right through the engine cases no problem.

The reason that the old bolts are rusty is that dissimilar metals in a wet environment lead to galvanic corrosion.

Stainless is worse than carbon steel when it is in contact with aluminum.

Make sure that you use anti-seize when you install these. Stainless and aluminum can be a problem in the long run.

I recently had 2 CB750A case sets that the stock bolts caused the aluminum cases to corrode to the point they were bonded with the bolts. Had to machine the bolts out.

Attached corrosion article.

.....
Additionally, I am with Cal, you need to source the proper material, as many will be turned off by more ill-fitting hardware, when the opposite is actually what is desired.

In the end, unless you can get to production status (say at least 50 sets??) then you probably will have a hard time getting to a competitive price.

Here is the kit, and at 64 pounds, it is going to be hard to beat.

http://www.zed-parts.com/_p/prd1/4441714691/product/honda-cb750-sohc-engine-mount-kit

+1. Wow! That will be HARD to beat!

Offline PeWe

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I installed new engine hanger bolts last year. The old were corroded and bent.
http://www.ebay.de/itm/Honda-CB-750-Four-K2-K6-Bolt-Nut-Washer-Set-A-B-C-Engine-Hanger-New-/291318970546?hash=item43d3f6b8b2:g:mn8AAMXQSnVRZ-ai
Like the Honda original with fine threads as well.
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Offline budman

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Thanks for the input.  I'm going to scrap the idea.  Too much competition and the metric stainless rods are too expensive to make a decent return on the investment.
Bud

1973 CB750K3 Chopper
2021 Indian Scout

Offline kmb69

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.....  Too much competition and the metric stainless rods are too expensive to make a decent return on the investment.

Yep, they are pretty much standard sizes everywhere but the USA.

Offline budman

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.....  Too much competition and the metric stainless rods are too expensive to make a decent return on the investment.

Yep, they are pretty much standard sizes everywhere but the USA.

I'm going to make a set for the chopper and use a 1/2" rod.  It fits the chopper frame and engine perfectly.
Bud

1973 CB750K3 Chopper
2021 Indian Scout

Offline przjohn

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Bead blast and replate OEM parts. I have bought SS specialty fasteners  for projects that are priced right, ( Norton & Kawasaki) but  it seems without the OEM spec units here, replate is the way to go.
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Online calj737

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Bud - some handmade things just don't have a market value except to the maker. Me, I'll make mine because like you, I want the custom touches.  :)
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline budman

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Bud - some handmade things just don't have a market value except to the maker. Me, I'll make mine because like you, I want the custom touches.  :)

Yeah, I wish I could make a rear axle.  All the ones I see are beat up on the big end.
Bud

1973 CB750K3 Chopper
2021 Indian Scout

Online calj737

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I have at least one spare from a 550 in very good shape if you need it. PM me an address and it's yours-
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis