1991 907 I.E. Rear motor mounts

[Dap_Spackled]

New member here.

Juist bought a 1991 907 IE recently, and I an doing a complete restoration. I am a very experienced wrench, but this is my first Ducati. I am down to the point of disassemble where there is nothing left but motor and frame. The top rear motor mount bolt is giving me grief, and I fear I have screwed the pooch. It is a long 14mm bolt that goes through frame and motor. Both ends turn together AND independently. Yea, twilight zone. What gives with this bolt? Was it supposed to be reverse thread? Well, not anymore. This is the last nut and bolt to free the engine. Help, please.

Free The Engine.

[injected]

It's a conventional thread, sounds like you might have to drill the bolt head out. I wonder if it was stripped in the factory, and has been like that for ever?

[Dap_Spackled]

Well, it turns out that the nut had rusted on the bolt and my efforts completely stripped the bolt threads. I had to punch the bolt thru the nut. It's done. The engine is now out of the frame. Hopefully, I will be able to find a Stainless Steei 14mm bolt that is 9-1/2 inches long (or whatever that is in cm or mm).

The entire bike is now completely disassembled. It should take awile to inspect, clean, repair and/or replace the necessary parts before reassembly. I think it will be worth it. This is a great design and a classic looking Ducati.

For those interested, I will be posting pictures of the reincarnation.

[persempre907]

Welcome .
Put the pics first and after your work.
Ciao

[Tamburinifan]

For those interested, I will be posting pictures of the reincarnation.

Very interested, keep us posted!

Where are you located?

[Kurt]

pics of the problems are very welcome, give us the bad and the ugly as well as the good!

[ducapaso]

Hopefully, I will be able to find a Stainless Steei 14mm bolt that is 9-1/2 inches long (or whatever that is in cm or mm).

There's a special tool kit to rebulid treads with "harmonic steel elicoide "
I mean a special tool "male treadmaker" and a sort of spring with a tread shape.

[samandkimberly]

Hopefully, I will be able to find a stainless steel 14mm bolt that is 9-1/2 inches long (or whatever that is in cm or mm).

These are available, but quite expensive:

http://www.nicholsmfg.com/enginebolts.html

I know a few otherwise sensible people who claim these made a serious improvement to the handling of their Ducatis. I don' t know about that, but they sure are pretty....

Sam

[persempre907]

$ 200
Are they made of gold????
I can't believe it.
Ciao

[Tamburinifan]

Something f you?
http://cgi.ebay.co.uk/DUCATI-907ie-907- ... m153.l1262

[jcslocum]

$ 200
Are they made of gold????
I can't believe it.
Ciao

Worth every penny. I have them in my 900ss and they make a huge difference.

[jcslocum]

Hopefully, I will be able to find a Stainless Steei 14mm bolt that is 9-1/2 inches long (or whatever that is in cm or mm).

Stainless doesn't have the tensile strength of an alloy steel bolt. But the proper bolt and use a proper anti-sieze on the threads.

[persempre907]

$ 200
Are they made of gold????
I can't believe it.
Ciao

Worth every penny. I have them in my 900ss and they make a huge difference.

Really?
What's the difference?
Ciao

[samandkimberly]

Really?
What's the difference?
Ciao

Here's a link explaining the "difference":

http://www.duc.bz/DUCTests_nichols_engine_mou.htm

Purely subjective. As I mentioned - I know a couple of otherwise sensible people whom I have a lot of respect for that rave over these bolts and what they did to improve the performance of their Ducatis. But is this a case of the $200 bolt being better, or the standard bolt not being set up to spec? I lube/loctite all chassis bolts, and make sure that they are seated against smooth machined surfaces or washers. I always tighten the nut side of the bolt when torquing, rather than the bolt side. I find it very hard to believe that substituting these bolts would net any improvement whatsoever over good practice.

That being said, few people pay attention to their engine bolts - they should, as this is a key part of the suspension in this case. While I think these are unnecessary, they are bigger and therefore stiffer, and well made. If I had to replace my bolts anyway, I'd consider them at least.


Sam

[jcslocum]

Really?
What's the difference?
Ciao

Here's a link explaining the "difference":

http://www.duc.bz/DUCTests_nichols_engine_mou.htm

The real benefit is the connection to the frame. On the 900 the swing arm places high forces on the engine. These bolts fit tighter into the frame (some frames have to be drilled) and the engine thru holes. This creates a stiffer frame connection that is very obvious to the rider. They also are of a better alloy. Here are some important differences:

*The bolts, nuts, and washers/spacers are designed such that the threads are well outside of the area exposed to shear forces. The stock bolts place the threads (the weakest part of the bolts) right in the shear zone.

*The bolt diameter is ~10.3mm vs. ~9.9mm. This makes the difference between a slightly sloppy fit in the frame lugs and the cases vs. a nice snug fit that should help elimate movement between the engine and the frame.

*There is much more thread mating area between the nuts and bolts.