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Old 10-10-2023, 07:51 AM   #1
900Rebuilder
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The 2 main frame bolts - 900ie / 900

Hi All,

Been busy doing lots of trial fitting on my 900 build as bits come back from powder coating and the local engineering place.

A quick question that I'd like info and hopefully advice on. I have a 900ie engine going into a 900 carb frame which fits fine with the known exception of the different sized bolts that hold the engine to the frame. I understand that typically the frame is drilled from 10mm to 12mm and the newer type bolts are then used which is I'd imagine no big deal, however on mine the rear bolt screws into a captive nut in the frame so cant easily be drilled out unless it was and then re-tapped to 12mm. Is this unique to early 900's as I thought it was just a long bolt with a nut / washer on the end of both?

Cheers,

Ben
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Old 10-10-2023, 08:30 AM   #2
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Well when I fitted an ie lump to my 94 frame, it was like you say a straight forward matter of opening out the holes, no threads in the frame. However I did have to slim down sockets to fit the nuts inside the tubular bosses. One other mod that you may well need to do is to the small frame cross member that's positioned just over the top of the rear cylinder inlet manifold. On the early ie's (at least) Ducati put in a small indented flat because there wasn't quite enough clearance. Pity you've already had the frame painted. Hope it all goes well.
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Old 10-10-2023, 09:40 AM   #3
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The frame on mine is 1999 and has the rear bolt screwing into the frame, however it originally came from an M600 but it suggests to me that all the carby frames with 10mm bolts probably have the same setup? (oddly the bolt goes in from the left side rather the the right as shown on the parts diagram).

From memory, I don't recall there being a captive nut, rather just a threaded frame? either way, shouldn't be too big a deal to either re-thread it 12mm or just drill it out for a nut/bolt setup.

The problem is likely to be fitting the larger bolt head, nut and socket into the smaller frame tube as, I recall that I needed to buy a pair of 'slimline' long-reach sockets to fit my crashbar/front engine mount bolt (nuts on both ends) as a standard socket was neither thin enough nor long enough and, obviously the nut on a 12mm bolt will be larger still so the problem is greater but, doable as per Bitza's post above.
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Old 10-10-2023, 10:42 AM   #4
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Thanks - both

Yes, I've already found the socket issue and thought it was down to excessive powder coating! My mistake....

The other reason I commented on the threaded insert is that it is quite thick and even if I drilled through it it may not provide the clearance for the new bolt to then fit into the nut because its effectively too short.

I do have some crash bungs that I wasnt going to fit which come with some basic threaded bar - I was not sure how good this would be for the job in hand and was going to stick with Ducati bolts instead.
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Old 10-10-2023, 11:24 AM   #5
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The bolt in my crash bungs is a purpose made shaft with threads either end rather than fully threaded rod.

I can't imagine threaded rod is ideal as the threads would cut into the engine and, well it just looks cheap.

Presumably the thicker area where the thread is could be re-threaded to 12mm easily enough. Through drilling may require a significantly longer bolt and given the speciality design of the bolts, you may struggle to find such a bolt off-the-self?
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Old 10-10-2023, 12:01 PM   #6
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Speaking of engine bolts.... am trying to remove engine from 900ss frame, and according to the wonderful world of Haynes I need to "counter hold the engine front mounting nut."
What size nut is it ? The sockets I have either won't fit in recess or fit on the nut.
I think it's a 14mm and I'll need a thin walled socket to hold it. Am I right ?
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Old 10-10-2023, 12:20 PM   #7
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Mine are 14mm, I had to buy 2 slimline, long reach sockets as nothing in my toolbox would fit.
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Old 10-10-2023, 02:44 PM   #8
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This is why I mentioned the threaded bar / crash bungs as it appeared to be both cheap and potentially dangerous way of holding the engine in. I'll probably go down the new bolts and increasing the diameter of everything connected route.

I was curious to see if the engine could be shimmed to fit the 10mm bolts but from research have decided that Ducati must have increased the bolt diameter for sound reasons supported by the fact that there are expensive aftermarket bolts available.
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Old 12-10-2023, 07:51 AM   #9
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Update - bought some batteries for my Dad's old Mitoyoto calipers and measured everything (like I should have done in the first place) and found that the front mount is 10mm and its only the rear thats actually 12mm. Going to see if I can get a spacer machined to allow the ie motor to fit the frame as I still have the original lump in bits and a JE 944 kit that I was going to have it rebuilt with.
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Old 12-10-2023, 10:04 AM   #10
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I have heard that the early ST2 (1999) used to snap the rear engine bolts and that they were upgraded to 12mm from 2000. I think there was a frame colour change (to Silver) for the ST2 at the same time which identifies the larger bolt models.
As the water cooled 944 was probably the most powerful and heavy engine that frame housed up until then, it probably hadn't manifested before.

Ducati most likely made the modification across the entire range at that time to facilitate interchangeability and make way for more powerful engines which were in the pipeline.
The change would definitely have been applied to the 2001/2-on "ST" type Monster frame with the rod suspension link.
Intermediate hoop models (2000-2001) might be a mixture?

I'm sure I have a spare engine bolt somewhere but no idea what diameter.. Hang on...
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Old 12-10-2023, 01:01 PM   #11
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Quote:
Originally Posted by Mr Gazza View Post
I have heard that the early ST2 (1999) used to snap the rear engine bolts and that they were upgraded to 12mm from 2000. I think there was a frame colour change (to Silver) for the ST2 at the same time which identifies the larger bolt models.
As the water cooled 944 was probably the most powerful and heavy engine that frame housed up until then, it probably hadn't manifested before.

Ducati most likely made the modification across the entire range at that time to facilitate interchangeability and make way for more powerful engines which were in the pipeline.
The change would definitely have been applied to the 2001/2-on "ST" type Monster frame with the rod suspension link.
Intermediate hoop models (2000-2001) might be a mixture?

I'm sure I have a spare engine bolt somewhere but no idea what diameter.. Hang on...
Typical - my friend just sold a mint low mileage ST2 for £1500 - I could have bought that just for parts and broken the rest knowing so much was interchangeable.

Also struggling to get some riv-nuts back into the RR tail tidy after powder coating. Been using the YouTube hacks to no avail and simply stripping the threads out of M6 nuts instead so might have to purchase the actual tool for the job
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Old 13-10-2023, 09:19 AM   #12
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What is a Ford GPW?
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Old 13-10-2023, 01:16 PM   #13
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Quote:
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What is a Ford GPW?
Ford's version of the Willy's jeep, both produced to a standardised US army design, extensive use from WW2 onwards, I believe
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Old 13-10-2023, 03:51 PM   #14
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Quote:
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Ford's version of the Willy's jeep, both produced to a standardised US army design, extensive use from WW2 onwards, I believe
100% correct - its a Jeep made by Ford not Willy's. Only real difference is the F script on various parts, however everything is interchangeable and many on the road are bitsa's. Mine is I'd guess 90% original with some new repro parts where needed and Willy's fenders as original Ford ones are about £400 each side.

next gas station near my location
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