907 Project

Derek

Derek

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Well not really much of a project. It started a few weeks before the Masher when I got a pair of ST2 heads off eBay for a song.

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The heads have been ported but were bare with no valves, cams, rockers etc.

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The plan was to fit them to the 907ie, swapping over the camshafts, etc. (pity they didn't come with the much sought after ST2 cams :rolleyes:) and thanks to Brian & Duncan for contributing the valves. But if you compare the 2 heads in the picture below you'll see that something is missing...

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The drilling for the camshaft drive :eek:

Like the 900SS, the 907 has a mechanical revcounter, whereas the ST has an electronic revcounter and although the boss is cast in the head it hasn't been drilled. Hopefully with some help from Pict and a local engineer this will be remedied in the next week or two.
To make this more worthwhile I also managed to acquire a pair of ST2 barrels and pistons in very good nick.

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So this winter's project is to swap over the barrels and heads effectively converting the 907's engine into an ST2. The extra 40cc should give the bike a bit more grunt and is the sort of mod I don't mind doing because it will look no different externally and can be easily converted back again.

I will post some more as work progresses.
 
Could you insert the guts of an electronic tacho into the existing instrument binnacle ?
The standard cable routing is pretty horrible to get round the radiator.
 
ShedBob said:
Could you insert the guts of an electronic tacho into the existing instrument binnacle ?
The standard cable routing is pretty horrible to get round the radiator.
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It has been done, but that was fitting an ST3 tacho into the dash of a 907 that had been converted to take an ST3 engine. I'm not sure if the P7 ECU has a tacho output although it's similar to the P8 which definitely does. If it does I could use the guts from a 748/916/ST revcounter - if it could be made to fit.
Alternatively an electronic revcounter that would pick up from the switched side of one of the coils could be used. I used to have a VDO one but sold it a few years back :rolleyes: but it is probably cheaper and less hassle to get the head machined.
The cable routing is certainly pretty hellish. :thumbsdown:
 
I now have an ST2 head with a revcounter drive :)

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For machining work I can highly recommend SAS Precision Engineering in Meigle. The owner, Simon Linford has 3 Monster S4RS Tricolores.
 
The heads are now off ;

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I was very relieved when all the nuts came loose, albeit with an alarming creak as they let go.

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I'll really have to do something about the paint on the casing and covers while it's in bits.

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Any ideas for that mustard yellow paint on the valve covers? Apart from the horizontal exhaust the paint on the others is in fact quite good.
 
I roughly wire brushed the paint off (silver on mine) to clean them up then clear coated them.
Looks good. I'll post a picture when I find one.
 
Derek said:
Any ideas for that mustard yellow paint on the valve covers?
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Strip it off and polish. Covers come up nicely and fairly quick to do.
Lindsay loves doing that type of thing and he must owe you a few favours by now! :lol2:
 
No, I want to keep them the original colour. :o Remember next to none of it is seen under the all-enclosing Paso bodywork.
...and I think it's me that owes Lindsay the favours at the moment.
 
Good score on those barrels and pistons, they look brand new!
If you're looking for a match I used a place in Barnsley years ago when I was mechanic-ing in yorkshire, (they have shops elsewhere), called autopaint, very good matching and very reasonable prices, (well, they were then and i'm assuming they still trade?), I believe since I last used them they started doing an aerosol service for those without spray equipment but they did all sizes from 2L / 1L / 0.5L tins to little liquid proof bags like touch up pots that were about 200ml.
 
Interesting. Mine are the original colour too. Yellow (gold?) rockers covers and black bearing supports. Ducati, supposedly, fitted gold coloured rocker covers when they moved to the sliding openers with the spring clip in 1988 but after a year or two they probably fitted with whatever was available.
 
Strange to see a Ducati with square frame tubes. I take it that was a cost driven exercise as you couldn't see the frame under the bodywork?
 
Just received gaskets, seals, etc for the rebuild today. I was shocked to find out that 4 gudgeon pin circlips cost £14.64. £3.66 for one circlip FFS! :eek:
 
Derek said:
Just received gaskets, seals, etc for the rebuild today. I was shocked to find out that 4 gudgeon pin circlips cost £14.64. £3.66 for one circlip FFS! :eek:
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Are they the wire ones with a tang or circlips with two holes? Measure them for future ref.
 
Derek said:
Just received gaskets, seals, etc for the rebuild today. I was shocked to find out that 4 gudgeon pin circlips cost £14.64. £3.66 for one circlip FFS! :eek:
Click to expand...


One of the thing I love about ordering bits for my Royal Enfield, theres rarely a 'HOW MUCH?' moment.
Recently ordered a set of rings for mine, was about £5 delivered from India, :)
 
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