Head Repair springer 250 bevel drive pass through hole

[Duccout]

Hi,

Your coupling sleeve is the correct length. The shims on the lower bevel gear under the circlip should be thick enough to remove all of the end-float from the gear when the circlip is snapped into place.

I am sorry to be the bearer of bad tidings after all the work that you have done, but I can't see any other explanation for the shaft being too long other than that you have an upper bevel shaft from a 350 (which is longer than the 250) or if your engine is a narrow case, then you have a shaft from a wide-case. Can you measure the length of the shaft and let us know? The wide-case 250 shaft measures 170mm from the bottom of the shaft to the underside of the bevel gear.

Cheers,

Colin

[insanity]

Thanks Colin,

Oh Dear,
I will measure, I forgot to mention the lower circlip was absent during set ups,
and I think when i disassembled as I had only one as a sample when I went to the shops.

Cheers
Lozza

[insanity]

Hi Colin,
Well, that's me shafted....
Good to Know though.
the hunt begins I guess.
Oh, It's a Wide Case 1972 - 250, silly me should have started with that back in the first post.

[Duccout]

Hi Lozza,

That's a bummer. The good news is that you can sell the 350 set and get your money back, but not the hours of work that you have put in. New gear sets are available from Old Racing Spare Parts or Ducati Vintage in Italy (if you are flushed with money) otherwise it is eBay, where these come up fairly often, although the majority are for the narrow-case engine, so beware of this. The narrow-case shafts are waisted, so that gives you a visual clue.

Good luck,

Colin

[LaceyDucati]

Hi

That top bevel shaft looks more like a 450 as it looks nearer 190mm long. From the earlier picture are you trying to use both circlip grooves on the lower bevel shaft? Only the lower groove is used and the clip should fit snugly on top of the top stack bevel shims above the bearings. You can use either 250 W/C or 350 N/C top bevels in a 250 W/C as they are the same length. the thinner "wasted" shaft of the N/C set will make no difference in function. If you are stuck for a set of top bevels I may well have a set to sell or even exchange a like for like condition set. However it may be easier/cheaper to source some locally. Be wary of new replica sets, as some I have seen are of poor quality and don't mesh together well, a real nightmare/impossible to mesh using blue etc. I had to reject a set supplied by a customer recently and fit a good used set.

Regards Nigel

[insanity]

Hi Colin, Nigel.
I was just about to head off to bed and thought I would check in.
I looked at back to classics and balked at their price, add shipping and then with my run of luck the probability the ship carrying a
replacement set would be sunk or hi jacked by the Yeminis, it was a bit OTT for the retired not flush in the cash dept Lozza.

I was contemplating turning up my own shorter connector tube and a sleeve for below the circlip until Nigel mentioned a second
lower groove !
I haven't spotted that and will check that in the morrow, if that is the case the 6 shims sitting on the shaft are hiding it. If I find and use it and it comes together then I expect I should be safe to run with it.

I really appreciate your time and thoughts fellows.

Cheers
Lozza the loose nut

[insanity]

Hello You Awesome Fellows,

Indeed there is TWO grooves - and using the lower one works. So a Step forward,
BUT now a tooth out on the lower bevel pair when piston is tdc and the crank mark is five o clock. And if I fit the head and I rotate the engine the exhaust valve strikes the piston.
Next job = nut off and see if there is any adjustment.
Oh but there cant be any adjustment, it is on a woodruff key ! So having the mark at 5 o clock only refers to setting the idler and ignition drive ?

[insanity]

Oh, and
The shim collection pre: second groove and measurement.
Measurement post second groove
and better length image.

[Eldert]

that is a 350 widecase bevelshaft .

Eldert

[insanity]

Hi,

Thanks Eldert, so the extra lower groove allows me to use it in a 250.

I have been looking at viewtopic.php?f=3&t=3371 "lining up the dots..."
I am getting the same thing as the first image, when the piston is at real seen/felt TDC, (even dragged out a dial gauge).
At TDC the dot on the crankshaft behind the bevel gear is @ 5 0 clock, BUT the dot on the bevel gear is @ 11 0 clock, not 12 0 clock,
so the cutout on the shaft of the pinion then lies in a 4 to 10 0 clock angle rather than aligned with the case seam.

If I align the bevel dots with so the upper end of the pinion shaft is "in line with and facing the crankcase seam" the shaft dot is at 6 0 clock and the piston is
decending which seems to me to indicate the bevel gear on the crankshaft is a tooth out ?

I cant for the life of me undo the crankshaft nut. (Yep LH Thread) tried heat, impact gun etc, is it permissible to just rotate the vertical pinion shaft to
achieve "in line with and facing the crankcase seam"?
my hair hurts.