Recommendations for 450 Desmo service intervals

[Paul1098]

Had a good trawl thru' the forum but can’t find anything on recommended service intervals and as I have no experience of the bevel engines wondered what people did?

I have a copy of instructions for use which states every 310 miles
Check valve clearances
Tighten cylinder head bolts

Every 1240 miles
Change oil
Clean float bowl, main jet etc.

Every 6200 miles
Unscrew crankshaft plug and clean out debris.

The Haynes manual suggest that valve clearances are done when oil change is done at 1200miles or monthly.

I can understand replacing the oil every 1000 to 1500 miles or yearly but do the valves need doing every 310 miles or even 1240 miles and do the cylinder head bolts need tightening every 310 miles?
I’m only used to 90’s onwards belties so find these service intervals very short but maybe materials and manufacturing were poor in the 70’s.

[Duccout]

Hi Paul,

It is pretty standard practice to change the oil every 1000 miles because there is no proper oil filtration on these old engines; the valve clearance checks are just a precaution - it all depends on how enthusiastic a mechanic you are...... Don't forget that Ducati has been making mechanics out of riders for over 70 years! Personally I would check them every 1000 miles as there are only two valves and access is easy.


Cheers,

Colin

[Paul1098]

Hi Colin,

It makes sense to check the clearances at the same time as doing the oil. Not sure how many miles i'll put on the bike so it'll probably end up as a yearly service.

On the belt drives i've often found it's the wire collets crushing that causes most of the valve clearance change so collets are changed every time, is it the same with the bevels?

Cheers
Paul

[Duccout]

Funny, but I have never found any collet wear on my bevel engines; I wonder if it is due to the longer rockers on the old 80 degree heads, which are much easier to depress against the closing springs than the modern vee twins?


Cheers,

Colin

[Paul1098]

Hi Colin,

It could be down to the different rockers or the increase in RPM on the belt drives giving the collets a harder life.

Cheers
Paul

[graeme]

Hello Paul,

Change your oil every 1000 kms

Before you ride it check the valve clearance throughout 4 strokes.
You may find that the clearance closes up through the cycle.
Many of the Desmo single cams are not ground correctly and close up the gap through the cycle.
This can cause the cam and rockers to bind and damage to the rocker or cam.
The old way to fix this was to set the gap at the tightest point.
This will have the gap too big for the rest of the cycle.
Or measure and mark the cam tight spot and lap it down.
Some are worse than others.

I haven’t had to adjust shims under 10k kms or more. 310 seems like a misprint
Same with re torque the head bolts.

Regards
Graeme

[blethermaskite]

Yeah.....same as all above advice.....don't know what that head bolt torque is about? when you have had the head off (for whatever reason) torque it once then again after about 100 mikes and forget about it! Graeme is absolutely correct on valve clearances.....obviously you will probably only need to check them every now and then, (as opposed to actually having to reset) say at your 1000 mile oil change interval, but be careful to rotate the camshaft through the full 360 degrees several times to find any tight spots and that (tight spot) is where you set the closing rocker valve clearances (almost always not at the recommended TDC)
Cheers,
George

[Paul1098]

Thanks Graeme/George,

I'd seen comments about the closing cam not being that accurate and the need to check the clearance in various places. I'm hoping somebody has done the hard work of lapping the high spots already. The bike has had the valve clearance done and bevel drive shimmed by a bevel specialist prior to me purchasing the bike so that side of things should be OK, just a matter of keeping on top of servicing now.

Is there a torque setting for the heads or is it just 'tight' as per other fasteners?

Cheers
Paul

[blethermaskite]

Paul, I would check the closer clearance anyway......just to be sure......even people who think they know what they are doing can get this critical setting wrong, with potentially very expensive results.
Cheers,
George

[blethermaskite]

Paul, I would check the closer clearance anyway......just to be sure......even people who think they know what they are doing can get this critical setting wrong, with potentially very expensive results.
Cheers,
George