About ready to zip up the engine.

Tony_Ducati

Well this is easy so far. Two questions ...

1) Do you prelaod (via shimming) the main bearings on these engines, so the crank is quite firm to turn when cold and ...

2) It is usual policy to NOT use a center gasket, just that nice Loctite 515. This donk had never been apart and it appears a gasket is a standard fitment but I've been building "the other engines" for many years without a gasket and never had a leak. Just one more thing to go wrong in my view. What is the general opinion?

Ta.

hauge

0,15 preload and no gasket.
I thinnk manual says 0,10-0,40mm preload
Gasket is hard to get and are not used ob newer engines.

Tony_Ducati

Excellent!!

marvin

.006" Preload. Use DucatiBond (ThreeBond 1215)or Yamabond, not loctite 515, no gasket.

You should also set the end play on the transmission shafts and the shift drum. Set the squish at about 1mm.

Tony_Ducati

Oh one more thing ...

Barrel studs ... replace?

sp2 boy

More bead blasting?...😉

marvin

Barrel studs should be fine.

Use DucatiBond on the barrel base gaskets as well.

You will need to make a wrench to torque the cylinder head bolts. Or borrow one!

hauge

Tony_Ducati wroteBarrel studs ... replace?

Some years of the 900 ss had studs that where to hard and snapped. Those looks like stainles. The proper ones are brownish. I don´t think the wrong type went into the 851/888 engines.

Tony_Ducati

hauge wroteSome years of the 900 ss had studs that where to hard and snapped. Those looks like stainles. The proper ones are brownish. I don´t think the wrong type went into the 851/888 engines.

These ones are pretty tough steel - nothing stainless here

Tony_Ducati

marvin wrote.006" Preload. Use DucatiBond (ThreeBond 1215)or Yamabond, not loctite 515, no gasket. You should also set the end play on the transmission shafts and the shift drum. Set the squish at about 1mm.

What's not good with Loctite 515? Keen to know as I've never had an issue. Oh I know all about end play on tranny shafts and shift drums!!!!

Tony_Ducati

marvin wroteBarrel studs should be fine. Use DucatiBond on the barrel base gaskets as well. You will need to make a wrench to torque the cylinder head bolts. Or borrow one!

Oh the heads won't be going on yet, just the bottom end together. I've found a few rusty valves which shits me to tears as I now have to spend money!!

Mr.R

Here's my tuppence on it...
Don't fit a centre gasket, 4 Thou' on the crank preload, go for the tighter end of the gearbox shaft tollerence and DON'T forget to shim the swingingarm!
Also while your at it blank off the small oil feed hole in the RH case under the rear barrel, it isn't needed and most likely will save a future oil leak.
I use 4mm grub screws on Brad's recommendation.

Never tried the Loctite 515 but have used the Ducati Threebond/Yamabond/Kawabond without any problems since the mid 80's.
Subaru Threebond sump gasket sealant is exactly the same stuff as the Ducati kit, but costs about a 1/3rd of the price and comes in a much bigger tube.

Steve R

Tony_Ducati

Mr.R wroteHere's my tuppence on it... Don't fit a centre gasket, 4 Thou' on the crank preload, go for the tighter end of the gearbox shaft tollerence and DON'T forget to shim the swingingarm! Also while your at it blank off the small oil feed hole in the RH case under the rear barrel, it isn't needed and most likely will save a future oil leak. I use 4mm grub screws on Brad's recommendation. Never tried the Loctite 515 but have used the Ducati Threebond/Yamabond/Kawabond without any problems since the mid 80's. Subaru Threebond sump gasket sealant is exactly the same stuff as the Ducati kit, but costs about a 1/3rd of the price and comes in a much bigger tube. Steve R

Well in the interest of productivity and being a tight-arse, Subaru it is!!

Tony_Ducati

Tony_Ducati wroteWell in the interest of productivity and being a tight-arse, Subaru it is!!

Such a tight arse in fact, that I bought some on eBay that's coming from France, for about a tenth of the cost of the Loctite.

So in the meantime, I'll refinish the swingarm - who likes polished or should I get it re anodized?

Mr.R

Yeah I scored mine from a car speed shop on E-Bay.
Not having the magic "D" or Ducati in the discription often sees the price drop through the floor IME.

On another note I found British made Plasma hardened Stainless Steel race valves for less than a 1/3rd of the price of the Ducati valves.
It's also possible to fit +1mm 34/30 valves in the '92 851 heads without putting in larger seats.

Steve R

marvin

Tony_Ducati wroteSuch a tight arse in fact, that I bought some on eBay that's coming from France, for about a tenth of the cost of the Loctite. So in the meantime, I'll refinish the swingarm - who likes polished or should I get it re anodized?

To anodize it you have to remove all of the steel inserts.

Tony_Ducati

marvin wroteTo anodize it you have to remove all of the steel inserts.

Yes ... I know .... that was a concern. Polish it be then!

Tony_Ducati

Mr.R wroteYeah I scored mine from a car speed shop on E-Bay. Not having the magic "D" or Ducati in the discription often sees the price drop through the floor IME. On another note I found British made Plasma hardened Stainless Steel race valves for less than a 1/3rd of the price of the Ducati valves. It's also possible to fit +1mm 34/30 valves in the '92 851 heads without putting in larger seats. Steve R

Nice! Ta. Oops, message too short apparently.