749R Leaks oil (clutch and crankcase breather valve)

[748R_bb155]

My friend has a 749R with the Lanzi wss corse engine kit(heads, cams, innlet manifold, ecu, exhaust).

On one of our trips to Germany the stock crakcase breather valve(plastic), split in the middle, it also had signs of oil leaking through to
clutch seal (the large simmerring).

One the next trip, the stock breather valve was exchanged for the
DP performance one(alu). After about 1-2 hours of use, the cluch seal were leaking again(seal was change prior to our trip).

Any suggestions for fault finding, new parts to solve the problem ?

I'm just thinking, can there be a large over pressuire in the crank case, due to a possible block after the breathervale and berfore the breather box.

to much blow-by worn piston rings ?? (the bike has total running of 7000 km, ca 2500 with kit installed).

EO

[acruhl]

Maybe do a leakdown test to find out?

I suppose it could be possible that the large gear on the input shaft has some imperfection on it hosing the seal, but crankcase pressure seems equally likely based on your description.

It's entirely possible that there is blowby from the rings I think, but a leakdown test would help confirm.

[DukeDesmo]

The clutch pushrod seal could be failing because the pressure plate bearing is tight and the pushrod is rotating, wearing out the seal?

[tye1138]

The oil seal is probably the center shaft seal. I just had to deal with that on my 749R and its a quick fix. I don't have the pn with me, but if you look it up on the parts list, its the shaft that comes off the transmission. The xx9 bikes push rod shaft, isn't manufactured properly and the section of metal that touches the seal isn't smooth enough. You need to lightly sand that area and put a new seal in... it should be good after that!

[demontech]

when you put the new breather valve on did you purchase an alluminum gasket from the older models? it needs that to seal. i personally would remove the reads from the valve and get the setup in the airbox. make sure the clamp is sealing properly, mine leaks from between the hose and the spigot if the clamp is to big.
preload the spring on the seal a little-should help if it is coming from their. seal the hub bolts thouroghly, and make sure the oring under the hub spacer is their and is actually sealing...

[748R_bb155]

The kit is the 7735 EURO Motorkit racing plus for 749R(ref Startseite Ducati Saarland). (and I som $$$$ to get the kit fittet and cams dailed, and 1000 $ for some "smal" parts)

Redline is about 13500 rpm.
The bike is serviced every 2500 km (that means every summer, the owner lives in North Norway/and afganistan), and uses the bike for a month each summer.
All servicing is carried out from the former Norwegian Ducati importer(ducati benelux is now handling imports for scaninavia).
The bike has never been dry !
The first year he had it, it was leaking from the from the seal,
it was changed. Chaged it again the following year.
The last thing whe did before going to our anual trip to germany/italy was to have bike serviced, and change the seal, the bike is now underway for servicing so the bike is ready for next summer).

It not the pushrod seal.
Could be a bad seal/or the large gear has some imperfections.

The bike pull hard from 8000-9000 and takes off at 11500 to the redline 13500. We did some tests against the gsxr750 k6(slipon-PC), and the 749r has better accelleration, and higher topspeed, dont know how fast cause the speedo on the 749R stops at 280kmh(ducati built inn). They left me for dead(on a 996 at 265kmh gps measured speed). (my AIM display shows 250 kmh at 265 on the gps (gps and aim accurate withn 2 km up to 230). And as far as I go only gps speed is accurate !

We changed the gearing from the first year(month) with the kit, he wanted 2(4) theet up on rear, but the shop just orderd the standar ducati kit 14 front and 2(4) up on the rear and the bike was going throuht the register FF.(they did not compy with his order). I suspected them of installing a 14 front sprocket, so he changed it to a 15 front helps keeping the rpm down somewhat(at least on the autobahn).

He currently thinking of a 848 kit for it.

EO

[tye1138]

Yea, just to let you know... that motor is a ticking time bomb at 2500km service intervals. With a 13k rev limit, the motor needs to be serviced every 700km. Also, the crank case pressures at 13k are much higher and the stresses can also create the issues your seeing. Oil weeping through seals and the breather system, could be a consequence of that RPM.

The RS cam's and 13k RPM red line are really for racers who need that extra 5hp for competition and are willing to re-build every time they race. IF timed properly, they give the "kick" you're describing.

Though I'm shocked he rides it on the streets...

[Ben710]

Originally Posted by tye1138

Yea, just to let you know... that motor is a ticking time bomb at 2500km service intervals. With a 13k rev limit, the motor needs to be serviced every 700km. Also, the crank case pressures at 13k are much higher and the stresses can also create the issues your seeing. Oil weeping through seals and the breather system, could be a consequence of that RPM.

The RS cam's and 13k RPM red line are really for racers who need that extra 5hp for competition and are willing to re-build every time they race. IF timed properly, they give the "kick" you're describing.

Though I'm shocked he rides it on the streets...

How do you know?

Ever had one of these Corse engines?

Please Tye...

[trussdude]

Originally Posted by tye1138

With a 13k rev limit, the motor needs to be serviced every 700km.

Please tell us what needs to be serviced every 700km.

[demontech]

Originally Posted by Ben710

How do you know?

Ever had one of these Corse engines?

Please Tye...

can attest to that, 12000 is a ceiling for dependability in my mind. 12000 and up will take cases out
i run my 999 to 11500-11700 max and i took mine out(granted it took a long time)

[Ducati23]

There isn't many of those engines as equipped laying around. DemonTech did mine and @12k is where you hold the line or it will fail. I don't know where Tye gets his information but I know mine is firsthand and DemonTech's is from Chandler and Pegram. Standard 749R engines are not in the same league.

There are a few people who bought these kit parts from CorseSuperbikes, BMS and Pegram. Anyone who has them and raced them should be well aware that they have limitations. Oil leaks from case pressure with adequate venting is usually due to worn rings - blow by - and gets worse with wear. Seals can play a part too but race motors should be very well maintained. Revving them to the moon creates a lot of crank pressure, so some venting is to be expected. If it gets bad look at the pistons & rings.