Camshaft Burnout

Hi,

I'm still with my KZ550 restoring proyect, but in the final steps i'm having some problems with the engine.
The first time, i've burn out the bedplate and the camshaft number 4 (exhaust cam); my mechanic told me that the problem was caused by the oil pump.
I've repaired the camshaft, the bedplate and the cylinder head, and following the mechanic recommendation i've put a NOS Oil Pump.
After that, the bike started again, with no problems, and with a pressure gauge... the engine starts with about 40-50kg of oil pressure, but when the engine warms up, the pressure drops suddenly to zero .
Because of that i've burn the same number 4 exhaust bedplate :S .
Anyone have experienced something like that?
That is frustating me...

Regards,
Flavio.

Hi Flaviote,
did you clean the oilways using compressed air?

Yes, two times, before the first burn-out and before the second.
The strange thing is the oil pressure drop that happens from a second to another...

need more details !have you checked all your clearances,is there a bypass of some sort on the pump,did you replace the pickup tube/cleanout pan?ive never worked on a kz550 thats why im asking the stupid questions first;)

As the oil heats up it thins and the preasure will drop.
On a kz900 the preasure is measured at 140*f i think.

Yes, that's normal, but the problem is that the pressure doesn't fall to 10,15, it falls to 0, like there's no oil pump.
And this happened with the old and the NOS oil pump.

what is driving the pump?

The secondary shaft, this is moved by the crankshaft with the primary chain, do you think that can be there the problem?

flaviote wrote:

The secondary shaft, this is moved by the crankshaft with the primary chain, do you think that can be there the problem?

Can you visually inspect the drive gear that runs the pump? Turn the engine slowly by hand and make sure all the gears are good.

The only thing that could make the pressure drop to zero:

1) The oil feed gets starved off so it sucks in air

2) pump or drive gears are bad

3) something on the outlet path is broken or malfunctioning to take the load off the pump.

In my engine, there is a bypass valve to reduce oil pressure (when cold). If that thing was malfunctioning, it would allow the pressure to drop. I think it's a steel spring/steel ball type of thing so the spring could be weak or the ball could be dinged.

Hi Flaviote, just reading page 188 kawa service manual.
"both the oil pressure switch and the oil pressure relief valve are important for maintaining constant oil pressure......if the oil pressure is insufficient the oil pump is worn or malfunctioning or there is an insufficient oil supply to the pump".

Thanks for the tips!
I'll check the drive gear and the valves that you told me.
I want to know what is happening in that engine.
I've put everything new, rollers, pistons, rings, seals, primary and timing chains, and this is making me crazy .
Here is a picture of the burn out cam, always the 4th bedplate is damaged.

Wow. That realy sucks. How did u repair the cam and bed plate the 1st time. that head looks a lot like the kz1000 heads but the 1000 has cam bearings.
Sounds like u are on the right track. must be a pump drive , or a bypass isue. Good luck, keep us posted.