Topic: Head oiling issues.

[katman]

Okay guys, thanks for the anwsers on my 750F supersport cam question. My freind just purchased this 75 supersport in very nice shape.
He rode it about 4 miles when it started making a horrible noise from the top end. We've pulled the motor and got the valve cover off and the
valve train and cam on # 1and 2 cylinder is compeltely dry. No oil. 3&4 is nice and wet. Cam tower and caps were scored real bad. He has found a replacement 750F cam and towers and valve train but what should we be looking for to cause no oiling to that side of top end.
Thanks

[70CB750]

Under the cam tower is a little nozzle - most likely it is clogged. Thats how oil gets up to the head.

[madScientist]

70CB750 is right. There are two "jets" on the F head that live under the cam tower. If I remember right it's where the little o-ring goes as well. Those are most likely clogged up.

[ekpent]

Good idea to drop the oil pan and see what else may still be floating around in there,  fresh metal now I'm sure. See any silicone sealant anywhere doing teardown from previous work ? There are some additional galleries etc. that should be cleaned also so it does not repeat.

[strynboen]

yes silocone sealing floting araund are tikking bombs in a lube cirkulation system

[MCRider]

Plugged oil jet usually a result of someone being in the engine for repair, and using a silicone based hardening type gasket sealer. The sealer squeezes into the internal side of the engine, hardens, bits flake off and migrate to that orifice under the camtower. Embulism.

Always use non-hardening non-silicone sealer, like Gasgacinch.

I've heard of a blockage from debris without an engine repair, but its very rare.

[70CB750]

The jet is in the read circled area - not sure witch one on this schema.

[katman]

Great Guys,
Were pulling the cam and towers off tonight. Will check it out.

[MCRider]

Great Guys,
Were pulling the cam and towers off tonight. Will check it out.

#6 in the diagram is the "oil orifice". IT is stuck in a hole under the cam tower, near the chain tunnel, intake side, and has a small O Ring on top of it. THE ORIFICE can be pulled out and observe if there is debris under it blocking the hole.

The matching O Ring at the other end of the tower just seals the end of the oil pathway thru the tower, and cannot be blocked.

[dlhoulton]

I'm rebuilding a 77 cb750F that had that same exact problem. The PO had worked on motor and there was oil starvation to same area. As I was taking motor apart I found out that the PO had put the gasket under the cylinder on wrong (gasket between crankcase and cylinder). If you have put one on before you know that it can be put on the wrong way and block the oil flow to the area. That's something to consider as your working on it.

[PeWe]

Do not forget the other 2 small o-rings under the cam towers where there is no holes in the head (oil orifice), only in cam tower. Important that the o-rings are here and seal the end of the oil channel. No o-ring, risk for less oil pressure to cam and rocker arm/axes.

I need to check when I'm not 100% that I put them there. I have other job to do anyway so the engine will come out regardless of o-ring check.
I'll take photos on everything so I can later check if needed. The digital camera era make  this so easy.