Topic: Oil starvation to part of camshaft. Blocked oil supply passage?

[Mr. Clutch]

Good news! I got the engine back together and installed in the bike. And it runs! Oil pressure is good. 60 psi cold, 20 psi warm.

Just two little issues now. When I got the bike one of the carb float bowls had a broken drain screw that had been filled in with silicon to prevent it from draining. So I got another one off ebay and the carb with that bowl began to leak fuel right at the gasket. I swapped the bowl to another carb and the leak followed the bowl. I also verified that the float completely stops fuel flow when it rises and it operates as it should. I'm thinking that bowl must be screwed up.

Also, the engine stumbles and lurches at low RPM's. It's almost like a misfire  Above 3,000 it smooths out. The first stint down the block was fine until the fuel leak at the carb flared up again. Could a poor seal on the float bowl cause a vacuum leak or something resulting in poor running?

[BomberMann650]

More likely to start a fire first

Honda has oem gaskets, get you some!

[PeWe]

If cam bearing was loose, threads might be gone. The studs can creep up which is easy to see.
I got better oil pressure with cam holders that had tighter clearance cam/ bearing. Not measured, only no flickering oil lamp at idle about 1000rpm. But I prefer at least 1200 to ensure pressure to top end and easier driving when release throttle and avoid too much deceleration. 1400rpm even better

[Doo Bee]

I modified my cam towers back in the early 80's. I took a thin piece of copper tubing -- 1/8 inch?
Drilled both cam towers on the inside near cam chain and oil feed hole. Carefully bent tubing around
cam gear and followed the housing. I JB welded the tubing in the holes. I have it on 2 cam tower sets.
One for my 915 kit and the 970 kit engines. I have never had a problem since!!! I also modified my
frame a long time ago, cutting it and JB welding aluminum slugs sticking out both sides and bolting
it together to do top end jobs without pulling engine. Good luck!!

[Doo Bee]

One more thing, I have to carefully lift up both cam towers at the same time because now they are
permanently joined! Not a big deal. I did this after wasting a 315 RC cam back around 1980 due to
oil starvation on one side---plugged feed hole. (not from silicone or sludge) Just takes a sand grain
sized particle to plug passage. Now, if it happens the other side will feed oil. I have years and many
miles on the 915 with zero issues. JB weld held copper tubing all those years and is doing it again
in the 970 motor!!!

[PeWe]

Photos?
Cam holder mod that can be useful.
Good example of frame mod too. I have Franks weld less that was easy to install and use. I have done several cam changes and pulled engine twice after head, block and all cyl studs are removed. Reversed assembly. Pull case, one man job with a lift strap.

I have another bike where frame is already cut. Too short for Frank's kit with ign switch.