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New 450 engine build top end oil flow,

Posted: Fri Apr 11, 2025 7:09 am
by graeme
How many kicks (by hand) with the plug out should it take to get 25w 50 oil to show in the head ?
My arm is about to fall off and still no signs of oil in the head. Looking from the exhaust rocker cover.
I expect to see oil coming out the cam end bearing, opposite the bevel.
I built a Darmah engine and that took a while to show oil in both heads.
Graeme

Re: New 450 engine build top end oil flow,

Posted: Fri Apr 11, 2025 7:59 am
by graeme
I’m thinking that I’m not spinning the engine fast enough?

Re: New 450 engine build top end oil flow,

Posted: Fri Apr 11, 2025 8:04 am
by blethermaskite
Graeme, if you have a decent power cordless drill put a 1/2" drive socket on it and spin the engine from the gearbox sprocket nut, When you just start a running engine it will take maybe 3/4 seconds for the oil to start flowing at the head .....that's about 60 revolutions of the crank quite a lot of 'hand' kick starting. What I normally do is back feed the head oil supply with a pressure oil cam from the bevel gear end of the camshaft (I know it will leak out at the cam lobes but it will fill back to the pump) did you 'prime' the pump by running it in the timing cover by hand until it flowed before fitting ? Cheers George

Re: New 450 engine build top end oil flow,

Posted: Fri Apr 11, 2025 9:21 am
by themoudie
Morning Graeme and George,

As George suggests, using a pump oil can/purie to fill the pump oil galleries during assembly and then oiling the end of the cam after assembly. However, having never used the drill on the drive sprocket shaft, I don't see why it shouldn't work. My alternative method is to use Oregon semi-liquid red grease on running surfaces during assembly and once the engine is in the rolling chassis, to remove the spark plug and push the bike in gear around the yard a few times, until the oil can be seen coming from the drive end of the cam.

Been a great past month up here and already due the first oil change of the year on the 450 MKIII. :D

Good health to you both, Bill

Re: New 450 engine build top end oil flow,

Posted: Fri Apr 11, 2025 12:15 pm
by Duccout
Hi Graeme,

It takes a lot of kicks to get the oil to flow! I think that Bill's method would be quicker.

Cheers,

Colin

Re: New 450 engine build top end oil flow,

Posted: Fri Apr 11, 2025 9:32 pm
by graeme
Ta for the replies.
When you say to prime from the bevel end of the cam (I think that is what is meant?) the bevel end of the cam is not drilled through. Desmo cam.
I used plenty of assembly lube in the head, rockers and cam.
Everything was oiled when assembled but it has sat for many months, so I assume it has drained down.
I’ll try some more with the kick start while the bike is still on the bench.
If that fails or my arm falls off, I’ll try the push it around in gear.
It’s just about ready to come off the bench anyway.

Regards
Graeme

Re: New 450 engine build top end oil flow,

Posted: Sat Apr 12, 2025 1:38 am
by Jordan
Just info:
Not a new build, but a running 350 cold start video: https://www.youtube.com/watch?v=5oyKRn_83P4

It's much slower when hot.

Re: New 450 engine build top end oil flow,

Posted: Sat Apr 12, 2025 3:38 am
by graeme
Hope he remembers to put the screw plug back in the end of the crank.

Re: New 450 engine build top end oil flow,

Posted: Sat Apr 12, 2025 9:41 am
by Jordan
To do this test I installed a sealed ball bearing. It's still in there.

2-2RS-rubberplug.jpg

Re: New 450 engine build top end oil flow,

Posted: Sun Apr 20, 2025 9:13 pm
by graeme
Update,
I pushed it around but still no oil in the head.
Back on the bench I removed the cam bearing cover and dribbled about 80ml of oil backwards through the head and cylinder to the pump. Let it settle for a while.
2 pushes on the kick start and shitloads of oil in the head.
Never had to do that before.

Jordan, what fitting did you use to connect the hose to the end of the crank ?

Regards
Graeme