M18S oil problem

[olds45512]

I've had a few that ran for 30 seconds or so before having oil pressure, as long as you lubed it up good during assembly I'd start it and see what it does.

[Mike McKown]

I THINK if you reversed the lines on the oil filter, a check valve in the filter will cut the oil flow off. If that's not correct, I'd like to hear another opinion.

[darkminion_17]

I fill the new filter with oil,as instructions are on the filter.

[Newt8411]

I started it and let it run a little and no oil yet up to the sending unit.

[ol'George]

Did you put the pressure relief ball & spring in the block before you installed the cover plate?
is the roll pin in the pump gear? did you install the gerotor (oilpump) both inner and outer?
They make #50+ @ idle.
I would not run it any more till you pull the crankcase cover and check those things, no oil circulation does bad things.
Also check as suggested if oil lines are properly routed.
Did you follow the explicit reassembly in the service manual?

[RLause]

I have found they start pumping faster if the sensor port is open, no restriction. Stop cranking quickly when you see oil come our.

[dvogtvpe]

if you didn't prefill the filter it does take time for that. you might want to spin the filter off and see if it started to fill it

[Newt8411]

I did put all the all those things in. Could the pump gears be worn that bad or the block. I'm going to put a new oil pump in it and go from there. Thanks for the info. I do have a service manual. And I've rebuilt engines since I was 12 and I'm 43 now. Never had this problem. I didn't fill the oil filter but I bib take the sensor out. And got no oil.

[ol'George]

It's possible that you used excessive sealer on the crankcase halves and it plugged the passage between the cases that leads from the screen/tube pickup, to the pump inlet where the gerotor rides.
You could remove the end cover, remove the pump cover and inner/outer rotor and gently blow air in the inlet passage of the pump cavity and is should freely blow into the suction screen.
look @ oil passage diagram in the service manual.
Normally it don't take but 1/2 minute of cranking to get oil to the sender fitting.
Did you use RTV or crankcase sealer like yamaha bond or honda bond?
I prefer those to rtv,and use it sparingly
More is not better!

[ms fowler]

I have a similar problem. I bought a used M18 to replace a blown KT17.
Installed and filled with oil, but no pressure at cranking. I was told that if there really was no oil pressure the engine would lock up in 30 seconds. I have had it running for 10 minutes....still no oil from the oil pressure sensor hole...none--or from the oil filter lines, directly from the block. Also pulled one of the valve covers and there is no oil getting there either.
I have removed the oil pump and the oil filter lines and run wires thru the passages. Everything is clear. I can see the wires at the oil pump. The oil pump spins when the engine is turned over.
Oil pressure relief valve --ball and spring are installed.
What is the chance that the pick up is broken or somehow above the oil level?

I have used synthetic oil while trying to diagnose the problem to get whatever benefit there is in synthetic oil...maybe that is what is keeping to free and not locked up, but I don't want to rely on synthetic oil for the long-term. I just want oil pressure.