no oil pressure

[LYNN OVERCASH]

newbe but have been reading posts for over a year and half and would like to thank all. there has not been a problem i had that has not been solved by just reading posts.untill now i am sumpted. i have a 48 cub that i am doing a complete rebuild. i have no oil pressure when i start it ,i let it run about a minute and a half and shut it down. did prime annd am geting oil to filter. put gage on super a and gage is good. repalced valve and spring. i guess i need to know where to start oil pump ? what to look for bad in pump ? also is there any plugs in crankcase that shop may have left out. thanks

[beaconlight]

The pump is up high and an air leack to the pick up in the bottom of the pan will do that as well as a bad pump. I am sure that some of the experts can go fur ther ib to it that that.

Bill

[John *.?-!.* cub owner]

How did you prime it? The way I normally prime one is to remove the allen wrench head plug on the left side of the engine casting right in front of the flywhaeel. It's usually about halfway behind the touch control lines. I pump 30 weigth oil in it there until it is full, then trun the engien over a few times and repeat. I do this to or three times. I don't know of any plugs that could have been left out, but someone else may. The oil pump is simply two gears, located under the small cover behind the flywheel. Did you have oil pressure before the rebuild? Normally you should have oil pressure in nor more than 30 seconds. Pull relief valve and make sure it is going all the way in it's hole. If something keeps it from seating it will let teh oil bypass. A missing crank bearing could cause no oil pressure, but that would be unusual.

[LYNN OVERCASH]

i was carefull to make sure pipe to pan was tight. did prime from hole in block and am geting oil to filter and i have replaced pressure valve and spring (they were wore a little) i have all new bearings.

[George Willer]

also is there any plugs in crankcase that shop may have left out. thanks

Lynn,

Here's what you don't want to hear. The worst plug is most likely to get left out... mostly because of Murphy's law. It's behind the cam gear. Requires tearing down the entire engine except for the crank, rods and pistons.

I suggest rigging compressed air to the oil gallery so you can listen for where it may be escaping.

[mike mix]

Under the front cover of the engine and under the bell housing there are oil gallery plugs. These plugs allow you to clean out the oil system after you hot tank the engine. If I remember the cub engine has about 5 oil plugs in the oil system. As recommened above check the oil pressure regulator first, it's the large plug on the right hand front of the engine. It has a long spring with a metal cylinder on the end. This has to move smoothly in the bore to work correctly. Thinking about it I think there is also a oil plug under the engine side cover where the valves are adjusted. My cub takes about 35 seconds to get a oil pressure reading on the gauge. If you have a service manual look for a view of the engine apart and I think it shows the location of all the plugs. Mike

[LYNN OVERCASH]

George you are right i don't want to hear that . The shop did do the cam work. i guess i will rig up something to do as you suggest. MIke i do have service manual and will check. ( might be calling mach shop) thank you LYNN.

[Maritimer]

Lynn,
How did you make out with your oil pressure problem?

[LYNN OVERCASH]

Maritimer

i droped the pan and put air to oil gallery. I am 99% sure it is the plug behined the cam gear. called mach shop and i don't think i will have a problem there.

i am in the process of tear down and back to shop.


LUCKEY ME I GET TO DO IT TWICE.