When its cold

When it's cold it takes the 100% mineral oil a long time to lift the blade when the position control lever is disengaged. But when I engage it- it will lift the blade at once. Is something out of wack. I just put a new hyd cyl on and didn't notice any bent linkage. After 4 driveways it will start to work without disengaging lever.

My guess is your issue is related to the high oil viscosity when cold and the design of the 9N/2N/8N hydraulic pump. Harry Ferguson designed the N series with a Scotch yoke type pump with a displacement of 1 cubic inch per PTO revolution. Only when hydraulic flow is required does a little valve (like the intake/exhaust valve on your Briggs lawn mower) get opened to allow the pump to suck in oil. When things are status quo (no implement required to be raised) the pump doesn't pump anything, parts move but nothing gets pumped because the intake valve is closed. The position control lever changes the mechanical feedback to that intake valve. I suspect your problem is the mechanical feedback is barely allowing the intake valve to open and the thick oil when cold is just really hard to suck into the pump. When warmed up, the thinner oil is easier to suck in. I had the opposite problem when I put an engine-driven hydraulic pump on my 8N. Lowering the implement requires a similar small exhaust valve to open to allow fluid to leave the lift cylinder. The high output pump that I drove off the engine would immediately raise my implement to the max and hold it there. My solution was to add a variable flow control valve so I could control how much external hydraulic flow that I was adding to the 8N hydraulic system. The excess flow was routed back to sump through some quick disconnects at the back (and a return filter) so I could run a hydraulic log splitter off the tractor when needed. Also, are you using the lower viscosity hydraulic transmission fluid instead of the high viscosity 1950's spec oil? I've had no issues using the HTF.

I'm using that thick 90 wt molasses. Just wondered why it would raise with position control -Thanks for the explanation.

(quoted from post at 19:22:37 02/13/18) I'm using that thick 90 wt molasses. Just wondered why it would raise with position control -Thanks for the explanation.

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If you are going to use the heavy oil in the winter you should park the tractor in your bedroom during the night. If you poke a heater under your tractors rear end for awhile before you use it in cold weather it should help the 90w flow better.