cheap fix for "tilt assist" problems?

[Mackerel_Chaser]

I have a 1985 Johnson 40 horsepower Seahorse model J40ELCO and have the tilt aid assist cylinder on mines, very expensive to replace if you can find one. So I came up with an idea and so far its working. Mine lost its pressure so I drilled and tapped a 1/8 Paintball / PCP fill nipple to the cylinder and filled it with 800 psi from a Co2 20 ounce paintball tank. So far it has not blown out the seals and its keeping pressure. I don't know the max pressure this cylinder is capable of holding but id really like to know. Its definitely working some and can lift motor a lot easier than how it was before but still a bit heavy. When I made the hole some oil came out but did not have any pressurized air in it, all the air was gone when I tapped it. The leak must be minor and leaked with time because its holding pressure at least for 3 days now. Im wanting to use my high pressure hand air pump that I use to fill my Benjamin Maurauder PCP air rifle. I can pump up to 3000 psi using this high pressure hand pump but I don't want to over do it and blow the seal or blow my face off so if anyone knows the approximate max pressure this tilt aid cylinder should have id like to know or someone just throw a guess. I did not put any oil back in it just plain Co2. I was thinking that maybe if I put a half a pint of oil like someone mentioned in this post, it can help to lift more with less force, also liked to know what type of oil can I use. The tilt aid cylinder is Johnsons part 0172908 listed at $481.61
Instead, I bought a Parker air cylinder for $25 dollars on Ebay rated at max pressure of 250 PSI to replace the original but it seems weak and it seems like a pain in the rear to remove the original so I decide to go with plan A which was tap the original cylinder and compress it with air and it worked. Again its still a bit hard to lift but there was an improvement and id like to fill it with more air higher PSI and oil but want to make sure what this cylinder max PSI is rated at.