Outboard bracket modification

We have ordered our boat with an outboard motor bracket capable of holding 10HP four-cycle motor. One of its design specialty is that instead of pulling spring, there is a pushing gas spring/struts. It's made by Topiko.

Outboard bracket with gas springs

However the shipyard installed the default version for 15HP outboard motor which weights 52kg dry thus with 4 gas springs with 600N of lifting force each. We have Mercury 8HP long with electric start which weights "only" 42kg dry. It's not that big issue, you just have to push a little more to lower it down to a running position.

The main problem is that these ordinary automotive gas springs cannot withstand the saltwater, even we are on the sea for only a few weeks. After two seasons or 6 weeks at sea, the terminal eye pads were severely corroded and it started to move a little harder.
The other issue was that the springs were mounted upside down with the gas cylinder heading downward.

Gas springs mounted upside down!

Inside the gas cylinder there is an oil for the rod seal lubrication. If mounted wrong, it can result in a shorter life!

That was a time to buy a new stainless steel gas springs. The Topiko suggests 400N of the lifting force for a 8-10HP motor. There is however a problem that stainless steel gas springs are very expensive, because they are usually custom made. After searching in the European market I had to switch back to China again and bought it there. They are made from A2 stainless (AISI 304), but still better than plain steel.
They made it for me with the 450N of the lifting force.

When I was changing the gas springs on the bracket I also took an opportunity to grease all joints with marine grease.

Finished gas spring replacement

Some technical information:

• original springs: Krosno FA 21490, length 405mm, stroke 160mm, force 600N, galvanized/painted steel
• replacement springs: SmartSolu, length 380mm, stroke 150mm, force 450N, stainless steel A2