I bought robin 40cc How do I add servo

What are you going to use it for ,a boat or an airboat ? I was going to buy one of these to put into a big deep vee hull,but after seeing that the cylinder if offset to the side at an angle,it would be hard to mount between engine rails and the exhaust would be down in the hull which wouldn't be good.It also doesn't put out a lot of rpm. It might be suited better for an airboat though.

some problem to load image

for boat .. Here are some pictures .. I took a long time to buy it is difficult to buy another.
Please help me to build a boat

I will try tomorrow