Mercury help needed by tech.

[DWD]

I recently bought a 1989 150 hp Mercury. It was suppose to have been rebuilt, comp. runs around 120 psi. Upon putting it in the water every time you put it gear it cuts off. I have replaced all electric components on it with used ones that came off a blown engine, carb has been cleaned and rebuilt, clean as new ones, timing is set by book. It cranks and runs good in the yard on a hose. But when put in lake it is hard to get started, doesn't idle good and when put in forward or reverse the engine justs cuts off. I hope there is someone out there that knows how to fix this problem. Thanks very much in advance. This is a 2.0 powerhead mounted on a 2.5 mid and lower unit.

[Jay Smith]

Are you sure the gear case isn't locked up?

Jay

[perfmarine1]

It is possible in yard boat sits level and water in tank is away from fuel pick up, in the water water moves to back and fuel pick up sits in the water puddle. Just a thought. I have had this happen to a customer.

[jeff dunn]

Turn up idle timing a little, and adjust trottle linkage on side of motor to give a little more air to the carbs,should idle about 1100 to 1200 on hose, when in water should fall back to around 800 rpm in gear. [Dont bother top end timing ]. Jeff

[DWD]

Thank you, I will try all your ideas. David