HI. well it could be caused by a faulty head gasket,plugged carb or hairline crack in coil and once it starts to warm up the crack expands and craps out .check all the above but when checking coil, check it before and after it dies with an ohm meter and readings should be the same before and after
no it is all in how you take care of it
You will probably have to drop the lower end of the outboard. Its sound hard but really it is usually quite simple. The pump is nothing more than rubber impeller on a brass collet.
The weight of a 1979 70 HP Mercury outboard with 20 inch shaft, power tilt and trim is 239 pounds. I would expect the somewhat newer motor to weigh about 5-10 pounds more. Hope this helps.
I am assuming you must be having more problems than just putting the lever back into neutral right. Dont worry my Mercury 9.8 is all screwed up to.
== Is this engine the plastic cowling with idle knob and choke knob on the front pull it to choke and turn to raise idle? = Read more: http://www.justanswer.com/questions/1dpbt-25-hp-mercury-outboard-water#ixzz0HH1RenQM&B
A 9.8 hp Mercury outboard, serial number 4387693, is a 1976 year model. The carburetor used on the 15 hp model, is of a completely different design, and will not interchange with the 9.8 (110) model.
My 115 EFI mercury outboard would only generate 4200 RPM. The power gradually reduced and finally levelled off at 2400 RPM. I have had other problems in the past relating to power settings. Fuel injectors and impellor have been eliminated as potential causes.
i have a 70hp mercury outboard older late 70's model and the cylinder compression is 135 across the board. it shouldnt be below 100 psi and not more that 15 between any 2 cylinders
45 minutes.
your motor is a 1975 200 20hp you can get more info here: http://www.autorepairmanuals.biz/site/573683/page/599300
no year, 2stroke? 4 stroke? VRO?... my guess would be either incorrect gap or bad fuel mix if its a 2 stroke. could also be water in the cyl. without more info, thats all i got.
My 75 Johnson is 50:1. If you use a synthetic oil you won't need to worry about it and no more smoke from too much oil