motor bogging down when first put into gear.

[duckinit]

I have a 1977 Mercury Model 200 20Hp motor that has over the years started to bogg down when put into gear. I replace the plugs once a year and run 25:1 Mercury fuel mixture. I have changed out the fuel filter and gaskets for it and that did not make a difference. Changed out the fuel hose and bulb and that did not help it. The motor runs great in idle and at any speed except when I put it in gear and start to increase the throttle. Once I start to throttle it up it seems to choke out. Once I make it past the low end throttle it runs awsome. Any ideas would be apprectiated.

 

[andy6374]

Re: motor bogging down when first put into gear.

You probably need to clean the carb.

 

[Perfidiajoe]

Re: motor bogging down when first put into gear.

I agree w/ Andy you probably need to clean/Rebuild the carb, & are you sure it is a 25 to 1 motor? I believe by '77 they went to 50 to 1, check your book to be sure. Good Luck, Joe

 

[duckinit]

Re: motor bogging down when first put into gear.

I was incorrect in the 25:1, I actually use 50:1. How difficult is it to clean the carb? I am faily mechanical but I don't want to make things worse by any means. I have no problems taking in the motor to get things done if I am not able to do them myself. Thanks for the advice Andy6374 and perfidiajoe.

 

[crem1]

Re: motor bogging down when first put into gear.

Hi Ducknit!<br /><br />Speaking from my experience, I'm an amateur, getting to the nuts and bolts of the carburator(place of attachment to the powerhead) is the most difficult part. Got to have patience, a good manual, and help from this website.<br />Whatever Tim Mathis or MercMaster says is absolute gospel.<br />Good Luck

 

[arjin]

Re: motor bogging down when first put into gear.

Same engine, same problem. Cleaned the carb, thoroughly, 2 times. I have a feeling that the trouble is in the gasket between the carb and the cilinder. On the lower side of the gasket I can see a slot in the carb with a hole to the cilinder that is leaking. The lower part of the connection on the gasket is oily showing that it doesn't connect properly. I'm not sure what the function is but it may be that it provides some extra under-pressure in the low RPM to suck up some some extra fuel. I'll try a new gasket to see if it will fix the problem. Keep you posted.

 

[arjin]

Re: motor bogging down when first put into gear.

Btw, taking out the carb isn't so hard, even with metric tools. Just take out the frame in front of the carb with the rubbers that are holding the upper cowl and unscrew the carb.

Take of the fuel hose and the plastic thingy on top that holds the choke cable and the carb is free.

If you totally unscrew the copper parts in the float chamber, be sure to unscrew the nozzle first (it's sticking out and you may damage it) and to put the plastic venturi back in place when you screw it back.