9.8 110 mercury wont throttle up anymore

[moist giraffe]

I have a 9.8 110 mercury in the year of 1970 unsure that exact year but I took it out on the river it had a hard time throttling up but it did for some time then throttled down and didn't speed up anymore anyone know what might be wrong

 

[racerone]

Has a new water pump impeller been installed every 3 years ?---Check spark.----Might be running on 1 cylinder.-----If it has a plastic piece on top of carburetor , Is it cracked / broken ?-----Post the results of a compression test.

 

[moist giraffe]

Could be the impeller

 

[racerone]

Motor may have overheated.----Many folks just do not know how critical it is to maintain these motors.-----There is nothing that warns you in case of overheat.----The motor runs until major damage is done.----Very simple to trouble shoot this motor.----Good luck with it.

 

[moist giraffe]

Motor may have overheated.----Many folks just do not know how critical it is to maintain these motors.-----There is nothing that warns you in case of overheat.----The motor runs until major damage is done.----Very simple to trouble shoot this motor.----Good luck with it.

The guy I got it from said it sat in storage for afew years but I did clean the carb and put in new gaskets in fuel pump but I haven't check the impeller

 

[racerone]

Sorry----I can not see , hear or touch your motor.----They are simple to trouble shoot and repair.

 

[Chris1956]

Check the compression to make sure she is not damaged. If compression and spark are good, try richening the carb idle mixture 1/8 turn and see if that helps.

The larger Mercs (IL4, IL6) of that era needed a rich idle mixture to allow them to rev up. If you set the idle mixture to idle smooth, it was too lean to allow the engine to rev up. They just bog or sometimes stall. I am not sure about the smaller ones, however.