Motor bogging down

[laaroussi]

Hi All,

I have a problem with the motor and I need help. I have 1982 Mercury thunderbolt 50 HP that sometimes hesitates when full speed. Basically, when the motor is cold and I go to full throttle, the motor doesnt go to full speed but after 2 minutes the motor goes fast. is there any indication where to start troubleshooting?

Thanks

 

[CharlieB]

Re: Motor bogging down

A cold motor requires more fuel than a warm motor. Period.

The fact that it seems to run fine once fully warm leads me to think that your carb is beginning to show signs of age accumulation of mineral deposits, the idle circuit is slightly lean.

You might try opening the idle mixture screw an eigth turn out (CCW) but remember this is only a temporary fix, if the idle circuit is restricted slightly then the main circuit is also building up crud and you do NOT want to risk a high speed melt down from a lean mixture.

Plan on a carb tear down and cleaning.

 

[laaroussi]

Re: Motor bogging down

Thanks CharlieB for your response. I prefer to cleanup the carb but I wonder if I can get some help on how to cleanup the carb.

 

[laaroussi]

Re: Motor bogging down

Sorry one more question. the serial # of the motor is 7161718 can you please redirect me where I can find repair manual?

Thanks Again CharlieB

 

[Mitch293031]

Re: Motor bogging down

had the same issue recently, i took the carbs off and cleaned them and rebuilt them for $26 bucks and everything is running good

 

[CharlieB]

Re: Motor bogging down

http://1manual.com/Mercury manuals/Service_Manual_Index.htmlf

 

[laaroussi]

Re: Motor bogging down

Looks like the link you sent me isnt working or is it my computer?

I am not good in mechanic but I am willing to rebuilt/clean the carb if I can get some instruction. I checked on youtube but I have 2 carbs and they are different than the one at youtube.

 

[Mitch293031]

Re: Motor bogging down

there are several different types of carbs that came out on these engines, but they are pretty simple i took apart one at a time and looked at the other on how to put it back together until both were done and they work great.

 

[laaroussi]

Re: Motor bogging down

I will give it a try this weekend and hope for the best.

Thank you.

 

[hotrod53]

Re: Motor bogging down

I have a '77 500 Thunderbolt and here is advice that I learned in the process... unplug the connector on the motor and remove the starter, otherwise you'll go nuts trying to access the carb bolts (I have 2 carbs). Remove the top carb first and install it last, makes it easier. Be very careful with that plastic linkage the connects the 2 carbs together, it will break if you're not careful. If you have Tillotson carbs and you remove the blue plastic inlet pieces, mine never sealed again and had to be replaced. Years of stress distorts them and they will never seal again even with a new gasket. Do yourself a favor and replace the needle valves while its apart. The rebuild kits do not include all fuel pump parts, you need both kits. None of the parts are expensive, just get them all.

 

[laaroussi]

Re: Motor bogging down

I will follow your advice hotrod53. I cant thank you much all of you for your help. I started today but I am taking a lot of pictures while removing parts so that I can remember where things are. Do you have any idea where I can buy both kits. My motor is 1980.

thank you again.

 

[laaroussi]

Re: Motor bogging down

Here are some pictures of the motor. You are right of removing the starter first.