Mercruiser running poorly above 4000rpms

[b0mbtrack]

I have a v-6 carbed mercruiser inboard but will have to get back on the model number and year but I believe it is from the 80s. It uses points. I did the oil change already and did the fuel filter. It runs real smooth and doesnt miss a beat up to 4000rpms but when you give it a little more throttle it quickly drops down to about 3000rpms. It will stay running at this point but then when you pull back slightly on the throttle it will go back up to 4000rpms. I thought it would be the carb so I took it apart and cleaned it out but am having the same issue. I'm going to go out with a buddy tomorrow to see if the secondaries are opening or not but figured I would come here too and see what anyone else might think.

I know I didn't do the tune up yet but it didnt seem like a spark plug/points kind of issue. Any help would be appreciated, thanks.

 

[alldodge]

Re: Mercruiser running poorly above 4000rpms

I have a v-6 carbed mercruiser inboard but will have to get back on the model number and year but I believe it is from the 80s. It uses points. I did the oil change already and did the fuel filter. It runs real smooth and doesnt miss a beat up to 4000rpms but when you give it a little more throttle it quickly drops down to about 3000rpms. It will stay running at this point but then when you pull back slightly on the throttle it will go back up to 4000rpms. I thought it would be the carb so I took it apart and cleaned it out but am having the same issue. I'm going to go out with a buddy tomorrow to see if the secondaries are opening or not but figured I would come here too and see what anyone else might think.

I know I didn't do the tune up yet but it didnt seem like a spark plug/points kind of issue. Any help would be appreciated, thanks.

Sounds to me like the secondaries are opening but no more fuel is coming. Maybe a clogged passage, float level set to low or fuel pump. Think most likely problem is clogged passage.

 

[b0mbtrack]

Re: Mercruiser running poorly above 4000rpms

Ok, maybe I missed something in the carb. it won't hurt to give it another try. I didn't mess with the float height but maybe it was off for some reason so I'll check that too. I have actually done so many carbs over the years and don't think I've ever adjusted a single float height and never had a problem so this might be a first. Thanks for the reply. Ill update how I make out.

 

[FreeBeeTony]

Re: Mercruiser running poorly above 4000rpms

You can also try running off a seperate tank to rule out anything from the tank back..........