87 civic loses power on interstate or going up hill

[lv2snwbrd]

I have a 1978 civic 1.5 with a carb'd engine. It seems to be loosing power at higher speeds (even slows down) or when going up hill. I have changed the fuel filters and done a tune up on it. Have a new PCV valve but not sure where it is located under the hood. It is also fouling out spark plugs really fast. When I change them they have some type of black build up on them, oil maybe? Just not sure where to start. Have a haynes manual and am pretty comfortable doing work myself. Never messed with a carb though. Any help is appreciated.

[jwaj2002]

replace the muffler, and the cat converter,

[ecobwg]

Sounds to me like its running way too rich.

[lv2snwbrd]

Can you adjust that without any special tools? Also, would the carb running rich foul my plugs and leave black deposits or would that only be caused by bad valve seals?

When I gas it in fourth or fifth it just feels like it is flooding the engine and loses power. Fourth normally won't get above 3500 rpm's and fifth I'm doing good to get 3000. Thanks for the tip.

Lv2

[cvcc_wagon]

running rich would leave some deposite of unburnt fuel however leaky valve seals would do the same thing. firstly, is it an 87 or a 78? do you get a puff of smoke when iy first starts up? what is the condition of air intake hose off the carb hat?

[lv2snwbrd]

Well guys here's a little update for you. Kind of embarasing. turns out my civic is an 86 not a 87. I now have the right spark plugs in there and it seems to be running fine. I will give it a couple days and see if it keeps going good. Is it possible that the 87 spark plugs (bosh platinums) were getting to hot and burning up?