Hooking up spark plug wires on cap

[AL350SEARAY]

Thanks in advance. my engine is a mcm 255 350cid gmc serial #5375179. I bought this boat last year and only did small maintainance like changing motor oil, lower unit oil, fuel water separator and oil filter. It ran fine all summer. This past winter and spring I replaced water hoses, impeller, thermostat, plugs,wires,and went through carb as well as the same maintainace as the first year. First time in the water it ran fine up to 1500 rpm then it bogged down. It does not turn off it just will not throttle up. Thinking i messed up the carb rebuild i purchased a new quadrajet carb from a place i found a link for here on these forums. Same problem. Took it to a shop and they told me the mechanical fuel pump was not working properly so i bought and installed a new one. Same problem. Now turning my attention to the engine internals i checked compression and found a dead cylinder. when i took the valve cover off i found that the rocker arm on the dead cylinder had fallen off of rod. thankful to of finally found the problem i fixed it, adjusted all the rocker arms and put it back together. when i tried to start it the engine had no spark. i went and bought a rebuild kit for my electronic distributor, cap, and ignition coil. now it starts but i still have the same issue as before. nothing above 1500 rpms. when i was messing with the distributor i noticed the wires were not in proper sequence and the number 1 spark plug wire was not lined up with rotor when engine was at #1 tdc. it is completly on the opposite side. when i changed out the wires i did them one at a time so it is the same order as last year and it does start right up and run. when i tried to set them in correct sequence starting with where the rotor was at tdc the engine would not even start. i am sorry if this post has been extremly long. any help would be greatly appreciated.

 

[Bt Doctur]

Re: Hooking up spark plug wires on cap

Start at the beginning. remove valve cover .locate #1 intake rocker. Rotate motor untill valve opens and closes, continue turning motor untill timing mare on balalcer is at "0". remove dist cap, look where rotor is pointing. that position is #1 TDC ,compression stroke. Should you wish to do it correctly, reinstall dist with rotor facing the lug on the cap for #1 plug. . put #1 wire there and go 1,8,4,3,6,5,7,2 in a clockwise direction on the cap.

 

[AL350SEARAY]

Re: Hooking up spark plug wires on cap

THANK YOU FOR YOUR RESPONSE. I HAVE TURNED ENGINE TO #1TDC THE WAY YOU DESCRIBED. THE ROTOR POINTS TOWARD FRONT OF ENGINE. THE CAP ITSELF HAS NO MARK FOR #1 PLUG WIRE. DO I HAVE TO REMOVE ENTIRE DISTRIBUTOR. THE WIRE GOING TO #1 CYLINDER IS ON THE SIDE OF CAP TOWARD BACK OF ENGINE. I TRIED STARTING ON THE STUD THE ROTOR WAS POINTING TO AT TDC AND GOING AROUND CLOCKWISE USING SEQUENCE YOU SUGGESTED BUT THE ENGINE WON'T EVEN START. AGAIN THE ENGINE DOES START AND RUN THE WAY IT IS NOW,BUT I KNOW IT IS WRONG AND COULD BE THE CAUSE OF MY NOT BEING ABLE TO THROTTLE UP PAST 1500RPMS. ALSO THE WIRES ARE NOT IN THE SEQUENCE SUGGESTED WHEN IT STARTS AND RUNS. COULD IT BE A TIMING ISSUE. IT JUST DOESN'T MAKE ANY SENSE TO ME THAT THE ENGINE WOULD START AND RUN WITH THE WIRES SO FAR OUT OF WACK.

 

[AL350SEARAY]

Re: Hooking up spark plug wires on cap

Okay. Checked timing while it was running with wires hooked up wrong and it was way off. (advanced almost 80 degrees) started turning distributor back towards
zero and it started running bad then turned off a little before i got to zero. It would not restart. I figured if it wouldn't run with the wires hooked up that way anymore it might run if i hooked them up the right way. I tried it and it cranked right up. My question now is where should i set the timing at with the engine at idle. At "0" or 8 btdc like it says on the engine. Thank you again for any input.