please hepl me not hang myself

[502procharger]

this is my original post
ok, i was setting up a procharger on my boat (502) , the carb i had for the system ran ok but was a bit lean in a few spots. i am having nickerson build me a carb, and will not have it for a week or so. i removed the carb box for the procharger system and replaced it with my old carb. i left the areomotive fuel pump i had installed for my procharger and just reduced the pressure to about 7-8 pounds. It starts, runs, and revs fine. As soon as I put it in gear( under load) it spits sputters, backfires and pretty much will not even run. if i do get it to stay running i can only idle, or a bit above or it backfires. what the hell is going on? did i knock a wire loose? i messed with different fuel pressures, but nothing helps. it would be a great running boat if i just never put in into gear. please give me some advise. if anyone out there has a msd ignition for sale for this 502 please let me know
So, i have since after many good ideas from all of you guys done all of the following. replaced my power valves, plugs, wires, diff. carb, coil, checked all conections and grounds. Nothing has helped. motor runs perfect until it is under any load. what i did find is that the 2 ground wires to the neg side of my coil were flopping around, the nut had backed almost all the way off. I thought for sure i found the problem. NO, still the same shit. i hooked a timming light up today and found some interesting stuff, first the timming moved around a bit, next after a min or so i started to get the timming light flashing "off" (not smooth, it would miss a flash or two. what the f#%* is going on. i am pretty sure my neyt move is to replace the entire system with an msd. any ideas on what to check, or how to check my thunderbolt system please let me know. 12 pack, and a ham sandwich to anyone who can fix my problem.

[BOFH]

If your timing wanders, you have a problem in the distributer. This could be rust advance weights and springs or it could be a worn shaft. The way to check the shaft is easy; grab the rotor, and jerk it back and forth. If it moves at all, the distributer is junk.
Frankly, with the money you are spending already, just buy a new ignition system and distributer. (The MSD distributer is NICE) It may not be your only problem, but your engine could use a premium ignition system and electronic distributer.

[gnarley]

Pull out the dist & check the roll pin in the gear if it is sheered it will reek havoc & do everything you are explaining even check the rotor & it better not move from side to side at all.

[502procharger]

ok, cap and rotor are new about 5 hrs ago, both look great, but who knows. replace wires, i do have a thunderbolt IV, it is an electronic ignition, not points. i replaced the pickup in the distributer today ( just happen to have a spare) i had my buddy at a marina pull a few thunderbotlt control boxes of the same year boat and bbc and swapt them for mine, no f%3@ing differance. my plugs look really dark except for the strap, that is clean. if i run it at 1000 rpm's it raises and lowers by 50-100 each way and you can hear the motor start to run a bit better then worse. i am not sure now that the timming is jumping around, i think i was just cutting through my timming light wires with my belts( what can i say, i am retarded). i know i said i thought it was electrical, and i still do, i have replace the carb, and rebuilt one, both do the same thing. is it possible it is still fuel related? god i went as far as to spray my motor down with a hose while it was running to see if it quit because of a loose, or grounding conection. no change just ran along. the only time that this boat has run right lately is when i had the procharger hooked up. i am still waiting for my carb back from nickerson, so i can;t even try that. i need to buy a row boat with a 1964 9.9 merc out board. any mor ideas guys?

[502procharger]

do you think i can put my procharger on that?

[gnarley]

Have you opened this carb up & looked inside for any obstructions or blown it out while open? it just takes a small piece of crap to ruin the idle & part throttle circuits.

[502procharger]

holy shit. just for giggles i put a 2nd new set of plugs in the boat and a 2nd new cap and rotor. low and behold, it lives!!! nickerson called today and i will have my new carb for my procharger for the weekend. now lets see how long before i blow the motor or drive. I REALLY WANT TO THANK EVERYONE!! I OWE YOU ALL A BEER. Truthfully it is hard to find a better bunch of people then boater! thanks again