85 TS6M no spark

[suprats6m]

Hey guys, I have been rebuilding a TS6M for the last 4 months (I know it was bad timing to work on a boat but not really an option to do it in the winter). so far this forum has been super helpful with the whole process. I replaced the stringers and floor and have everything back together. last obstacle to conquer is the ignition system. I have been able to find pretty much everything i needed on the forum, but cannot figure this out, and any help would be much appreciated. I have the engine cranking but not turning over. i have confirmed there is fuel but no spark. I replaced the points system with a pertronix kit and flame thrower coil. still no spark so it must be in the wiring. I have not touched the wiring and it has run previously (before i started tearing it apart to redo the stringers). I have tested every I know how to test and the last thing i will try tonight is swapping the 40A breaker. does this breaker run through to the coil or is it just for the starter motor? Anybody have any other ideas on what it could be? I have replaced the distributor, coil, solenoid, starter, fuel pump, and carburator in the past 3 years. also the engine is a pcm 351w

[michael hunter]

Too much to wright call me when you are at the boat . Make sure you have a test light and a volt meter when you call. Mike Hunter 678-227-8833

[suprats6m]

I tried calling yesterday after work but must have missed you. I did check the voltage at the coil, 7-8 volts in the on position and 4.5 when cranking. There is a brand new coil and distributor. Any ideas why that might be the case? Battery also showed 12.5 volts

[etktryd]

I believe the stock wire is a resister wire. All the electronic or pointless dist I have installed recommend you run a new wire off the key that delivers full batt. voltage.
Check your instructions !!!!!!

[etktryd]

Even with the resister wire you should have 12 volts on cranking !!!!! Check voltage at the switch. Run a jumper wire from the batt to see if she will fire. If she fires you will have to unhook the jumper to stop the engine.

[michael hunter]

Connect a jumper wire from batt positive to coil positive . If it starts work backwards to find the cause of the voltage drop.

[lmnelson86]

I had a similar issue earlier this year, turns out my tach had a bad resistor inside, it as robbing me of all of my power. Unhook the grey wire from your coil to tach and see what happens. I found it by an absolute fluke, someone at a bar overheard me bitching about my boat and was a marine mechanic and told me to check that...sure as the skys blue it fired right up.

[etktryd]

Good call !!!!!
I had this happen with an HEI distributor. The tach fried the pickup coil. Would run for 15min. then just die.