43 wonbt start

"hello, we are new to the powe

"hello, we are new to the power boating world, we just bought a used ('87) deck boat with a 4.3 i/o, the motor started right up when we bought it. and when we got it home ,about a 90 mile drive ,it didn't have any power and stalled a few times so I checked to make sure it was getting gas, everything fine there, no water in fuel or bad gas ,then i used some carb cleaner and it was still running as i let it warm up it started missing then it shut off on its own and wouldn't restart,it turns over but won't fire after more checking we found we didn't have any spark at the plugs we did a test to the coil and it looks like the is power going in but not coming out any ideas besides a coil that would cause these problems
Thanks"

"Point type ignition system???

"Point type ignition system??? If so, check for closed points and a rusty or dry distributor cam causing the rubbing block to wear and the points to go out of adjustment."

"Carefully remove the high ten

"Carefully remove the high tension lead from the distributor cap and ground it against a solid engine part. Crank the engine over and see if there's any spark between the lead and the engine. If there is no spark, and it's a conventional ignition system,(which at that vintage I believe that it is), I'd look to the coil. If there is a spark, continue into the distributor as previously advised.
When you say that "it didn't have any power", are you refering to battery power? If so, check all of your electrical connections (battery terminals, ground wire, ignition wiring, etc.) to make sure that they are sound."

"Tests for Thunderbolt Ignitio

"Tests for Thunderbolt Ignition:
W/ignition key on AND BILGE WELL VENTILATED OF GAS FUMES!!!

#1 - Connect your voltmeter neg. lead to the engine ground and pos. lead to the white/red wire terminal at the dist. It should read 12 volts.

#2 - If 12 volts is present, remove the coil spark wire from the distributor and connect it to a spark gap tester to ground. Remove the white/green lead from the dist. terminal. Turn the ign. key to on and strike the white/green lead to ground. If there is spark, replace the ignition sensor in the dist.

#3 - If there is no spark, substitute a new coil and repeat test #2. Now if you get spark, install a new coil. NO SPARK, replace ign. amp.

#4 - In #2, if there is No voltage present, disconnect the white/red wire and check it again for 12 volts. If 12 volts is present, replace the ignition sensor inside the dist. cap. If no 12 volts present w/it disconnected--ignition amplifier is shot and must be replaced."

how hard is it to replace the

how hard is it to replace the ignition sensor inside the distributor? that is my problem

Not hard at all. The rotor is

Not hard at all. The rotor is Loctited in place and may need to be split w/a chisel and hammer to remove. First grab it on the side from the top and twist and pull w/a channel lock pliers. Disconnect the battery and have at it.

Reset the engine timing when done.

"thanks for all the help,after

"thanks for all the help,after some more checking we found that the whole fuel system is wrong on the boat ,it has an automotive fuel pump rubber hose and is wired up to the coil,we took it back to the dealer we bought it from and they are fixing it right,they should not have sold it to us this way
thanks again this is a great site"