distributor not always rotating with engine

wendellbee

Seaman Apprentice
Joined
Sep 3, 2014
Messages
31
i installed a new pertronix electronic dizzy along with a new coil and newer wires and plugs. i have noticed that the dizzy does not always turn when i was bumping the motor, using the starter, to get it to TDC.
i was able to get it to start one time (I shut it down since it's a marine engine and i did not have a water source hooked up). further attempts to start it were unsuccessful, so i rechecked timing and noticed that the dizzy, every once in a while would not turn when i was bumping the starter to get it back to TDC. the engine crank would rotate but not th dizzy. this caused the rotor to be out of position (not on #1 cylinder) when i got back to TDC. Is this caused by me bumping the starter or is there something else wrong. i tried this a few times and i'd say 80% of the time the rotor was positioned correctly but the other times the rotor was way off even though the pointer was at 0 . I tried turning by hand but it's difficult given the confined space (twin 460 inboards and the pulley has a raw water pump in the way). the previous dizzy was broken when i purchased the boat so i can't say if it had any issues.
 

jerryjerry05

Supreme Mariner
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May 7, 2008
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17,926
Measure the shaft on the new .Compare to the old.
Inspect the teeth on the cam where it meets the dist.
 

gm280

Supreme Mariner
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Jun 26, 2011
Messages
14,590
If the distributor is the correct length and the gears are meshing properly, look for a roll pin missing at the gear end. Because there would be no way to keep the gear firmly attached to the distributor shaft... JMHO!
 

wendellbee

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Sep 3, 2014
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31
thanks guys, i removed dizzy and roll pin is still present. replaced it ,making sure it was seated and cranked motor. got a couple of sputters and exhaust from the risers. after a few attempts engine sounded like it was turning faster so looked at dizzy and it wasn't rotating at all. dizzy is okay so i think it's a timig chain/gear issue. won't be able to do anything until this weekend, provided weather is a little cooler. no better way to lose weight than working in the bilge in 90 degree heat
 

gm280

Supreme Mariner
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Jun 26, 2011
Messages
14,590
thanks guys, i removed dizzy and roll pin is still present. replaced it ,making sure it was seated and cranked motor. got a couple of sputters and exhaust from the risers. after a few attempts engine sounded like it was turning faster so looked at dizzy and it wasn't rotating at all. dizzy is okay so i think it's a timig chain/gear issue. won't be able to do anything until this weekend, provided weather is a little cooler. no better way to lose weight than working in the bilge in 90 degree heat

Ha, seriously, be careful in the heat. I know what heat stress can do to you... Also post back here to what you find. Any time the distributor is not moving when the engine is, it is time to stop trying and find the cause. I have see gears stripped out on distributor shafts and even roll pins sheared. So let us know...
 

wendellbee

Seaman Apprentice
Joined
Sep 3, 2014
Messages
31
Checked valves this weekend and none are moving. Removed dizzy and shear pin still good plus gear doesn't look like it was chewed up or anything. My confusion is the timing chain and gears. I see different sets stating straight up or 4 - 8 degeees retard. How do i tell which one i have or need.? There is no vacuum advance .
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Jul 23, 2011
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47,491
I would install a double roller timing chain. most of them have 3 key locations, straight up, 4 degrees advanced, 4 degrees retarded. your motor most likely came straight up from the factory if your older than 1972, or 4 degrees retarded if after 1972.

I would probably do both motors, and in your case of twins, probably pull them. you may be able to get away without removing the pan with a timing set kit, however I personally like to change the pan gasket at the same time.
 

Bondo

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Apr 17, 2002
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70,506
Ayuh,.... What Motor,..... There may not be a chain,....
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
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Jul 23, 2011
Messages
47,491
Bondo, he states twin 460's. He did not state a year
 
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