newbie with no clue merc 500 questions

[toytech]

ok guys. my name is shawn im from nh. i just got a 1990 gw invader 10 footer. wicked cool boat. so i bought it knowing it hasent been run in years. major four generation mouse condo on the engine. bunch of wires chewed up etc. i evicted the tenants and repaired the wires cleaned the carbs. i needed to put a new belt on the dist that was broken. theres no spark. has good compression in 3 of the 4 cylinders. cant get to number4. will the belt being out of time not allow the boat to have spark. i thought it would spark but be at the wrong time. i have no repair manuel and the local dealer has brought theres home.... lol. any insight please?

 

[toytech]

Re: newbie with no clue merc 500 questions

i think the engine is a 1973 500 50hp mercury 4 cyl thunderbolt.

 

[toytech]

Re: newbie with no clue merc 500 questions

here it is. i need to cruise this thing!!!

 

[toytech]

Re: newbie with no clue merc 500 questions

Come on guys. Wheres all the die hard merc techs?

 

[james33]

Re: newbie with no clue merc 500 questions

i have a similar motor on a 13 foot ski boat... be careful! if its not sparking at all im willing to bet your coils are shot!

 

[toytech]

Re: newbie with no clue merc 500 questions

how do you test the coils? it looks like it only has one. what should i be careful off:?

 

[79Glastron]

Re: newbie with no clue merc 500 questions

Hold the phone there buddy. With no belt, you will NOT have spark. The ignition system is called lighting energizer, it generates its own power to power the switch box and fire the coil. You'll need a special tool to remove the flywheel to install the belt, make sure you align the timing marks on the flywheel and the arrow on the distributor pulley. I own a `70 and `75 Merc 500, basicly same as yours.

 

[toytech]

Re: newbie with no clue merc 500 questions

i put a new belt on. no manuel. heres how i timed it... i put cyl 1 at TDC, there was a double mark on the fly wheel assebbly. under the cover of the distrubuter there was an arrow. i amed them at each other. was this correct?
still no spark. kind of messed around with it yest...

 

[carholme]

Re: newbie with no clue merc 500 questions

tech;

You don't mention your s/n anywhere so saying it is a 1973, here is a condensed version of the Clymer service manual. Maybe it will help you.

Let the page load for 30/40 seconds:

http://web.ebscohost.com/serrc/pdf?...9239-9b9c846e2aca@sessionmgr111&vid=4&hid=119

Gerry

 

[CharlieB]

Re: newbie with no clue merc 500 questions

Download the free Igniton Troubleshooting Guide from the Support pages of CDIElectronics

Follow the detailed directionsw to test the system.

The early Battery CD distributor system has both a constant 12 v lead and another 12 v lead switched on thru the igniton switch, either fail and no spark.

 

[toytech]

Re: newbie with no clue merc 500 questions

appears to be a 72? s/n 3348406

 

[79Glastron]

Re: newbie with no clue merc 500 questions

No battery required for spark. Are you cranking it with the key switch? Remove the two other wires from the second from the top termial on the switch box, leave the wire coming from the distributor. Crank and check for spark. If none, do a switchbox test, look on max rules website.

 

[jeffreyr]

Re: newbie with no clue merc 500 questions

Yea i was gonna say..Test the switchbox..I had a problem with my top coil not firing and it was the switchbox..

 

[CharlieB]

Re: newbie with no clue merc 500 questions

Sorry guys, distributor motors do not have multiple coils or switchboxes.

The distributor models used an igniton 'amplifier', an electronic switch that increased the dwell time between trigger events to maximize coil saturation time. These units do not work intermittantly, they either work or they don't.

Intermittant igniton failue on these are either a poor power contact in the igniton switch, wiring harness cannon plug, or the distributor trigger beginning to die.

Tests are well outlined in the CDI Ignition Troubleshooting Guide.

 

[79Glastron]

Re: newbie with no clue merc 500 questions

Sorry guys, distributor motors do not have multiple coils or switchboxes.

The distributor models used an igniton 'amplifier', an electronic switch that increased the dwell time between trigger events to maximize coil saturation time. These units do not work intermittantly, they either work or they don't.

Intermittant igniton failue on these are either a poor power contact in the igniton switch, wiring harness cannon plug, or the distributor trigger beginning to die.

Tests are well outlined in the CDI Ignition Troubleshooting Guide.

Are you talking about the lightning energizer ignition system used on the 500 motors? All the parts look ups I have ever seen called the "box" a switchbox. Whichever the case, the switchbox can be tested, the high and low coils can be ohmed out for spec and the SINGLE coil can also be checked. Again, no battery power required. I'll have to find it, but there is a simple test for the swithbox using the diod tester selection on a DMM, or a simple continuity tester would also work. One could also check DVA from the ignition driver (distributor), specs should be easy to find.

 

[toytech]

Re: newbie with no clue merc 500 questions

i at one point put the red wire from the rectifier that has power with key on to the blue box on the switch box when i was repairing wires. more then likly i fried that box for starters. i now have a service man and wiring diagram.

 

[toytech]

Re: newbie with no clue merc 500 questions

merc switch is not connected currently

 

[79Glastron]

Re: newbie with no clue merc 500 questions

i at one point put the red wire from the rectifier that has power with key on to the blue box on the switch box when i was repairing wires. more then likly i fried that box for starters. i now have a service man and wiring diagram.

Yeah, that probably wasn't good for the switchbox, still, do the test for the box. If it fails, you can get them on ebay, some places I've see take yours and rebuilt them and sent it back out. I have two good ones for spares myself, for that rainy day.

 

[toytech]

Re: newbie with no clue merc 500 questions

charlie where can i find the trouble shooting guide?

 

[toytech]

Re: newbie with no clue merc 500 questions

glastron where can i find the test for the switch box? sell me one of your spares???????