Can I convert my 1973 Mercury 1500 to distributorless?

[DirtyOldBoat]

I'm trying to fix up my 1973 Mercury 1500 - I have a new rebuilt powerhead, but most of the electrical stuff on the motor is either bad or suspect...as is my power trim. I found somebody selling a complete 1979 115hp motor that has a bad powerhead but new electrical stuff, and it's super cheap.

Can I convert my 1973 powerhead to use the distributorless ignition system if I have an entire outboard to pick from? Will the parts all bolt up? I guess the question would make more sense if I said I was putting a 1973 powerhead on a 1979 motor...

 

[Faztbullet]

Re: Can I convert my 1973 Mercury 1500 to distributorless?

Can I convert my 1973 powerhead to use the distributorless ignition system if I have an entire outboard to pick from? Will the parts all bolt up? I guess the question would make more sense if I said I was putting a 1973 powerhead on a 1979 motor...

It can be done but its not worth the efforts. Making brackets for ignition plate, relocating fuel pump ,installing the front half of the later model motor and milling crankcase ends flush to match your block and time/hassle not worth it. I did it once but not again but the real answer is should be no

 

[sourbsted]

Re: Can I convert my 1973 Mercury 1500 to distributorless?

I always wondered what was involved with this conversion. I copped a lot of flac off outboard machanics for buying an older inline, I guess a wornout dizzy shaft is the only downer in time t for having one.

 

[DirtyOldBoat]

Re: Can I convert my 1973 Mercury 1500 to distributorless?

Hmmm...how about the power trim cylinders? Will they swap? Mine are leaking. Starter? Stator? I know the stator has extra wires for the newer ignition, can I ignore them? I think I'm going to grab it anyway for $150...I know I can ebay the parts for way more than that.

 

[Chris1956]

Re: Can I convert my 1973 Mercury 1500 to distributorless?

PTT was the same for quite a few years. You need the two cylinder, external pump and 4 hydraulic line type PTT.

Your original Stator is two wires, not the 6 or more wires of the ADI type stator, so they are incompatable. If you have an ADI stator, I am not sure of the effect it will have on your charging system.

Your Starter is likely the old style with the vertical brushes. Newer starters have the flat, horizontal commutator.

 

[DirtyOldBoat]

Re: Can I convert my 1973 Mercury 1500 to distributorless?

Was 1979 the first year for the distributorless motors? I finally talked to the seller, and he says it actually does have the distributor. Hoping to pick it up tomorrow...

 

[Georgesalmon]

Re: Can I convert my 1973 Mercury 1500 to distributorless?

I have a 1979 115 in line and it does not have a distb.

 

[kazek]

Re: Can I convert my 1973 Mercury 1500 to distributorless?

ptt cylinders can be rebuild for less than a coffee.starter motor ussually needs cleaning and a new brushes and/or plate.wireing is ...well...bad on 70's motors,and in most cases can be replaced.

 

[Chris1956]

Re: Can I convert my 1973 Mercury 1500 to distributorless?

DOB, 1979 marked the transition from distributor ign to ADI for IL6s. Early '79 motors were dissy...

 

[sludgeguy68]

Re: Can I convert my 1973 Mercury 1500 to distributorless?

DOB, 1979 marked the transition from distributor ign to ADI for IL6s. Early '79 motors were dissy...

I have a 1400 serial #4867256 which seems to place it in 1978, but there is no dizzy. Two switchboxes and a coil for each cyl... wonder if power head was swapped by a PO. It doesn't look cobbled together though.

 

[Chris1956]

Re: Can I convert my 1973 Mercury 1500 to distributorless?

Sludge, Crowleymarine parts catalog shows both serial groups of the 140HP motor from 1978 have a distributor. That cooresponds with my memory. Maybe your powerhead is a year or two newer? There is a part number on the block, about 1/2 way up the transfer port side. You might check it out.

 

[Faztbullet]

Re: Can I convert my 1973 Mercury 1500 to distributorless?

Look on your front cowling support sludgeguy68 and it will give timing spec and should say 1978 or will actually be marked 1979 1/2 on decal.

There is a part number on the block, about 1/2 way up the transfer port side. You might check it out.

part number wont mean much , look at boss and if it has the matching serial number it hasnt been changed and you got a 79 motor on a 1978 mid from factory...

 

[sludgeguy68]

Re: Can I convert my 1973 Mercury 1500 to distributorless?

Tell me I have a 115hp powerhead :facepalm:


That would explain my lower-than-expected speed on the water. I guess it's a 1979 115 on a 1978 140 mid, that would make sense, sorry bout that, and thanks for telling me where to look!

 

[DirtyOldBoat]

Re: Can I convert my 1973 Mercury 1500 to distributorless?

SCORE!!!!!


$150. Including the cowls, trim pump, and throttle control. And a NEW stator! And a NEW distributor trigger. And a NEW wiring harness. And new plug wires. All stuff I needed!! The powerhead is seized, but I have a new one.

Miracles do really happen!

 

[DirtyOldBoat]

Re: Can I convert my 1973 Mercury 1500 to distributorless?

Are the 115 carbs the same as my 150? I don't "need" new ones but they look so clean!!

 

[Chris1956]

Re: Can I convert my 1973 Mercury 1500 to distributorless?

DOB, That motor is a '76 or '77. I think your '73 1500 may be different in the internals, exhaust porting etc., but don't really know for sure. Some of the IL6 experts should chime in on that.

 

[Faztbullet]

Re: Can I convert my 1973 Mercury 1500 to distributorless?

That would explain my lower-than-expected speed on the water. I guess it's a 1979 115 on a 1978 140 mid, that would make sense, sorry bout that, and thanks for telling me where to look!

No difference in motors as the 140 was PH rated and later 115 was prop rated ..both put out about 120hp at prop.

Are the 115 carbs the same as my 150? I don't "need" new ones but they look so clean!!

Not the same as as difference in venturi and metering tubes. Your 150 will have a power port block and pistons but the 115 will not.

 

[Laddies]

Re: Can I convert my 1973 Mercury 1500 to distributorless?

Aren't the reed blocks different.

 

[GCarlover]

Re: Can I convert my 1973 Mercury 1500 to distributorless?

I've been reading all your posts. Very interesting. Is your parts store open for business yet? Don't forget premium fuel. That could have burned up some of the motors. Ask about timing setting; may help. The 70-71s had a high setting. Burned a piston pulling a hard slalom skier. You won't hear them ping. Check the main swivel bushings, had to replace when I had the 115. Also the older Mercs had a different tach. Used ign pickup. Most later models went to alternator pickup. The battery plug-in wiring harness used to corrode; voltage loss, weak spark, hard starting. Merc hp at the shaft in 82-87. Jonson rated propshaft hp 85 and up. So a 140 became a 115 in 1982. The 76-77 150 xs (vented cowl) was rated to 6000 with a aluminum flywheel and something else? 73-77 to 5800 rpm.

 

[Faztbullet]

Re: Can I convert my 1973 Mercury 1500 to distributorless?

The 76-77 150 xs (vented cowl) was rated to 6000 with a aluminum flywheel and something else?

The 150XS had a different block(porting),reed block,carbs,tuner and lower unit housing(lower water intake) other than that it used stock parts and never had a aluminum flywheel from factory, only the T2 and Twisters had factory aluminum flywheel but they will interchange.