New to me engine...what do I have

[cocacola]

I am not sure what I just bought....
This number is on the block 716358
might be other numbers.

please let me know that I have

More pics if that helps

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[cocacola]

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[rumleyfips]

71 is a Mark 15 serial number. At one time they were the hot ticket. Probably a Mark 15 power head on a real early marathon lower. The pipe could be for mod, alky or just play.

[cocacola]

thank you!!!!!

[cocacola]

thank you!!!!!

I got all of this for $150

Good or bad deal?

[Ketzer]

If you let those spiders on the lower unit bite you, I'd say you got a bad deal, but otherwise, free of bites and as such art is priceless, you got a great deal!

[DeanFHobart]

thank you!!!!!

I got all of this for $150

Good or bad deal?

The most expensive part of what you bought is the gear case. Assuming the gears are good complete gear cases are worth up to $1000….. Take the gear case off the tower housing, drain all the oil or grease out and put in new gear oil. Roll the gears over and feel that there is no binding or or ‘catching’. Also remove the rear cone bearing assembly…..rembering the threads for that are left hand threads, so to loosen the cone by turning it clockwise. There are special tools for that you need to get.
The next expensive part is the tower housing…… it is a Q model…. Mercury later came out with what was called the ‘hydro short’ tower housing. All of the interior parts for the gear case are available new…..gears, prop shaft, beatings, seals, water pump parts and rear cone and bearings. The parts for the Bendix magneto might be hard to find. Assuming that you want to turn it back into a stock motor….change the pipe setup to the stock exhaust plates. And discard that ugly steering bar and find a stock chrome one.

Good luck in your venture. Of course you will need to get the rewind parts. But you did get a good deal at $150.

[zul8tr]

Dean is correct on the gear case and tower that have worth. Also the prop is worth prob $50 and the transom clamp assembly has value if the forged alum design not the cast alum design. If you take off the gear case cone using the right tool do it with the complete engine mounted on a stand for better control, repeating Dean's advice to remove turn clockwise viewed from the rear, it might be really stuck? Once removed there is an inner cone piece with bearings or just a bushing sleeve if the older design. If bearings are present they are lubed separate from the lube of the gear case and have their own lube requirements, prop shaft condition very dependent on how well these bearings were maintained.

When you do hand test the gear case pull up on the drive shaft as you rotate it - they are designed with some vertical bearing clearance -you should not feel gears meshing for a good 1st test. If you want to look into the gear case to see gears there is another special tool to pull the water pump cartridge.

It appears you got a good deal at $150

Let us know what inspection reveals

[cocacola]

thank both of you for commenting. Great information and it makes me think that the guy selling wanted to start at $1000. Something told me it was just a negotiating technique and he knew nothing more than me.
I will enlist my dad's help as he raced engines like this in the 50's....but mainly the 30H.

Last night I scrubbed and pressure washed the whole thing. The coated the entire think in a film of oil.

Also....I sprayed some starting fluid in the cylinders and it fired up.

Since my DAD (https://www.boatracingfacts.com/forums/showthread.php?765-Lone-Star-Boat-Racing-Association/page20) (see my post about him) is 250 miles away....I'll do what I can before getting him involve.

[cocacola]

thank both of you for commenting. Great information and it makes me think about the guy selling wanted to start at $1000. Something told me it was just a negotiating technique and he knew nothing more than me.
I will enlist my dad's help as he raced engines like this in the 50's....but mainly the 30H.

Last night I scrubbed and pressure washed the whole thing. The coated the entire think in a film of oil.

Also....I sprayed some starting fluid in the cylinders and it fired up.

Since my Dad is 250 miles away....I'll do what I can before getting him involve.

see this post about him
https://www.boatracingfacts.com/forums/showthread.php?765-Lone-Star-Boat-Racing-Association/page20


Pictures
https://www.dropbox.com/scl/fo/csqqushtevxcfnbwe9501/h?dl=0&rlkey=39wpc8vs64az1m5hlz3my8dk9

[cocacola]

Hi Dean. As you probably know by now...I am good friends with a friend of yours....Tom Williams.

[cocacola]

The most expensive part of what you bought is the gear case. Assuming the gears are good complete gear cases are worth up to $1000….. Take the gear case off the tower housing, drain all the oil or grease out and put in new gear oil. Roll the gears over and feel that there is no binding or or ‘catching’. Also remove the rear cone bearing assembly…..rembering the threads for that are left hand threads, so to loosen the cone by turning it clockwise. There are special tools for that you need to get.
The next expensive part is the tower housing…… it is a Q model…. Mercury later came out with what was called the ‘hydro short’ tower housing. All of the interior parts for the gear case are available new…..gears, prop shaft, beatings, seals, water pump parts and rear cone and bearings. The parts for the Bendix magneto might be hard to find. Assuming that you want to turn it back into a stock motor….change the pipe setup to the stock exhaust plates. And discard that ugly steering bar and find a stock chrome one.

Good luck in your venture. Of course you will need to get the rewind parts. But you did get a good deal at $150.

any leads on a steering bar like you mentioned?

[zul8tr]

Nice pics and great it fired right up. Did you have the gear case in a water barrel to see if it pumps or just a dry start for now? Again you got a great deal!

[cocacola]

Nice pics and great it fired right up. Did you have the gear case in a water barrel to see if it pumps or just a dry start for now? Again you got a great deal!

let me clarify.....not in the water or water bucket.
Just finished cleaning it up and sprayed starting fluid spray into spark plug holes.
Then I pulled rope, it made a firing sound and smoke came out of exhaust.
EXTREMELY BRIEF run.....a second or two.

Lets see how much time I have this weekend....
My guess is fuel pump isn't working.
NOTHING has been opened up (carb and pump).
Who knows how bad the water pump is....my ONLY experience is a 115 inline and 200 V6.

I'll have wife ready with video camera next time:)

[zul8tr]

From pics were those 2 different J6J and H10 plugs in the engine? Not sure where H10 heat range is relative to J6J which is hottest in the 3/8" reach design. If you plan on barrel running it get new plugs J6J, if you go this way on a race boat at high speed need colder like Champ J4J would be preferred?

[cocacola]

From pics were those 2 different J6J and H10 plugs in the engine? Not sure where H10 heat range is relative to J6J which is hottest in the 3/8" reach design. If you plan on barrel running it get new plugs J6J, if you go this way on a race boat at high speed need colder like Champ J4J would be preferred?

Yes....plugs were not matching.
Thanks for advice....I cleaned them but clearly worn out.
I did spray a LOT of oil in cylinders.
Did not take a compression test, but seemed strong....something else to do this weekend.

[zul8tr]

A compression test with lots of oil in the cylinders will mostly give a high unrealistic psi reading. I do a compression test with residual gas oil mix and get readings and then squirt some oil, rotate crank several times to distribute and compare to not loaded with oil. Results always higher in latter case. I always to it cold at similar ambient temp to eliminate the temp variable and keep track of cold values. Doing compression check over time is important for the relative changes to engine not so much for absolute psi values, but low compression not good, I always use the same gage. For your engine I would think 120 psi and close to that (say 5psi max difference acceptable) in both cylinders is ok. I always keep track of each rope over compression value up to max, should get max in 4 to 5 rope overs, 1st rope over compression tells a lot.

Get new plugs run in a barrel then when cooled do a compression test to see what is there. Report values here. I would use a good TCW3 oil at about 20:1. I use 16:1 in the Merc 25ss with Pennzoil XLF and 87 E free fuel, no carbon issues, 7500 revs, race engines love the revs to keep clean and these Merc oldies with full complement crank journal and wrist pin rollers love oil at the high revs.

[zul8tr]

any leads on a steering bar like you mentioned?

I believe the rear bolt spacing on your block is the same as the Mark 20H if so here is a steering bar they are real nice

https://btmco.com/product/1414-mercury-20-h-assembly/

maybe others can verify on spacing.

[cocacola]

I believe the rear bolt spacing on your block is the same as the Mark 20H if so here is a steering bar they are real nice

https://btmco.com/product/1414-mercury-20-h-assembly/

maybe others can verify on spacing.

Love it!
great price too

[cocacola]

I did not get to the things I wanted to this weekend.
Removed and cleaned up prop.
Also removed flywheel to check out ignition plus is seems like rotating that lever to advance timing was stiff.
Cleaned off old lube and put a thin layer of grease in those areas and reassembled MINUS the cover and flywheel.

Comments on what you see please....
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[zul8tr]

What was the condition of the prop shaft that was covered by the prop when you pulled the prop?

If you do get serious and run it that old style long ear prop has to go, but worth a use just to get operational. Many props available for an update for that 1:1 gear case

What is the condition of the crank shaft point contact cam surface?

Any pitting on those points contact surfaces? If none may just need to be properly cleaned, I do it as needed on my Yamato Y80 point ignition. Any looseness on the point lateral rocking about its post pivot support? Check point contact alignment by looking at the surface wear pattern, if not square needs to be adjusted to clean properly.

Since those coils look cooked before pulling the flywheel did you check for good spark?

Not sure about replacement coils or condensers availability, some places to search:

https://johnsoldmercurysite.com/phpBB3/index.php

There is a $15/year fee to get to parts, tech, white papers and other. General and some other areas are free to view but to not comment or ask questions

Parts may be available from:

http://www.aeroliner-boats.com/index.html

Also maybe:

Frank Erion

269-730-1337
email - fderion@msn.com

Also maybe:

Possible John Mcintosh:

http://www.johnsmcintoshvintagemercuryoutboard.com//About.html

Maybe Old Mercs:

https://www.oldmercs.com/Default.asp

Maybe Outboard paradise:

https://stores.outboardparadise.com/

There are others.

NLA parts difficult to get since as they age they transform to Unobtanium ;-)

Good hunting
Pete

[cocacola]

What was the condition of the prop shaft that was covered by the prop when you pulled the prop?

If you do get serious and run it that old style long ear prop has to go, but worth a use just to get operational. Many props available for an update for that 1:1 gear case

What is the condition of the crank shaft point contact cam surface?

Any pitting on those points contact surfaces? If none may just need to be properly cleaned, I do it as needed on my Yamato Y80 point ignition. Any looseness on the point lateral rocking about its post pivot support? Check point contact alignment by looking at the surface wear pattern, if not square needs to be adjusted to clean properly.

Since those coils look cooked before pulling the flywheel did you check for good spark?

Not sure about replacement coils or condensers availability, some places to search:

https://johnsoldmercurysite.com/phpBB3/index.php

There is a $15/year fee to get to parts, tech, white papers and other. General and some other areas are free to view but to not comment or ask questions

Parts may be available from:

http://www.aeroliner-boats.com/index.html

Also maybe:

Frank Erion

269-730-1337
email - fderion@msn.com

Also maybe:

Possible John Mcintosh:

http://www.johnsmcintoshvintagemercuryoutboard.com//About.html

Maybe Old Mercs:

https://www.oldmercs.com/Default.asp

Maybe Outboard paradise:

https://stores.outboardparadise.com/

There are others.

NLA parts difficult to get since as they age they transform to Unobtanium ;-)

Good hunting
Pete

Now that's a lot to chew on......see responses in CAPITALS below.

What was the condition of the prop shaft that was covered by the prop when you pulled the prop?
I WILL TAKE PICTURE. NO LOOSE METAL PIECES.
WHAT HOLDS ON THE SHEAR PIN?
IS IT JUST POUNDED IN?

If you do get serious and run it that old style long ear prop has to go, but worth a use just to get operational. Many props available for an update for that 1:1 gear case
NOT GOING TO CHANGE PROP…THIS IS MOSTLY JUST A COLLECTOR ENGINE FOR ME.E

What is the condition of the crank shaft point contact cam surface?
LOOKS SMOOTH

Any pitting on those points contact surfaces?
NO PITTING. LOOKS SMOOTH

If none may just need to be properly cleaned, I do it as needed on my Yamato Y80 point ignition. Any looseness on the point lateral rocking about its post pivot support?
NO LOOSENESS THAT I CAN TELL
Check point contact alignment by looking at the surface wear pattern, if not square needs to be adjusted to clean properly.

Since those coils look cooked before pulling the flywheel did you check for good spark?
NO I DID NOT, BUT IT DID FIRE ON AT LEASE 1 CYLINDER WHEN I PUT STARTING FLUID IN IT.

[zul8tr]

The shear pin is held in by tightening the prop shaft nut the right amount that puts the shear pin in double shear. If tightening right, not to tight to bend the pin it will stay there. I use a nylock nut and have never lost a pin.

[cocacola]

I removed the lower unit last night.
Not changed oil/grease.
The left hand threaded cone was not tight and loose enough to remove by hand.
Is there a seal or o-ring missing?
Now I see where water pump is.

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[cocacola]

duplicate posting

[cocacola]

another duplicate posting....sorry.

[cocacola]

The cone is the early sleeved design with no roller bearings as in the later design. It has no petroleum lubrication just water. There is no O ring that I know of, when the cone is tightened its solid back provides the closure for the water pump chamber. The condition of the prop shaft reveals corrosion but useable - it probably wasn't greased often. Way back I had one of those Q tower Mercs (20ci power head) with the bushed cone and I would often remove the cone and grease the prop shaft, especially for prolonged storage - helped a lot.

The condition of the drive shaft at the spline is good but at the pilot seal it is poor. The seal relies on a smooth surface to keep the seal lip wear down. If you will use the engine for display no worry but to run it often the seal needs to be replaced and see if the shaft seal surface can be cleaned up?

The gear case design when secured to the tower was such that it trapped water in that pilot seal area after running not good. If the water was not removed and engine sat unused it would promote rust at the pilot seal. After each use I would dump the water out and spray lube that area and never have the rust problem in all the 2 cylinder Quicki Mercs I had and with the 25ss I still use.

Would like to see the condition of the gear case lube when you drain it if oil. If grease that will take a bit of doing - there are ways to aid that process.
I use gear 75w-90 synthetic gear oil.

You are keeping my busy and educated....thanks again.
I will show the lube when I get back to it in a couple days.

I am a gearhead, but am new to this.
I did work on my 115 & 200 Mercs....this one is more fun so far.

[zul8tr]

Very up on these Quicki Merc race engines and their guts. Did a lot of testing, rebuilding and racing of these. Happy to help

[cocacola]

finally got back to things last night...
scrubbed and cleaned lower unit with simple green, scrub pad and steel wool.
Used a scribed to free up any debris in water pick up holes.
Removed impeller.

No oil or grease in lower.
The bottom screw looked like it had some grease on it.
Brass screws....does that sound right.

Are there supposed to be seals or o-rings behind those screws?
There was one behind the larger screw, but it blew out into the yard when I was cleaning....it looked old anyway.

The shaft turns silky smooth, no grinding or rough spots.

[cocacola]

finally got back to things last night...
scrubbed and cleaned lower unit with simple green, scrub pad and steel wool.
Used a scribed to free up any debris in water pick up holes.
Removed impeller.

No oil or grease in lower.
The bottom screw looked like it had some grease on it.
Brass screws....does that sound right.

Are there supposed to be seals or o-rings behind those screws?
There was one behind the larger screw, but it blew out into the yard when I was cleaning....it looked old anyway.

The shaft turns silky smooth, no grinding or rough spots.

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[cocacola]

more pics

my son in law has a nice buffing wheel on his grinder....might polish this thing a little once it's up to standard.

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[DeanFHobart]

If you are going to run the engine much at all, I would suggest getting a new water pump impeller and get a new needle bearing cone…. They are all available new. Use lots or grease installing them…. I would suggest White Lubriplate #105 or equivalent…. Something for marine applications. The prop shaft is probably OK for minor running….. Polished as you mention…. For display I personally would make it a ‘Green Tank and Rim. You would need the front tank bracket and rear water plate.

[zul8tr]

Looks improved. No lube, interesting.

Yes there are flat hard seals behind those 2 plugs (like the red one that blew out) available at Frank Erion or Aeroliner (or some others) in resources above post. Look at the impellor blade root and see if there are any rubber cracks on each side of the blade root, if cracks no good need to replace. These are available from resources noted previous. There is a seal at the prop shaft in back of the water pump cartridge (last pic) as well as a seal in the pilot at the drive shaft (see pic). These are not a 1st time DIY to replace, there is a puller tool for the water pump cartridge (can be made) for that seal (CR5522). Then with that out remove the drive shaft gear and pull drive shaft out with ball bearing and the pilot as a unit to replace the seal in the pilot. Putting water pump cartridge in correctly requires that you index it before removal.

Does the drive shaft have any up-down play there should be some? Any lateral play, should be none. Does the prop shaft have any in-out play, any lateral play, should be very minor if any in both cases?

To check gear lash pull up on drive shaft and slightly small CW and CCW moves of the prop shaft to feel the lash. Should be perceptible, setting is about 0.004".

All seals are needed to run the engine on a boat to prevent water entry. Also if going to run replace the prop shaft nut with a nylock nut (my preference to a lock washer).

Also The outer cone inner bushing does wear out and if excessive wear it would have to be replaced if going to run on boat (available from references). Would also need water pump impellor if bad as noted testing above.

Will you be getting into the carb to clean, etc?

But if just a display engine just clean it up put in gear oil (75W-80 standard good enough, some use 105 grease) reassemble and make it look pretty buffed out etc.

[cocacola]

thanks Guys!!!!!
You keeping me busy again.
I will get back with answers to questions.

I did not feel any looseness or play in the shaft, but will recheck.

[cocacola]

Not spent too much time on this lately.
Ordered fuel pump kit since it looked terrible.
Cleaned carb and reinstalled.
Threw away old fuel lines and replacing soon.
Going to visit my good friend Tom Williams at Old Camp Joy (https://www.oldcampjoy.com/) next week.
Bringing engine for him and son to look at.
Tom has helped me along with friends on this chat in regards to this engine.
Not purchased anything else....maybe saving for the vintage boat plans I bought on eBay years ago.