Mercury Mark 6 Comet twin 5.9 hp questions

DamianJP · Feb 2, 2011

Hey guys

Iv'e found a older merc I can get for about $150 and it was a Mark 6 Comet twin 5.9 HP.
My only concern is getting parts. Serial number is 951315 and I think its a 1955 but not sure, If anyone can help me with more info that would rock.

Were would I get parts and prices for parts for this motor?

Thanks,
DamianJP

carholme · Feb 2, 2011

Re: Mercury Mark 6 Comet twin 5.9 hp questions

Damian;

Yes, 1955, comes up as a Mercury Comet Silent 6:

http://www.discount-marine-parts.com/ob_mercury_2.html

Have no idea about parts but if you enter Mercury Comet Silent 6 in the search engine at the top, it will bring up three threads in Iboats. You might try contacting one of those guys to see where they got their parts.

There are a few videos on Google, if you type the same into their search engine.

Gerry

merc850 · Feb 2, 2011

Re: Mercury Mark 6 Comet twin 5.9 hp questions

Try these guys I have restored 2 motors with their parts http://store.eastcoastmarineservice.com/category_s/121.htm

DamianJP · Feb 2, 2011

Re: Mercury Mark 6 Comet twin 5.9 hp questions

Cool thanks for the feedback

Carholme for the check on the year!!

Mercy850 for the parts source !!

At $150 I'll go ahead a try it out. I don't like to throw money away but I'll take the chance on this. Nice piece of history by merc,and if something pops it's head up were it's too much to fix it , it will still look cool in my small shop.

My plan though is to grab a manual and do the carb,waterpump,points,lower lube and actually use it. Seems like the site you gave me Merc850, the manual is most expensive thing at $75. So figure $75 for manual and another $50 or so for other parts.

Thanks again,
DamianJP

JasonAych · Feb 4, 2011

Re: Mercury Mark 6 Comet twin 5.9 hp questions

Short answer: They are probably NOT suited for someone who intends to use it every day and not willing or not able to wrench on them. Unless of course you have disposable income and can find someone willing to do it and pay them.

Details:
Unless they were ever replaced most likely the coils will be cracked and bad. Phelon replacement coils are about $45 - $65 per coil. Special merc tool needed to get the flywheel nut off.

Pay attention to the LU. They notoriously take in water and crack in freezing weather among other issues water would cause. Look for cracks or separation of the metal of the casing in front of the prop. The Driveshafts and/or dry and hardened seals are usually the cause of the issue. They had a chrome plating that is usually worn through at the seals and bad pitting making them hard to ever reseal again. This happens more often with salt water motors. There is a fix involving having a ring of SS welded around the seal area and having it ground down on a lathe and polished. Obviously an expensive fix because it involves machining. If the casing is good, you can avoid this job by replacing the LU grease (lubriplate 105) often and just before freezing weather. Again, not good for an everyday motor.

Water pump is pretty typical to replace. Just be sure to loosen the clamp that holds the shift cable when pulling the LU down. The impellor can be bought just about anywhere that sells Sierra. NAPA being one of them. The part number is 18-3012.

When all said and done they are awesome little fishing motors and as usual with most of the Mercs from that era are under rated HP wise. They are lightweight and sleek. They have the potential to run nice when tuned right

Many parts can be had at the fore mentioned website.

Hope that helps!

DamianJP · Feb 4, 2011

Re: Mercury Mark 6 Comet twin 5.9 hp questions

Thanks JasonAych

Thanks for the info and 'trouble' spots to look for. Looks like an all freshwater motor so mabey im in luck with that chrome plate/pitting. I'll remeber if I do use her here and there to be easy. It's will be very rewarding to breath some life into her and take it out on my small Jon boat and land a few tarpon.

That tool is %100 needed to get fly wheel off? Seems I have a hex nut under the piece that the special tool fits on that would fit a open end wrench.

Gonna cost me some more money with special tool/manual and then parts but.... when do you get a chance to rock a old merc out and get enjoyment out of a nice piece of machinery? He has another Mark 5 there for about $375 that has been babied from the looks of the outside and inside. I'm feeling Old merc fever and might have to snatch it up .

Old outboards in general, I like to get em' do some diggin' on google and find out the history behind that motor and it's companies whole history. Very fun.

Thanks again ,
DamianJP

merc850 · Feb 4, 2011

Re: Mercury Mark 6 Comet twin 5.9 hp questions

To remove that starter nut you can use a pipe wrench and tap on it with a mallet, get someone to hold the flywheel at the same time. To pull the flywheel you'll need a puller with 3 arms or slots(a harmonic balancer type) and three bolts to thread into the flywheel holes. Thread bolts down about an inch and check that they are even when puller is tightened, tighten puller screw and tap on it then tighten again and tap. Sometimes on stubborn ones you can leave it for awhile under tension then repeat tapping/tightening.

steelespike · Feb 4, 2011

Re: Mercury Mark 6 Comet twin 5.9 hp questions

My very limited experience with Mercs is they often need special tools to work on
While well engineered but imo they are just a little off the main line design wise.
The 5,5.5 and 6 hp Evinrude/Johnson motors are simple and rugged.I used to do a lot with pliers,screwdriver and a cresent werench. Routine parts
are readily available back to the early 50's some right here at Iboats.More obscure new and used parts are available from well established BRP dealers and many venders across the country.

JasonAych · Feb 4, 2011

Re: Mercury Mark 6 Comet twin 5.9 hp questions

I am a fan of all classic and antique outboards. I have some examples of quite a few brands. To stick with the topic, I have a Mark 6a and Mark 5 (almost done). I really like both and can't wait to get them on the water when the weather breaks. I like wrenching on them and the satisfaction of running them when I am done. I have heard of using pipe wrenches and adjustable wrenches on the Merc starter gear/flywheel nuts but, as a personal preference wouldn't do that unless I really had to. The issue I see here is when it comes time to retorque with a torque wrench.

DamianJP · Feb 4, 2011

Re: Mercury Mark 6 Comet twin 5.9 hp questions

She's got life. Did nothing to see what I'm working with. Had to make a make shift gas line to tie into the one someone before me cut!!

But it is what it is. Only fired it twice until I sort the other stuff out, gonna take it back to Florida and work on it SLOW and do a good job. Tool is $33 but I think your right, need it to use the torque wrench.

So
Tool $33
Manual $75
Various parts $100+ mabey
The look on someone's face when I come cruisin up my small canal to my tarpon spot in style. (Priceless)

Is this the manual i'm after?
http://store.eastcoastmarineservice.com/product_p/90-25500.htm

Thank you Carholme , Merc850 , JasonAych , SteeleSpike for all the info and help. If you think of anything else lemme know. Or if I run into trouble, I'll ask for some help.

Thanks,
DamianJP

bktheking · Feb 4, 2011

Re: Mercury Mark 6 Comet twin 5.9 hp questions

Tool- pipe wrench with 2 small blocks of wood and a strap wrench, I've never torqued one of those starter nuts back on , just tighten as tight by arm strength and go.

Link to parts breakdown-

http://pub9.bravenet.com/photocente...m=49338#bn-photocenter-1-1-737212788/49522/1/

john's old merc site- super awesome resource- Dave B is great for lending a hand, if you get stuck he will even give you his phone number to solve the issues.

JasonAych · Feb 5, 2011