Got a question for the knowledgeable. According to the plate on a motor I just picked up last night it is a Mercury Comet KF-3 3.6 hp with a serial number of 359749. But according to http://www.oldmercs.com/models.html A KF-3 is a 3.5 horse and that serial number doesn't match. I just want to know so I can get the right parts. The motor has 130lbs compression dry. Of course it has no spark, but it seems none of these motors I pick up do. I think it will be a good little runner.
Last edited by freddyray21 : August 14th, 2007 at 11:06 AM.
Reason: alter topic to fit new question
A KF-3 is a 49 Comet rated at 3.5 hp, so there may not be an official serial number record to compare it to. Pull the flywheel, clean the points, inspect the coils, wires, condensors and connections. I bet you get spark back unless the coils are toast and they may be. If they're cracked, delaminated you'll have to replace them. Also check the LU grease level, Lubriplate 105, and be prepared to shut it down on the first run in the barrel/tub if the water pump/impeller aren't working. Good little motors...I'm fond of the even earlier 1 cyl. Merc's and Wizards with the Buck Rogers look.
pulled the flwheel and cleaned the points and I have spark. Does anyone know what the gap is. I am assuming .020? It started on the first pull though it will need a carb float and impeller. I have them on order. Also it seems as if there is a lower cowling missing and the front of the carb has two screw holes. I am guessing the choke would be there.
thanks. I have ordered an impellar for it, but am curious as the shaft does not have the tell tale round spot in it for the impeller. I am assuming it is in the lower unit at the top. I don't have a manual so would appreciate any instructions on how to do this one. I have done several in the past but all Evinrudes or Mercruisers.
Okay so I took mine apart and it doesn't look like the picture above. I pull the pin off of the cone, unscrewed the cone. pulled the prop off and mine has the water pump cover that screws into the housing (left hand threads found out the hard way. jb weld in order) then the impellar. The thing is I cannot see how it gets water into the impeller. Unless it is through the little holes pictured. the little holes look like they fit a spanner wrench though.
That picture looks like a quicky lower unit from the water pump cartridge. if it is and the left hand treads aiso sound like a quicky, you have a rare bird indeed the quicky were built for the KG4H and KG7H engines and not for that powerhead can you send a side view of the unit and another of the whole engine please
Here are pics of the motor. It is hard to say what has been done to the motor over the years. I am only going off the serial number and information off the cowl to verify what the motor is. I do know it has good compression and after cleaning the points it started on the first pull. I have ordered parts, but now wonder if they are the right ones.
the picture laddies sent doesn't look like yours, don't see a water intake in front of your prop. the drawing link i sent looks similiar, and shows the impeller inside the leg. how it all comes apart is a different story
the link you sent seems to indicate it is in the leg, but in any event I don't have all the parts in the pic you sent either and no room to put them if someone had left them out. Figures I would have the oddball one.
Thats a early unit for the KF 3, I ad to dig out a 1955 parts and service manual to get this picture, the assembly is done just like the Quicky lower unit so you don't need to pull the w/pump cartridge, the imp. goes in it and is covered by the nut,
Laddies is right. Mercury used essentially the same design on all their direct-drive motors, locating the impeller on the propshaft.
If you should ever need to remove the waterpump cartridge - it pulls out, it is not threaded. Those two holes are for a puller. I find it easier to just pull out the propshaft, which brings the waterpump cartridge with it...
Mercury Comet KF 3 impeller questions
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