1965 merc 1000...OR Mark78a Dockbuster {PICS}

Hello I picked up a 1965 merc 1000 today for cheap. The guy says it runs but when at wot he says it seems like there should be more power. Said the reeds might be bad or a crank seal might be bad, could only be one of two problems. I bought it anyway. Reason is in the off season I want to rebuild this motor for replacement of my force 85 hp. Has anyone ran into a wot problem such as this, if so was it one of the two issues I was told? If this motor is not worth the fix I would like to know as my force runs like a champ, I am just looking for more HP to push my 18 footer along. I would guess that a merc 100 would give me more power than the force 85, right? I know yes it has 15 more horses but over all power I am sure the merc is better performance. I have also heard the ol story about the 100 hp model being a 115 model with a 100 hp sticker just to get the higher horse motor on a lower rated boat. That has salesman written all over it! lol Any info you all can give me will be much appreciated.

thanks
cordell

Re: 1965 merc 1000...worth the time?

Re: 1965 merc 1000...worth the time?

Lose of power at WOT could be caused by dirty carbs, weak ignition , lose of compression or any combination of these.

Start with basics, connect a battery and spin it over, test compression and test spark, if both are acceptable then it is a safe bet that the engine is capable of performing with a little TLC into the carbs.

Re: 1965 merc 1000...worth the time?

Re: 1965 merc 1000...worth the time?

You are not gonna believe this! I started looking at this motor a little better and it has a Mark78a cowl, but the transom mount has the serial number #1894090. So is there any picture I could post or any way to find out what motor I really have?

Did I get tricked into a dockbuster? It has the 100hp stickers. lol

help please
cordell

Re: 1965 merc 1000...worth the time?

Re: 1965 merc 1000...worth the time?

Post a picture. The serial numbers say it's a 1965 Mercury 1000. Maybe it's just mixed parts.

Dan

Re: 1965 merc 1000...worth the time?

Re: 1965 merc 1000...worth the time?

OK this thing is driving me crazy! I think it is a dockbuster, then it is a 100 hp merc 1965. Back and forth I go. Here is the motor with the LU off as I have been playing around trying my damnedest to figure this thing out. You cant see from this shot but it has 1 distributor and it moves as the throttle arm moves, when pushing the throttle arm to WOT it opens the butterflies on the 3 carbs. I already know the $5 cylinder is gone NO compression at all! I took the plug out and looked in its hole and the piston looks rough on top sort of melted. If I have a 1000 merc like the serial # says then I will tear down and fully rebuild. If I have the buster I sell now and hope to get mt $60 back. LOL
Did you notice the 2 coils?


Here is the LU the LU seems to have NO shift shaft, though it has this little splined thing that is flush with the top of the LU. It connects to something in the housing that goes on what I would think a place for a shift control. The reason I believe a dockbuster is the lack of shift shaft. Also it seems to want to turn the prop in only one direction, even when rotating the little spine that could be the shift control.



Thanks for all the time and help

cordell

edit searching threads for a 1965 merc 100 this LU looks NOTHING like mine lol

I alos dug a little deeper into the motor. The throttle linkage also hooks to the shift linkage. Could this have a forward gear only????

http://forums.iboats.com/showthread.php?t=238672&highlight=1965+merc+1000

Re: 1965 merc 1000...OR Mark78a Dockbuster {PICS}

Mark 78 were only made in 1958 and 59. The 100hp always had full gear shifts. The splined thingy you found is the shift rod. Rotating it moves a cam in front of the propshaft pushing a rod connected to the clutch dog. ROtating this shaft while the gearcase is removed usually results in an engine that has shift issues.

Post a pic of the cowl wrap please.

Re: 1965 merc 1000...OR Mark78a Dockbuster {PICS}

Yep that is a Merc 1000. I have a 68 model here that needs the typical wiring job on it . I sent you a PM Cordell.

Re: 1965 merc 1000...OR Mark78a Dockbuster {PICS}

I will post a pic tonight....My question then is if it is a shift shaft where does the shift cable hook too? I did follow this little shaft all the way up into the cowl area and found the linkage connects to the throttle linkage...how would one shift into reverse? Or am I being a noob and would know if I had a set of controls....lol Like a Force it has only one handle that controls 2 cables.

thanks
cordell

Re: 1965 merc 1000...OR Mark78a Dockbuster {PICS}

Two major differences in a dockcrasher

Starter drives, notice the 's', since a starter threads the drive into position then reversing rotation for a dockcrasher involves a different method of engaging the drive.

Second, since you have the LU off you should take note of which water pump is installed, here again the dockcrasher uses a special pump with both inlet and outlet 'valves' which will allow the pump to move water either direction of rotation.

You do not have a dockcrasher.

Re: 1965 merc 1000...OR Mark78a Dockbuster {PICS}

Thank god I dont have the crasher! Here are the cowling pics you asked for. I will now proceed to do a total rebuild of this motor. Or that is my plan anyway. I have a good running motor on my boat now I just need more power... Is this actually the same block as the 115....or was that something that had not been invented yet? lol

cordell

Re: 1965 merc 1000...OR Mark78a Dockbuster {PICS}

I think the 115 came out later on, which I believe they are 2 different blocks but I could be wrong.

Re: 1965 merc 1000...OR Mark78a Dockbuster {PICS}

Totally different design between your 90 Cubic Inch 100HP and a 99 C.I. 115hp.....ed

Re: 1965 merc 1000...OR Mark78a Dockbuster {PICS}

How many control cables come out of the remote? Also where they connect to the engine, inside the cowl or outside?