Trying to test outbard

[snookhooked]

I have a 1973 mercury outboard it a 650 thunderbolt. I bought this motor what I thought was going to be parts for my 650 mercury outboard which is guessing is betweem 73 to 75 year. anyway. after getting this and finding out its a thunerbolt there is some difference between them but I really think this motor will run so now Im working on it. the thunderbot serial is 3403408 cant find any infor on it but what I would like to do try and start it and go from there but I dont have spark. since the person back out on the merc controller that was to be with the deal and I cant stretch the one on my boat to plug in but how can I get it to fire without the control being plugged in? I dont want to ge crossing something and messing up parts that already are hard to find or way out there in price. I just rebuilt the carbs and starter but now I need to get it to spark to get it up and hope atleast it will run. Im new at this so I hope that I can find the reply for this question. Thanks Steve

 

[jimg984]

Re: Trying to test outbard

80hp 71 or72

 

[snookhooked]

Re: Trying to test outbard

1973 65 hp

 

[snookhooked]

Re: Trying to test outbard

What Im simply trying to do is rather than swaping engines just to use the merc plug, Im trying to get the motor to fire and run where I can find out if it worth doing a swap. my other motor leak where the upper connects with the lower unit and it starts up fine and runs maybe close to half throttle then kills if you try to go to full throttle. carbs have been rebuilt. I cant get the other motor close enough to plug it in. I thought they were going to be the same but Thunderbolt are alittle diferent and I was told that it is a better motor than the normal 650 mercury. I dont have a clue to whats better but all I want right now is a motor that is working and can be used. I am going to try and do my first rebuild or atleast replace all the gaskets on one of the motors and then do the other once I am done.

 

[jimg984]

Re: Trying to test outbard

http://www.eastcoastmarineservice.com/models.html

 

[jimg984]

Re: Trying to test outbard

this is what i looked

http://www.eastcoastmarineservice.com/197072Merc800.htm

 

[snookhooked]

Re: Trying to test outbard

Thanks but I been there. it doesnt help out. I may just have to go through the pain in the butt of removing one motor and put the otherone on there just so I can use the merc plug. it may have something to do with the safety netrual swith on the control to allow it to have spark. I just hate moving. this motors are far from being light, lol

 

[jimg984]

Re: Trying to test outbard

if your engine has a switch box on the motor the white wire would be the ing. which you could feed a hot wire then heavy hot wire to starter and a heavy ground wire then would jumper the solenoid from hot side to small connector with gas should fire up you probably know all this ,, but i would tho throw it out goood luck i'm in the middle of an engine swap and is quite a bit of work

 

[Chris1956]

Re: Trying to test outbard

Snook, If that motor has a distributor, it is a battery driven CDI type. Remove the wrap cowling. Connect the +12VDC pole on the battery to the starter solenoid(large cable that runs to quick disconnect plug), and ground the -12VDC pole to the engine case, using jumper cables. Now connect a small jumper from the +12V jumper cable to the red and white wires on the switchbox(non-distributor side).

Hook up the flusher and fuel, set the manual choke, now connect a jumper wire from the +12VDC cable to the small yellow wire on the starter solenoid. The starter should spin and the motor should have spark, and may even start. Disconnect the jumper to the white wire on the switchbox to stop the motor. Do not disconnect any other wires, or you will blow the rectifier.

 

[snookhooked]

Re: Trying to test outbard

Thanks guys. I will try this and repost what happens. since the other motor leaks between the top and the lower, Im putting hope maybe this one wont and runs good. Im taking the Thunderbolt is a better version on the 650 motor but not for sure. even though the other one runs, it has its problems that in time I would like to fix but I think replacing all the gaskets will straighten it out but I want to see what this one does as well for one of them will be my main motor. Thanks again and I will repost what happens

 

[snookhooked]

Re: Trying to test outbard

I have another question about my other 650 mercury. its between 73 to 76. the first three digits start with 381. right under the cover plate/exaust plate where the top of the motor connects with the lower unit. it dribbles there and get worst as you horse up the power. I asked a local marine repair about this and they acted as if it was no big deal but its not normal to me. I looked up the motor and didnt see any gasket for it but it has red stuff that i am sure is rvt sealer. until I can get a manual, I wouldnt dream of pulling it apart to fix it and thats my palns in the near future. maybe you can tell me more about it? and I also forgot to ask this on that motor. it starts fine and runs about maybe 10 to 15 mph but when I move it to full throttle it stalls. I have comlletely rebuilt the carbs and have tried adjusting it but no better. I was told it could be leaking around some gasket allowing air in but maybe you can send some thoughts ny way to get this problem solved as well. I believe both motors are good and it seems it doesnt take alot to get them back running. hopefully I can get one of them up for my boat by the begining of this comming year? thanks for all your help. it has helped me out a lot for being a beginner in having my first boat. its spark my interst in maybe going to school for outboards.

 

[Chris1956]

Re: Trying to test outbard

if I understood you, you are talking about the exhaust extension to powerhead joint. I would think there would be a gasket there. The water pump pushes water up the watertube into that fitting. That is why it leaks. Silicone may or may not fix it, since it is under pressure.

As for your high speed stall, pump the fuel primer bulb as you accelerate. if that fixes it, rebuild the fuel pump.

 

[snookhooked]

Re: Trying to test outbard

Thanks chris. I will try that. Im not sure on the leak. when I pulled up a blown picture of motor couldnt find a gasket there but that doesnt say ther isnt. that motor is the one I am going to tear down and replace all the seals but good news your help is working on other motor. it has spark and ran for a few seconds. since it has shown that, Im going to do the swap this weekend. the carbs were rebuilt on the other motor so Im going to switch them and the distributor cap and wires as well. the motor ran very quiet and smooth even though the cap on it a part it was broke and super glued back on but what I just needed to know was that it would run. I bought this engine with a guess it would run or be used for parts but it seems to sound and run better so that a plus. I did what you said and the spark was great and it started right up. the other that came with the boat had problems and having this one on the boat will allow me to test my small motor skills and get a book and start a rebuild process. maybe I will have two motors for this boat soon. these motors are 34 years old and parts are becomming hard to find. Mercury likes to change up and discontinue parts which makes it harder. anyway Chris you have helped a lot and Thanks very much....... its a 1974 Range 14.5 ft little boat but Im going to restore it. its my first boat. this is my first outboard to work on so I may be on here a lot asking questions. Thanks again.

 

[snookhooked]

Re: Trying to test outbard

I just thought about this after posting reply. I replaced the whole gas line and bulb to the tank after I had the problem and didnt get back to test. it was weak and old that the rubber inside was comming through the line and into a inline filter I put on it. that makes a lot of sense. since Im changing motors I will keep in mind that I will rebuild pump on it too. doesnt hurt since Im going to be doing all that work to it anyway. Thanks again. Steve

 

[snookhooked]

Re: Trying to test outbard

ok, once again I have a questions. 1. I put the rebuilt carbs from my other 650 merc on this 650 Thunderbolt. it starts up great and runs fine but it like to high idle ok, then I would do the normal thing and thats to adjust carbs. still doesnt really idle down to where I feel it should but thats a matter of opinion. 2. now the strange one to me. the rule of thumb is adjust the carb idle screw to where its closed and back up from there to 1 1/8 for a starting point and fine tune from there but whats wierd on this motor not like the other which this would work, when you start to close the needle down the idle start to climb higher and higher. so I backed the needle out and tighten down to just where it starts to have spring tension and it starts to idle a little high but works. this seems backwards but is it or am I wrong? Thanks

 

[Chris1956]

Re: Trying to test outbard

That sounds about right for that motor. The overall idle speed is controlled by an idle stop screw. Turn it out and te idle will decrease. The adjustments on the carbs are mixture screws. Turn them out to richen. Start at 1-1/2 turns out from lightly seated. Run the motor in the lake, and adjust in gear at idle if possible. Adjust for smoothest runing. Now try to accelerate. If motor stumbles, open idle mixture on top carb 1/8 turn and retry. Repeat with lower carb. Eventually you will find richest setting that allows reasonable idle, and good acceleration.

 

[snookhooked]

Re: Trying to test outbard

Hi Chris. thats sounds right now are reading what you said. I was thinking that it was backwards to me. I got another question on these mortors. both motor seem to have problems in reverse. they grind. now is this something or a normal problem with Mercs? two motor with same problems. when I heard it, I was dang another one having problems in reverse. now the other motor will go in and I havent tride to push it any further, I just heard it and put it back in netrual. just curious. Thanks Steve

 

[snookhooked]

Re: Trying to test outbard

I should be more detailed about it. it grinds when motor is running but if I put in reverse when its not running, it will click but forward has no problem at all

 

[Chris1956]

Re: Trying to test outbard

Perhaps they are out of adjustment. Put the motor in neutral, and remove the nut that holds the shift cable. Now remove the shift cable, and see if you can adjust the barrel nut so it won't move the shift arm, when you reinstrall it.

 

[snookhooked]

Re: Trying to test outboard

Re: Trying to test outboard

I have a question about the gas use. Since I have started to use this mercury 650 Thundebolt, I noticed that it is extremely bad on gas. I ran for maybe ten minutes but then ran mostly at idle spped for a test run. I have a six gallon gas container after running for maybe 30 minutes I burnt almost a half of a tank. to me that is way too much fuel use. is there anything I can do to improve that? it 2 cycle motor. I know they are not known for good gas milage but I think this is way too much consumption for what I would consider very little time in use could you give me some pointers or where I need to improve it to a normal rate of use?