1961 Merc 500

[dg22]

I'm having difficulties getting my 1961 Merc 500 to start. The motor has 120 compression on each cylinder and has spark on each plug. When I try to start it with the choke on, it back-fires really load.

Stuff I did to the motor:

I installed a new fuel pump diaphram, cleaned the carbs, the mag I removed and put back on; aligned the mark on flywheel with the line on the top wheel of the mag and ran the spark plug wires to each cyclinder in the sequence as indicated on the mag (assuming that 1 is the top piston and 4 is the bottom).

I also put a new water jacket gasket which leads me to another question. I don't have my lower unit yet so I'm running a garden hose to the water-tube. When I run the hose, water is leaking out the water jacket...a little surprised because I have all the bolts snug. I tightened them some more and it still leaks.

Any suggestions/ideas would be greatly appreciated.

Dave

[Mike 21CE]

Hi Dave, I think the mark on the top of mag wheel is 40 BTC, if you take the thin plate off and look at the gear carefully there is an arrow which is TDC mark it on the top of the plate . Take out # 1 Plug ( the top) and make sure the piston is at TDC ( put something in the hole and rock the engine by Hand to check). Did you use two gaskets on each side of the plate for the water jacket? Mike

[dg22]

Hey Mike, thanks for the feedback. This is probably my problem. I think I'll get Dave Scott to set the timing on this. I don't have a timing gauge to set it at the TDC position.

Regarding the water jacket gasket, I only installed one gasket between the motor and the water jacket. Maybe I'm missing a part. From what you described it sounds like there is a plate that goes between the block and water jacket. The guy I bought the gaskets from said one is an extra....this explains the extra gasket. I guess I'll need to find a plate for the water jacket....if I here you right?

Thanks,
Dave

[crankbearing]

covers

Dave,

There is only one gasket on the water jacket, I think the spare gasket probably has a blip around #1 plug hole, that is for the newer engine with a temp sensor. I think mike is referring to exhaust cover, there should be a gasket against the block then a stainless plate then another gasket then the cover..

The TDC arrow is your problem.. Take the pulley cover off, Rotate engine clockwise to TDC on #1 piston using a screw driver make sure and rock it over to make sure you are at TDC.. I would use a dial indicator to be sure. Then look at the pulley and make sure the arrow is pointed at the center of the top bearing carrier bolt. or that the arrow and the mark on the flywheel line up..

pretty much what mike said.


Regards,

[dg22]

Thanks Dave...I might just wait and arrange to have you set it when I pick up the lower unit. I'll sort out the water jacket problem. The person before had used caulking instead of a gasket and it was quite a mess to clean-up so possibly I didn't get the surface 100% flat.

Dave, right now the water-tube sticks out a 1/4" at the bottom of the tower. Is this enough for when we install the lower unit? Also, do you have an extra throttle bracket for hooking up throttle cable to this motor?

DG

[ricochet112]

Be careful when running an engine with a garden hose hooked directly up to the water intake pipe. The water must have minimal pressure, it will scavenge water back into the cylinders if the water pressure is excessive.

I ran into this after rebuilding a V6 merc with a jet pump, no way to break it in and set timing on dry land, I hooked water directly to the intake pipe, (jet pump removed) and was getting water on the plugs, starting hard and idling poorly, reduced the water flow to barely anything, and the problem went away. We have 75psi at our city water supply, the impellers put out around 15psi max.

Mike

[crankbearing]

Swap Meet

Hey Dave,

I am sure I have what you need.. you should just bring the motor to the swap meet and I will bring it home with me and get it all 100% for you..

Regards,

[dg22]

Hey Dave, that would be great...I'll see you there.

DG

[Mike 21CE]

Dave I was thinking the side plate for the Exhaust. Mike

[quicksilver96]

Merc 500

Hey Dave,

I am sure I have what you need.. you should just bring the motor to the swap meet and I will bring it home with me and get it all 100% for you..

Regards,

Hi Dave, Need to know what to set max timing on a Merc 500 D Mod engine. I am using Bayer Exhaust and KC Carbs with .065 jets. Any help will be appreciated.. Using Merc Lightning Energizing Ignition and have had many different oponions on this... Bob N-96

[crankbearing]

kc and timing

Hey Bob,

glad you got it together.. You;ll have to come up and play with us some in the north..

OK, I am running .067 in my mod with KA carbs.. I would go up a couple jet sizes to start with until you get it dialed in.. you do not want to damage those new wiseco's the first time you run it.

Timing, I would start at .300 and go up from there. remember that more is not always better. Those wiseco's if you bored to my specs will take a lot of pounding but not a lot of high timing on the domes. remember this - play with spark plug types..

Regards,

[quicksilver96]

Timing D Mod

Hey Bob,

glad you got it together.. You;ll have to come up and play with us some in the north..

OK, I am running .067 in my mod with KA carbs.. I would go up a couple jet sizes to start with until you get it dialed in.. you do not want to damage those new wiseco's the first time you run it.

Timing, I would start at .300 and go up from there. remember that more is not always better. Those wiseco's if you bored to my specs will take a lot of pounding but not a lot of high timing on the domes. remember this - play with spark plug types..

Regards,

Thanks for the information, shooting for Franklyn, PA for the first time to try this engine. ....Bob

[dg22]

Water Jacket

Fixed the water jacket. I just needed to clean up the surface a bit more on the water jacket. Last time I say 'good enough'. Also installed new bolts. I tested it with the hose and she is good now.

See you guys at the swap meet.

DG