1993 omc 5.0 rebuild from block help

dadtodc

Petty Officer 2nd Class
Joined
May 29, 2011
Messages
117
Haha, not starting in wot on purpose. Sorry I wrote the post in a defeated rant. Haha so I am trying to start but throttle in neutral and it starts in wot. Cable is connected. Motor isn't new it's older, but I rebuilt it. So it's first start.
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,583
Haha, not starting in wot on purpose. Sorry I wrote the post in a defeated rant. Haha so I am trying to start but throttle in neutral and it starts in wot. Cable is connected. Motor isn't new it's older, but I rebuilt it. So it's first start.

Suggest removing the cable to see if it will idle down
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,468
Suggest removing the cable to see if it will idle down

Ayuh,..... After the 1st time, go back 'n see what ya hooked up wrong, or unhook it,...

A remote start switch can be made outa a momentary push button switch, 'n a couple lengths of wire,...
A plain ole toggle switch can hot wire the coil's (+) terminal, 'n ya don't even need the key,....

Work at the motor, not the helm,....
 

dadtodc

Petty Officer 2nd Class
Joined
May 29, 2011
Messages
117
Well I was at the lake. So options were limited. Should have tested at home but it is what it is. My question is what do you think is causing the wot startup? Also what do you think the knock might be now
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,468
My question is what do you think is causing the wot startup? Also what do you think the knock might be now

Ayuh,..... Look at the Carb,.... Is the throttle at Wot,..?? Disconnect the throttle linkage,..... Look at what the carb's doin',.....

As for the knockin',.... Donno,.... Square one in knock diagnosis,.....
At idle, remove each spark plug wire one at a time, 'n see if the knock lessens, or goes away,...
That's the problem cylinder,...
 

dadtodc

Petty Officer 2nd Class
Joined
May 29, 2011
Messages
117
Ayuh,..... Look at the Carb,.... Is the throttle at Wot,..?? Disconnect the throttle linkage,..... Look at what the carb's doin',.....

As for the knockin',.... Donno,.... Square one in knock diagnosis,.....
At idle, remove each spark plug wire one at a time, 'n see if the knock lessens, or goes away,...
That's the problem cylinder,...

Awesome trouble shooting advice on the knock Bondo. I will do that as soon as I get home. As far as the carb goes on start and in neutral throat is closed. I'll video. We are camping and I got so mad I took the darn thing back home so I didn't stress about it the rest of our trip. Otherwise I would have stayed in the boat and tore it apart. Haha I will try the plug idea.
 

dadtodc

Petty Officer 2nd Class
Joined
May 29, 2011
Messages
117
Well I pulled the motor back out tonight. I Pulled the boat into the yard and put on muffs. I couldnt get started. Acted like there was not enough fuel. I noticed that the throttle linkage was connected and in WOT. I took it loose and tried to manually throttle while my son turned over. Carb kept coughing. At one point it caught on fire. I couldnt keep it going without the coughing. I checked oil dipstick and oil is still clean. I pulled the valve cover and oil is white. So I yanked it back out and decided to tear it all down again and find the knock. I feel like just throwing in the towel,but I refuse to lose. Any ideas the white oil? The oil in the motor was clean. May head gasket?
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,583
White oil (milk) is caused by water getting mixed with the oil. You either have a gasket leaking or a crack which was not found.

The coughing of the engine is caused by timing not set correctly or plug wires not in the right order
 

dadtodc

Petty Officer 2nd Class
Joined
May 29, 2011
Messages
117
Well back to the drawing board. Motor I bought has a cracked cylinder. I pulled the heads and water was in them like before. Out of 8 cylinders 6 were scored beyond boring, and one was cracked. I trusted someone that has a great local reputation. Bought a Marine motor from him that he said runs great. Now I am out money and anything resembling a working motor. I am ready to scream. I have a good block, but I just dont have the money to buy new pistons. I can get rings, and bearings but can I use my old pistons?
 

ruggles

Petty Officer 2nd Class
Joined
Jul 30, 2008
Messages
110
Man I'd be pissed! Take it back to him and tear him a new one!
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,583
Well back to the drawing board. Motor I bought has a cracked cylinder. I pulled the heads and water was in them like before. Out of 8 cylinders 6 were scored beyond boring, and one was cracked. I trusted someone that has a great local reputation. Bought a Marine motor from him that he said runs great. Now I am out money and anything resembling a working motor. I am ready to scream. I have a good block, but I just dont have the money to buy new pistons. I can get rings, and bearings but can I use my old pistons?

Sorry to hear about your trouble. Have you asked if he will take it back?

You can hone the cylinders and use the old pistons, only if the cylinders are no more then .010 over size. The top grove will need to be removed and the cylinders honed. You can buy new bearings only if the crank shaft has no scores and you have it polished. Same issue with the cam and cam bearings. All of this I would not recommend, but it still requires the items to be looked at by a machine shop before you start.
 

dadtodc

Petty Officer 2nd Class
Joined
May 29, 2011
Messages
117
Yes I called him and asked him about taking it back or at least giving me back some money. He already spent the money and doesnt have it to give. Its an older fella and I just dont feel good about beating his tail. Although I really want to. I still have the first block that I bought for 170. I took it to a machinist and had him check it out. He says it needs to be bored over .30. So now I have to find new pistons, rings, main bearings, rod bearings, cam bearings, front and rear seals, and what ever else I have to have. This should have been done in the first place. I was on my way to the machine shop with the block and this fella called me to tell me about a complete motor that runs like a champ. Only reason it isnt in a boat is because the boat had a leak and needed to be repaired. They took the motor out to repair floor and never put it back in. I trusted the fella but that not gonna happen anymore. So now I am out 700 for the motor I bought, 200 for the new oil, filter, power steering fluid, and gasket set. 300 for labor to bore the new block and install cam bearing. 250 for pistons and rings if I go cheap, 200 more for oil and gasket set again. So all together I am in this for 1650. Maybe a little more by the time I am done. All because I was to lazy to climb down and see If i could see the water drain plug. Also because instead of just rebuilding a block I tried to cut a corner and buy a motor to drop in that had been sitting. I could have bought a rebuilt motor from a machine shop for what I have in this now. So a good lesson is to never trust anyone that is selling anything without tearing it apart or low balling the price. Also never think that it doesnt get cold enough in South Carolina to crack a block. This is an expensive lesson to learn. When I get the pics all lined up and in order I will post a video and a how to on the problem. maybe someone will stumble upon this thread while thinking of how to rebuild an engine or wondering how to winterize. I will post to this thread when I get it done.
 
Top