vapor lock?

diggs

Seaman Apprentice
Joined
May 8, 2005
Messages
37
Have a 1996 200hp johnson. Just took it in to a mechanic since i feel i lost a little at the top end (about 5 mph) and after runnig over 3000rpm's for more than 5 minutes it wont start right away. I have turned it right off, let it idle for 5 minute, and have puttered at slow speed for awhile also to help cool it down. Still wont start right back up, it sputters and has very little water pressure low rpms then dies. If i put the neutrl up a little it will start and can lower the neutral after 15 seconds and it is fine. Mechanic called and said it was vapor lock causing this. His fix is to #1 replace the vro pump since he feels older pumps put in too much oil, #2 change gaskets on carbs and clean them as well. Does this seem right, minus a hub repacking the price would be $900.00 , seems high not sure what to do
 

mikeyzx2

Chief Petty Officer
Joined
May 1, 2005
Messages
633
Re: vapor lock?

diggs, you can do the carbs yourself easy. buy a service manual and save yourself some serious dough. I don't buy the fact that he "feels" the older pumps put in too much oil. And you mention cooling it down and very little water pressure. Is the motor running hot? You'll have more issues with a hot motor...
 

diggs

Seaman Apprentice
Joined
May 8, 2005
Messages
37
Re: vapor lock?

I just recently got a manual and was thinking about giving it a try. Do not have a temp guage on the engine but the mechanic said he checked and it was running at the right temp
 

R.Johnson

Rear Admiral
Joined
Sep 24, 2003
Messages
4,446
Re: vapor lock?

You have the first outboard engine with a vapor lock I have ever heard of. Old VRO pumps put out less oil, or were true Variable Ratio Oiling. You would have to have temperature's under the hood to vaporize the fuel in the lines. Engine should come to a sqeaking stop before that. How old is that mechanic?
 

diggs

Seaman Apprentice
Joined
May 8, 2005
Messages
37
Re: vapor lock?

The mechanic is cetified and has been doing it about 15 years. Many people swear by him but im not sure. Any suggestions on what i should do first myself
 

Solittle

Fleet Admiral
Joined
Apr 28, 2002
Messages
7,518
Re: vapor lock?

Testing of your overheat alarm would be first on my list followed by a new water pump. Then follow the procedure in your manual and service the VRO. Might want to check the red search function here at iboats for the VRO service.<br /><br />Oh and nix on the vapor lock - older autos suffer from that.
 
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