power problems

[temdkm]

I have a 1986 mariner 200hp ob. It is on a 1986 Stratos 189 v bass boat. When i unload the boat at the lake, the motor will run just great. When stopped to fish for about 1 hour or so then start the motor back up it starts just fine and idels great. When the motor is put in gear and start to take off I can only get about 2000rpm and boat will not nose over. I have had the motor checked by two different mechcanics. The carbs have been cleaned and adjusted. The stator has been changed. and I have tried numerous pitches of props. Still have the same issue as stated above. Can anyone help with this problem. Thanks

 

[JUSTINTIME]

Re: power problems

fuel pump?
try pumping the build while underway
other than that vent lines and fuel lines

the mechanics never did a test run?

 

[JasonJ]

Re: power problems

Does it eventually give you full rpms, or does it just stay at 2000 rpms the rest of the time at WOT? I have had a few motors do what you describe, I usually had just let them idle for a few seconds before opening them up. Don't know if the carbs had cooked the gas out of the bowls or what. What you could try next time is to prime the bulb. If it firms up after a couple of squeezes then there is plenty of fuel in the carbs. If it takes a bunch of sqeezes then it could be losing fuel. Do you trim the motor up when you stop? That could empty the bowls too. Good luck...

 

[temdkm]

Re: power problems

fuel pump?
try pumping the build while underway
other than that vent lines and fuel lines

the mechanics never did a test run?

Thanks for the response. I'll check these out the next time i go to the lake. The mechanics never did take it to the lake for a test run.

 

[temdkm]

Re: power problems

Does it eventually give you full rpms, or does it just stay at 2000 rpms the rest of the time at WOT? I have had a few motors do what you describe, I usually had just let them idle for a few seconds before opening them up. Don't know if the carbs had cooked the gas out of the bowls or what. What you could try next time is to prime the bulb. If it firms up after a couple of squeezes then there is plenty of fuel in the carbs. If it takes a bunch of sqeezes then it could be losing fuel. Do you trim the motor up when you stop? That could empty the bowls too. Good luck...

Thanks for your quick response. It does give me full rpm usally after about 20 to 30 minutes of ideling around the lake. I do not trim the motor up when i stop. If i try ideling around with rpm about 900 to 1000 rpm I have to watch the water temp closely, because it will rise. I will check the fuel pressure issue the next time i go to the lake.

 

[JUSTINTIME]

Re: power problems

if the mechanics never did a test run, they never tuned it correctly, unless they had a test tank