50 hp force starts great when first in the water and wont start again.

gsl10

Recruit
Joined
Oct 15, 2012
Messages
2
Hope someone can help. I have a 1988 50hp force motor on a Blue Fin i just completely rebuilt. the motor starts and runs great out of the water and when i first put it in the water. i run to where im going to fish and then when i go to start it again it just turns over and wont start. I use the trolling motor to get back to dock, get it out of the water trailer it home and it starts perfect. i've had the compression check and is good, new plugs, new impellor, new gaskets for the carb., ive cleaned the carb ( it ran real rough before i cleaned it). new gas with ethanol treatment.

Anyone have any idea why it wont start until its on the trailer and back home. does this sound like the float may be sticking?

Im thinking the boats afraid of the water like my water dog is.

I would appreciate any ideas. im hoping to be able to repower the boat over the winter. but if the funds arent there i would like to be able to figure this out.

thanks in advance.
 

Jiggz

Captain
Joined
Oct 23, 2009
Messages
3,909
Re: 50 hp force starts great when first in the water and wont start again.

Unfortunately, you were not able to do some troubleshooting when the problem was present like checking for fuel in the carbs, sparks from the plugs, removing the cowl during starting to see if the engine will start in the water with the cowl off. First thing you need to do is get a big deep bucket or trash can and submerge the LU like it is in the lake or body of water.

Try starting and stopping and starting until you can duplicate the problem. When the problem arises, remove the cowl and start again. If the problem persists, check for sparks using spark testers. If there is spark but the problem persists, check for fuel in the carbs either by choking while starting or by using the priming bulb if it gets hard at all. If there is fuel in the carbs, manually open the throttle valve while starting. If the engine starts, it is a clogged idle port.

symptoms and related problems:
The problem goes away with the cowl off - most likely exhaust leak from exhaust plates or bottom seal
The engine has no spark - a loose wire either in the trigger or stator is touching ground or looses connection
The carbs has not fuel - faulty fuel pump or leaky fuel hoses and connections
The carb has fuel but nothing into the engine - carb idle ports clogged
 

gsl10

Recruit
Joined
Oct 15, 2012
Messages
2
Re: 50 hp force starts great when first in the water and wont start again.

Thanks for the help i will try.

Unfortunately, you were not able to do some troubleshooting when the problem was present like checking for fuel in the carbs, sparks from the plugs, removing the cowl during starting to see if the engine will start in the water with the cowl off. First thing you need to do is get a big deep bucket or trash can and submerge the LU like it is in the lake or body of water.

Try starting and stopping and starting until you can duplicate the problem. When the problem arises, remove the cowl and start again. If the problem persists, check for sparks using spark testers. If there is spark but the problem persists, check for fuel in the carbs either by choking while starting or by using the priming bulb if it gets hard at all. If there is fuel in the carbs, manually open the throttle valve while starting. If the engine starts, it is a clogged idle port.

symptoms and related problems:
The problem goes away with the cowl off - most likely exhaust leak from exhaust plates or bottom seal
The engine has no spark - a loose wire either in the trigger or stator is touching ground or looses connection
The carbs has not fuel - faulty fuel pump or leaky fuel hoses and connections
The carb has fuel but nothing into the engine - carb idle ports clogged
 

roscoe

Supreme Mariner
Joined
Oct 30, 2002
Messages
21,842
Re: 50 hp force starts great when first in the water and wont start again.

You have all the classic symptoms of a bad/leaking/torn fuel pump diaphragm.

Fuel leaks into the crankcase and causes a flooded condition.

Get a fuel pump rebuild kit from any Mercury dealer and fix her up.

Or you can get the generic kit here on iboats.
Should be about $20
 
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