boat only starts with the carb cover off?

[jnmaricic]

Hello i got a 1983 mercruiser 140hp inline 4. Tryed starting it the other day with no luck until i took the top cover of the carb off then it started. So thinking that i had to rebiuld the carb i did and the same thing. I can loosen the screws of the cover and the boat will start. anyone have any idea? thanks

 

[Don S]

Re: boat only starts with the carb cover off?

The flame arrestor is probably plugged up with dirt and corrosion, clean it or replace it.

 

[jnmaricic]

Re: boat only starts with the carb cover off?

had the flame arrestor off when trying to start it. has a 2 barrel rochester

 

[Don S]

Re: boat only starts with the carb cover off?

I guess first we have to get some terminology understood.

What are you calling a carb cover? Got a picture?

 

[jnmaricic]

Re: boat only starts with the carb cover off?

don't have any pics but i took out about 8 to 10 srcews. the fuel line. opened it up and what im saying is the cover is what the top of the carb where the float is attached. when i put the screws back but loose the motor starts had it running and tighten the screws the motor cut off

 

[Don S]

Re: boat only starts with the carb cover off?

You need a new carb.

 

[jnmaricic]

Re: boat only starts with the carb cover off?

also put my finger over the gas line to stop the gas and just pour gas into the float well and the motor ran great

 

[mthieme]

Re: boat only starts with the carb cover off?

Not very safe.

 

[Bondo]

Re: boat only starts with the carb cover off?

Ayuh,... If you have to take the carb Apart to make it run,..You need a New Carb...
Or,..
You Screwed up the carb Rebuild.. Big time...

 

[45Auto]

Re: boat only starts with the carb cover off?

As Don says, you need a new carb. Most likely the feed jet passages are plugged up. When the screws are loose its probably letting gas leak into the venturis between the carb top and the carb body, same way it's running when you pour gas straight into it.

 

[chiefalen]

Re: boat only starts with the carb cover off?

Don't know if you knew this but carbs rebuilt have a 50 / 50 chance of ever giving good service after being rebuilt, and that is if a guy who knows what he is doing, does the rebuilding.

So that being said and that carb is a very, very common carb you can get a rebuilt one from a pro, local and pay about 175- 200 dollars for one, or go on ebay i just saw a bunch for sale new.

But that carb you have now should go for a one way trip into the trash can, or maybe keep it and use the odd part off it.

While your waiting for the new carb test the fuel pump 4-6 psi is what it should be giving you.

 

[fat fanny]

Re: boat only starts with the carb cover off?

Just asking but is it just possible that the carb wasn't cleaned correctly before reassembly? and now these issues arise from that problem? Orparts installed incorrectly?

 

[mkast]

Re: boat only starts with the carb cover off?

Just asking but is it just possible that the carb wasn't cleaned correctly before reassembly? and now these issues arise from that problem? Orparts installed incorrectly?

YES
YES
YES