NJ Saltwater Fisherman Forums

Boating => Mechanical Forum => Topic started by: roscopico on August 11, 2008, 11:01:48 AM

Title: What you think, 40 HP YAM F40TLRA model
Post by: roscopico on August 11, 2008, 11:01:48 AM

Engine does not want to run on idle.
Will start only on the high idle remote.
Will push the boat on low speed, when I push for high speed it cuts off.

my conclusion: fuel/vacuum/carbs issues here.

1- If its running on high idle, then carb is clean right.,there is no restriction. and its getting gas.

2- It ran in the water pushing boat on low speed. so we are getting gas, fuel pump is pumping.( low-speed for me mean, only can push the trottle half-way)

LOST:

Title: Re: What you think, 40 HP YAM F40TLRA model
Post by: Hotrod on August 11, 2008, 01:56:49 PM

Bad seals.  A rebuild is in order t^

Title: Re: What you think, 40 HP YAM F40TLRA model
Post by: roscopico on August 11, 2008, 03:10:26 PM

You mean the gasket are broken, and there is lost in the vaccum, probably in the high speed top carb.

Title: Re: What you think, 40 HP YAM F40TLRA model
Post by: roscopico on August 12, 2008, 07:02:09 AM

Come on guys, need more response here

Title: Re: What you think, 40 HP YAM F40TLRA model
Post by: Maritime Matt on August 13, 2008, 07:54:58 AM

Carbes or fuel injected? Sounds like clogged jets to me. I've lost tract how many carbs and fuel pumps I've done. That is a 4 stroke, correct?

Title: Re: What you think, 40 HP YAM F40TLRA model
Post by: wb on August 13, 2008, 11:16:20 AM

Outboards can be funny sometimes and throw you for a loop.

My buddy had a Johnson 90 same prob you describe he redid the carbs a couple times ran good only if you choked it

turned out his lower unit was seizing ever so slightly-- nothing really noticeable other than it wouldnt run past 1500r's 5hrug

first time I ever saw that--all the smart money was on carburetion problems

doubtful it's your LU, just an example that you may need to think out of the box here...

Title: Re: What you think, 40 HP YAM F40TLRA model
Post by: Maritime Matt on August 13, 2008, 09:46:58 PM

Wow, first time I ever heard of that one but with boats and salt water anything is possible.
I'll keep that one in my head. Matt.

Title: Re: What you think, 40 HP YAM F40TLRA model
Post by: Hotrod on August 13, 2008, 10:08:54 PM

Quote from: roscopico on August 11, 2008, 03:10:26 PM

You mean the gasket are broken, and there is lost in the vaccum, probably in the high speed top carb.

Yea.. ros..  either way  a carb rebuild should fix it t^
I had the same problem on another boat of mine.  like Capt Matt said.  clogged jets..  clogged something restricting fuel.

Title: Re: What you think, 40 HP YAM F40TLRA model
Post by: Reckless on August 14, 2008, 05:00:16 AM

 Could be electrical also. Bad coil condenser breaks down under load. Timing not advancing etc.

Title: Re: What you think, 40 HP YAM F40TLRA model
Post by: roscopico on August 14, 2008, 09:15:50 AM

Thanks guys, I will start with the high speed carb, and see what happens.