Re: [OMC-Boats] engine wierdness

I tend to agree with the electrical suspect.  Fuel/air problems generally linger a bit and don't result in an immediate drop-out like you describe.  Anything is possible though.  I like the guidance Lee sent out awhile back where he said to eleiminate the possibility of electrical problems first since that's usually quicker and easier to do.  Trouble is, intermittent electrical problems can be a nightmare to trace.  Is there any possibility of hooking up some basic instrumentation to see if there is any electrical effect when it happens?  If you see a sudden voltage change or current drop out, that would be a clear indicator.  Good luck!

Andy

'67 Reveler

----- Original Message -----
From: "jd" <jdood@...>
To: "Evinrude & Johnson Boats of the 1960's and 70's" <omc-boats@...mate.com>
Sent: Thursday, October 29, 2009 11:44:16 AM GMT -05:00 US/Canada Eastern
Subject: [OMC-Boats] engine wierdness

took my boat out for the last of possible testing this season before  
things get too cold and rainy.      didn't go as i hoped.      i'll  
try and condense this down to it's simplest form:

BEFORE (about a month ago):

except for some slightly fast idling,  engine ran well.   Then I  
noticed it starting to do this weird intermittent thing where all the  
power (throttle) would just drop down to zero.  It seemed to happen  
mainly during acceleration up to plane.   This all was happening at  
the end of the season,  so I have pretty much had the boat sitting for  
the past month waiting for parts and time.   But I was thinking it was  
related to my falling apart carb  and / or and electrical thing  
related to my rebuilt shifter switch.   so......

AFTER  (yesterday):

- I installed my nice practically new carb (rebuilt by flying fish).    
keep in mind,  it was the exact same carb i have always had on the  
boat,  just completely rebuilt.  I also changed my air water separator  
cartridge beforehand to avoid any chance of issues from fuel that had  
sat for a month.

- I installed a NOS shifter switch that I recently acquired.   Tested  
with light after install, everything checked out.  And as I said,  
it's basically new.

So after those two major upgrades,  the engine is doing the same dang  
thing.    Started up,  let it warm up a bit,   took it for  a spin.  
About 5-10 seconds after getting up on that first plane everything  
just dropped down to zero and unlike the past times, this time the  
engine died at the same time.    Had to crank it over several times  
for it to start back up,  and when it did,   with the red lever set at  
full throttle it took several seconds for the RPMS to climb up to  
where they should be.   I limped back to the dock.

Then while at the dock idling for a  few minutes,  all of the sudden  
it just died again.    At idle this time,  not while accelerating.    
And every time it dies it is quick.   It's not like it sits there and  
slowly dies.  It just cuts out suddenly.   So I of course tried to  
restart it.  Nothing for several tries, then it acted like it was  
going to start,  then it finally starts,   coughing and sputtering a  
bit,  then  very slowly climbs up to full throttle (in neutral).      
I started thinking maybe a fuel pump issue.     Disconnected fuel  
line,  cranked engine,  plenty of pumping of fuel happening.

It seems sort of electrical in the way it just all of the sudden dies  
either at idle or accelerating.  Yet when it finally starts back up it  
coughs and sputters and smokes a bit.     Which sounds like bad fuel,  
yet I have a new water/fuel separator cartridge, the carb is new,    
and nothing looks dirty with the inline regular fuel filter.

Any ideas?

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Received on Thursday, 29 October 2009