cold flooding

surlyjoe

Chief Petty Officer
Joined
Nov 21, 2005
Messages
486
my 1960 40 horse floods when starting dead cold, no choke or throttle and it still has to crank out some gas before it gets going. after a minute or so of sputtering and gassing up the launch area, it finally catches and runs great.once its been running, it starts up first crank, unless its been off for over an hour, even then its not nearly as difficult and usually grabs in the first 5-7 turns of the flywheel . I have rebuilt the whole motor sans lower unit, and re-epoxied the float when I rebuilt the carb, also made sure the float level was right. new needle and seat as well.. 125psi on both barels.<br />any attempt at chokeing or high Idling just makes it worse..<br /><br />could this be from a too rich setting on the idle adjustment? I am at only about 3/4 turn out now and am kind of afraid to clamp it down until I get the smoothest idle, as i dont want to run it lean and smoke all my new parts..<br /><br />any Ideas?
 

Paul Moir

Admiral
Joined
Nov 5, 2002
Messages
6,847
Re: cold flooding

Does pumping the primer bulb after the engine has been started affect the idle at all?<br />I'm wondering if either the fuel pump diaphram is leaking, or if the needle & seat are leaking a bit due perhaps to the float sinking a bit with the extra weight of epoxy.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: cold flooding

Any epoxy added to the float increases its weight which affects how high it floats. Therefore, the standard setting may no longer be accurate since the float will now sit lower which raises fuel level in the bowl, making a rich condition. That would not necessarily create a problem at high speed but would certainly be a problem at low speed. Yes, incorrect mixture adjustment will also cause richness at idle. Proper idle will not hatch anything. Adjust for best idle (engine in the water, not on muffs). See if that helps. If not, there are other carb issues.
 

surlyjoe

Chief Petty Officer
Joined
Nov 21, 2005
Messages
486
Re: cold flooding

no, and theres a new diaphram in the pump/cutout switch as well.<br /><br /> could this be from towing tilted with gas in the bowl? seem like it would just run out the throatt if anything<br /><br /><br />I bet I am just afraid of a proper mixture....
 

surlyjoe

Chief Petty Officer
Joined
Nov 21, 2005
Messages
486
Re: cold flooding

I used thinned epoxy on the float and brushed it on as Thin as I could, I tested the needle and seat when not running, it holds pressure once the bowl is full. should I drop it a little to compensate?
 

Paul Moir

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Nov 5, 2002
Messages
6,847
Re: cold flooding

With adjustable high and low speed controls IMO float level is not critical. As long as it's holding pressure fine. I think you would have to be pretty lax applying the epoxy to get it too heavy.<br /><br />When you rebuilt the carb, did you replace the big fiber washer that goes over the main jet? I think the 40hp carb had one.<br /><br />Which choke mechanism do you have on your 40hp? Is it the heat choke, water choke or manual choke? Are you defeating it?<br /><br />Don't worry too much about the idle mix being too lean. You'd have to be pretty negligant to have that damage your engine. It'll sneeze and hesitate when you hit the gas if it's too lean on the idle. Even with the high speed improperly set, it's hard to murder a Big Twin.
 

surlyjoe

Chief Petty Officer
Joined
Nov 21, 2005
Messages
486
Re: cold flooding

thanx dood! ya, I got the full rebuild kit, but couldn't find one with the float, so the main washer is new.<br /><br />It's got the manual choke, so no secrets there. <br /><br /> I am convuncing myself I have the mitures too rich. even tho it seems like the needles are way in according to what Ive read here and in the manual. I know the Idle will still come up if I lean it out a bit, so...<br /><br />we're out fishing tomorrow, so I will get my m8 to drive and tweak some knobs!!<br /><br />nice to hear that they are tough motors!
 

surlyjoe

Chief Petty Officer
Joined
Nov 21, 2005
Messages
486
Re: cold flooding

well, I was out sunday, and my m8 was driving, after we stopped for beer, he punched it out of the 5-mph zone and it wouldnt plane. I yanked the carb back off, and procured a real OMC (not sierra) rebuild kit with a new float, so I am gonna try that and I will let you know what happens
 

surlyjoe

Chief Petty Officer
Joined
Nov 21, 2005
Messages
486
Re: cold flooding

well,I rebuilt the carb again with a real OMC kit and new float, there was a spring missing on the choke linkage, so i got that as well, but still cant use the choke and it still seems like its flooding out when trying to start cold..
 

R.Johnson

Rear Admiral
Joined
Sep 24, 2003
Messages
4,446
Re: cold flooding

On your engine there is feature called cruise throttle. This is a heavy wire link arm that run's from the throttle tower shaft to the carb link. Back by the tower shaft, and on the wire link, there is a small brass furrle with a set screw. When you pull the throttle back, the carb throttle plate goes partially closed, but he mag plate stay's at full advance. If the brass furrle is not adjusted propely, the carb will open to early, and cause a starting, and idle problem.
 

surlyjoe

Chief Petty Officer
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Nov 21, 2005
Messages
486
Re: cold flooding

I know exactly what your talking about, I dont think I ever moved it so it probably isn't right. any advice on adjusting it ?
 

Paul Moir

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Nov 5, 2002
Messages
6,847
Re: cold flooding

You set it so it just takes over after the armature plate hits it's stop, so that as you continue to throttle up the armature plate stays stationary, but the carburetor continues to open. This is fuel guzzling territory. :) <br /><br />I've got the "by the numbers" instructions here somewhere. I'll try to find them.
 

BoatBuoy

Rear Admiral
Joined
May 29, 2004
Messages
4,856
Re: cold flooding

Paul, does that mean that the throttle plate does not begin to open until full advance is achieved?
 

OBJ

Supreme Mariner
Joined
Dec 27, 2002
Messages
10,161
Re: cold flooding

The throttle cam opens the plate so far up to full advance, around the neihborhood of 1/2 to 3/4 open. The rod opens the throttle plate the rest of the way.
 

R.Johnson

Rear Admiral
Joined
Sep 24, 2003
Messages
4,446
Re: cold flooding

To adjust! Remove the remote control throttle cable. Loosen the set screw on the link rod. Push the throttle lever to full advance. Push on the back of the link rod to open throttle plate to full position. Push the brass keeper again'st the tower shaft, and tighten the set screw. Work back, and forth to make sure you have full throttle, you may have to tweek the keeper a little either way to get it right. Three hand's are a plus here.
 

surlyjoe

Chief Petty Officer
Joined
Nov 21, 2005
Messages
486
Re: cold flooding

OK, Thanx guys!! I think I have the jist of it, I am off to score a minn kota 30 for $40 this morning, but I will mess with it as soon as I get back
 

surlyjoe

Chief Petty Officer
Joined
Nov 21, 2005
Messages
486
Re: cold flooding

well, I fired it up on the muffs this morning after screwing with it yesterday and it fired right up, even the choke seems to be working now, so problem solved!! Thanx again for all your help!!
 

surlyjoe

Chief Petty Officer
Joined
Nov 21, 2005
Messages
486
Re: cold flooding

well, I fired it up on the muffs this morning after screwing with it yesterday and it fired right up, even the choke seems to be working now, so problem solved!! Thanx again for all your help!!
 

surlyjoe

Chief Petty Officer
Joined
Nov 21, 2005
Messages
486
Re: cold flooding

after getting it out on the water 8 or 10 imes, I it would seem it was a combination of having the carb set way too rich, both high and low, as well as my ineptitude at starting old outboards.<br /><br /> it now starts half choke and half throttle first crank even on the coldest mornings, and gets alot better fuel economy.. :rolleyes: <br /><br />thanks again guys!!
 
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