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Very hard to start when cold

donmega

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"Hi, I have a 1993 18ft maxum

"Hi, I have a 1993 18ft maxum with a 4.3L LX V6. Motor has about 500 hrs. Just recently when the motor is cold, i have to pump the throttle while cranking it over for at least 10 seconds before it starts, and when it starts, it bellows out white exhaust until it's warm, then the exhaust clears up. The motor doesnt run sparatically or anything when this happens. She runs perfect the whole time. Any ideas? thanks"
 
"What does the white exhaust s

"What does the white exhaust smell like? How long since you changed the impeller? Could be that there's not enough water in the motor from the last time it was run, due to the impeller not pulling much water into the system, then when the exhaust gases hit what is there, it turns to steam until more water replaces the air because of running it at higher RPM.

How long does the boat sit from run to run? If it's sitting longer than a week, the bowl could be dry and needs to be refilled, causing the long crank time."
 
i didnt jump out of the boat t

i didnt jump out of the boat to smell the exhaust to see if it might have been steam...it does not do this when the engine is warm... the boat onlt sits for a week at a time before its run again and never did that before..the upper half of the leg is brand new. Is it normal to crank and crank that much even if it has only been sitting for a week? Before all it would take is a pump or two to WOT and then leave it back at 1/4 to 1/2 throttle
 
"Matt; yur problem seems to be

"Matt; yur problem seems to be very common to the 4.3 with 4 barrel carb.
You should read an earlier topic titled "1993 4.3 LX Merc Cold Strat Problem", started by Mike S on 10-01-06. There is lots of good info in that thread, contributed by many knowledgable folks.
I cured the identical problem with my 1996 4.3 LX as detailed in my post of 10-11-06 titled "UPDATE; 4.3LX Cold Start Problem-Fixed"
My results have been excellent and cured the problem that has plagued my boat since new.
Good luck!
Rod"
 
"The upper may be new but the

"The upper may be new but the raw water pump is in the lower gearcase. Also, if the problem started immediately after installing the upper gearcase, the water tube from the lower to the upper may be cocked and not pushing water in the volume needed to cool effectively. If there was no odd odor (gas, burning oil, etc), it was probably steam. You didn't say if the boat was in the water or being launched but you should be able to smell the exhaust when you're near the transom.

If the impeller is going bad (and you didn't say how old it is), you can overheat a motor easily just by idling back to the dock. This allows the water in the motor to boil out, leaving air in the water jacket. The hot motor can heat-soak and cause the gas in the carb to boil into the intake and when it cools, the bowl now has less gas to start with, in addition to possibly fouling the plugs when you try to restart. Try cranking at WOT before pumping the throttle to see if it starts immediately. If it does, it's flooded. If it doesn't, you could have a clogged fuel filter. If you have an oil cooler on the raw water inlet hose, that may be clogged and should be checked frequently. No water in = cooked motor. I think the problems are connected."
 
"To add something to what Rod

"To add something to what Rod posted- have you had run-on issues with your motor? If you have, there are some threads that cover this, too and if it has been running on, it is related."
 
"thanks for the info guys...Ro

"thanks for the info guys...Rod: I did read that entire thread about the same problem I'm having but no one mentions anything about a ton of smoke/steam bellowing out of the exhaust until the engine warms up, which worries me the most. Wouldnt there be a proper way to fix the problem rather than rigging in a switch for the pump? dont get me wrong its a brilliant fix but there must be a proper way to do it right?

Jim: it's a 1993 leg (lower half only now)... i dont have any problems at all with over heating (yet)as I keep an eagle eye on the temp at all times...theres no problem with run on either... its a very smooth runniong engine, except for the pain in the ars starting issue"
 
"The temperature sensor wants

"The temperature sensor wants to be in water, which is a better conductor than steam. If you have an air bubble in a car, you'll probably notice that the temperature gauge moves quite a bit unless it's a damped gauge. If you don't have good raw water supply, your temp reading won't be accurate and you still haven't said how old the impeller is. Even if it's "only" 2 years old, that's too old. Do you have an oil cooler and have you checked to see if it has any blockage?

If you really want to see if the cooling water is getting in there, touch the exhaust manifold risers briefly to check whether they're really hot. If they're cool, it's working. If you can't touch them without burning your hand, it's not. Another way is by getting an IR thermometer (Harbor Freight has them for under $30, IIRC) and looking all over the motor for hot spots.."
 
"Matt,
Just wondering, is it


"Matt,
Just wondering, is it getting colder where you are located?
The extra crank time & fuel needed for starting could be nothing more than the engine needing more fuel to start because of colder weather.

Once started the choke is staying closed longer until the engine warms up which could cause the smoking.

Engines require more fuel when the air is colder and take longer to warm up in colder water.

Unless you live in a warm climate that has not changed much I'd run it for the rest of the season and see how it does next season.

If you feel this does not apply then check the underside of the carburetor for signs of leaking plugs under the float bowl.
If these plugs are there and leaking the fuel would drain out of the float bowl after a few days depending on how bad they are leaking.

Good luck."
 
"I would think that excessive

"I would think that excessive gas at startup would give off a strong odor. I agree with the long crank time sympton with cold weather, though."
 
the temp has been getting cold

the temp has been getting colder and more moist here (vancouver island)... i dont know if you assumed but I didnt mention that it is FWC
 
"heck no... we barely get snow

"heck no... we barely get snow here every year... the weather has beeN no lower than 13 degrees (C)

by the way, i took it out yesterday and had the same probpem except this time it fired up fine when cold, but then after an hour of cruising i parked it at the marina for 10 mins then when i went to leave again it wouldnt start for at least 10 more mins... i pumped it and pumped it, left the throttle wide open and finally there seemed to be enough fuel for it to start. Once started, it ran fine, except now one of the belts is squealing at low rpm... wtf!?"
 
"Matt; I wonder if the white s

"Matt; I wonder if the white smoke problem may be anti freeze from your FWC system leaking into one or more cylinders when you are shutdown. That scenario is what happens with cars and would point to a blown head gasket, or cracked head or block. Maybe you should check your compression numbers to try to pin that down.
Have you been losing coolant from the FWC cooling system?
Rod"
 
"Matt,
If I understand the la


"Matt,
If I understand the last problem it would seem it was flooded when you returned to start it.

When you pumped it you just made it worse.
After holding it wide open it cleared the extra fuel out and started. Did it kind of chug to life when it did start?

If so this would point more to a problem with a leaking carburetor. It sounds like the fuel is draining out and into the intake.

The next time you have it out and shut it down try going to wide open throttle instead of pumping it before you try to start it. If it starts faster then I'd have the carb checked for leaks.

As for the belt noise,the charging system was under a big load trying to charge the battery back up. This makes the alternator drag and the belt could slip.
With all the hard starting you have had it would be a good idea to check the condition of the belt as well."
 
Knowing it has closed cooling

Knowing it has closed cooling would have saved a lot of time and erroneous guessing.
 
"My bad Jim, sorry... Charli:

"My bad Jim, sorry... Charli: yes it seemed to chug to life... ill check for coolant loss... it's never been overheated and with this problem it still has good torque when coming out if the hole"
 
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