4.3 longer cranking after sitting few days n when hot

Franco_boater

Petty Officer 2nd Class
Joined
Nov 2, 2021
Messages
116
Hello,
I’ve rebuilt my carb 4 years ago and basically I don’t have any issue. However I’ve noticed that after sitting for a few days like 5-7 days without boating it’s hard to start, I set the choke, add 2 full pumps of throttle and it takes some time time to start the engine (I crank for 5-10sec max to release the starter) or I need to crank for the 2nd time then it fires up.
After that it fires immediately, only the 1st start of the day is a little bit sluggish.
Same after boating and sitting for 30min to one hour i need to crank a little more but if I add throttle it fires up immediately I think it might be vapour lock?
How to diagnose it?

Thanks!
 

Scott06

Admiral
Joined
Apr 20, 2014
Messages
6,440
Hello,
I’ve rebuilt my carb 4 years ago and basically I don’t have any issue. However I’ve noticed that after sitting for a few days like 5-7 days without boating it’s hard to start, I set the choke, add 2 full pumps of throttle and it takes some time time to start the engine (I crank for 5-10sec max to release the starter) or I need to crank for the 2nd time then it fires up.
After that it fires immediately, only the 1st start of the day is a little bit sluggish.
Same after boating and sitting for 30min to one hour i need to crank a little more but if I add throttle it fires up immediately I think it might be vapour lock?
How to diagnose it?

Thanks!
You have a Webber carb ?

The float bowl will dry out I have same issue with my edlebrock when it sits you have to crank it for fuel pump to refill bowl

hot restarts the Webber edlebrock carbs are known to dribble fuel down to manifold creating a flooded engine opening throttle more to clear the fuel out will help
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
42,064
Not VL, it's the carb and for me I would just live with it

A carb sitting for a few days evaporates all the fuel from the bowl. When mine sat, I just crank for 10 seconds before even pumping throttle the first time.

Then pump, set choke and try again, just a carb thing

Now, once warm that can be carb is leaking fuel into the intake. Let it set after a run and remove the arrestor and look. If it's wet, most likely need to readjust the float level
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,291
A week of high temp will vaporize fuel from the carb and leave the bowls dry.Results in excess cranking .If you have an electric pump you can add a momentary switch to prime the carb usually installed in the eng compartment .
You do always open the engine compartment to sniff and look first ,right?
 

Franco_boater

Petty Officer 2nd Class
Joined
Nov 2, 2021
Messages
116
Yes i always check oil And open the hood before start and it’s MerCarb. Thank you
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
49,570
here in Florida, the carb will be dry in about 2 days from the heat during summer and about a week in the winter.
 

Franco_boater

Petty Officer 2nd Class
Joined
Nov 2, 2021
Messages
116
Ok thank I will see if its dry pumping the throttle at the 1st start of the day
 
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