VAPOR LOCK /FLOAT SETTING/TANK VENT

[CHEVYJEFF]

In the quest to figure out why my boat has hard starts when hot, I am confident its flooding when sitting due to gas smell. Since doing a massive search of this site and others. I have concluded that either my motor is experiencing vapor lock, a leaking well plug or a clogged tank vent. Here are my questions:<br /><br />1. How can I rule out vapor lock? I was thinking of insulating the metal fuel lines or putting a wet rag out of the cooler on the lines as a test next time I turn the boat off and create the hard start scenario.<br /><br />2. If gas is seen dripping down can I realease the gas filler cap and if it stops can I conlude the its a clogged tank vent?<br /><br />3. How can I determine if the well plugs are leaking down. Can they be seen from topside or will carb have to taken off pressurized and then tested.<br /><br />I have rebuilt the carb. checked and rechecked the float level, and drop per my mercruiser service manual and there are no visable leaks and I can shake the float and no gas is eveident inside. the boat runs great and starts cold just fine. I have also verified choke is working correctly<br /><br /><br />My specs.<br />1997 regal lsr 2100<br />5.7 mercruiser 210 hp 2 bbl mercarb<br />alpha one gen 2

 

[THE BEEF]

Re: VAPOR LOCK /FLOAT SETTING/TANK VENT

What kind of float does it have? Black plastic or brass.If its plastic pitch it and install a brass one.<br />Bill

 

[CHEVYJEFF]

Re: VAPOR LOCK /FLOAT SETTING/TANK VENT

Its the black plastic one also the boat never sees salt water so there is no corrosion issues in the carb body.

 

[THE BEEF]

Re: VAPOR LOCK /FLOAT SETTING/TANK VENT

The plastic ones have been known to get saturated with gas and start to sink lower in the bowl.<br />FLOODING <br />Bill

 

[bolo789]

Re: VAPOR LOCK /FLOAT SETTING/TANK VENT

iam having the same problem from last year. if you got the fix please post it so others can see thanks, mines just turnover real slow and weak but she start every time with the shifter push all the way. good luck

 

[CHEVYJEFF]

Re: VAPOR LOCK /FLOAT SETTING/TANK VENT

Originally posted by THE BEEF:<br /> The plastic ones have been known to get saturated with gas and start to sink lower in the bowl.<br />FLOODING <br />Bill

that sounds logical as the float could get a little gas here and there inside which then turns to varnish and therefore you cant hear it inside the float and making it heavier. It would also explain why its been a progressive problem getting worse over time. Any idea on a part number for that brass float?

 

[THE BEEF]

Re: VAPOR LOCK /FLOAT SETTING/TANK VENT

Get the number off the tag or on the side of the carb body and take it to a NAPA STORE thay can help.<br />Bill

 

[CHEVYJEFF]

Re: VAPOR LOCK /FLOAT SETTING/TANK VENT

its a p.o.s mercarb 2 bbl, dont think napa is going to have that float. I may just get a new plastic one if i cant find a brass one at plano marine.

 

[CHEVYJEFF]

Re: VAPOR LOCK /FLOAT SETTING/TANK VENT -UPDATED

Re: VAPOR LOCK /FLOAT SETTING/TANK VENT -UPDATED

update:
after checking float level once more to be sure, I took the boat to lake and eliminated the tank pressure theory.

I did however find that the boat did great until it got real hot. The temp gauge never gets over 180 but after sking for about 30 min. then stopping the gas in the fuel bowl is boiling. I looked down the carb and saw it dripping and I could hear it gurguling in the bowl. keep in mind it was 95 degrees out when these test were done

I also noticed the carb and fire arrestor were very hot to touch, I am going to order a plastic spacer to go between the carb and the manifold to try and reduce the transfer of heat to the carb.

I am considering, insulating my fuel lines and running a cooler thermostat to try and make the engine run cooler. The old cool can off the hot rod has me thinking too. One other thing that could be done is to block off the exhaust crossover in the intake manifold if its open.

Altough if I removed the mainfold to do this I will upgrade to 4 bbl and chunk this p.o.s mercarb.