Hard start when hot

[wellcraft cat]

Hello all, Im having a problem with my 165 merc 4 cyl. that Ive come across before on this board. While the motor starts right up when cold, it takes a lot of cranking to get it started after I went for a little run and shut it down to do some fishing. Now I thought I had it fixed when I replaced the float and needle valve which merc. actually calls a fix kit for the carb(hot drip Im guessing) but no still need to crank 10 sec of so after it warmed up. <br /> Vapor lock is a term I came across and I really dont understand what is LOCK? I know it can get really hot under the motor cover and the fuel line is sure to heat up but why the cranking? Also since this does not seem to be a problem created by ware and tare how does Merc get away with it? I guess Im looking for that worn part to make her new again there was mention of an anti-siphion valve in the gas line could that cause hot drip and are vapor lock and hot drip connected or two different problems. Sorry for the long story but I really need answers and the budgets getting streched

 

[tommays]

Re: Hard start when hot

i dont know what you have tryed but you need to be sure that it is fuel problem and not a ingition problem <br /><br />if your sure its fuel vapor lock is very common even in cars fuel boils at a very low temp and then the area is filled with fuel vapor and not fuel<br /><br />the best thing i can suguest is after the motor is warm and will not restart remove the flame arestor and have someone move the throtel you should see fuel being pumped out the acc pump nozzles each time time throtel is moved if its comeing out then you have fuel and that is most likely not the problem<br /><br />DONT RUN THE MOTOR WITH THE FLAME ARESTOR OFF<br /><br />tommays

 

[wellcraft cat]

Re: Hard start when hot

Thanks Tommays, I will have a look down the carb next time Im out by the way if the problem is (hot drip?) should I be able to see that too when I pull the flame arrestor arter a drive? I guess I forgot to mention I have replaced the rotor, cap, points, plugs, wires and ignition coil and float and needle the parts counter guy and I are on a first name basis

 

[Blk-n-Blu]

Re: Hard start when hot

Well, One thing you can do to help alleviate vapor lock when hot, is to cool down the motor after a hard run by letting it idle or just above idle for several minutes before shutting down. Just my $0.02

 

[NYMINUTE]

Re: Hard start when hot

Open the gas cap slowly, if you hear/feel a release of air, it could be the issue. Had a truck do this routinely in the 80's. Kept the cap a bit loose and it helped.

 

[navigator336]

Re: Hard start when hot

Have you checked to see if the choke is fully open before trying to restart after a 10 minute shutdown?

 

[trebor0301]

Re: Hard start when hot

When I ran slow for a long time I would have the same problem.I found that running the blower motor or lifting open the motor hatch would keep the motor cool while taking long slow cruises.The motor compartment doesn't get much air thru the vents when idleing.Since doing that I have not had that problem again.

 

[wellcraft cat]

Re: Hard start when hot

Well I just thought Id write to say I had my carb rebuilt last week and it was worth every cent. The motor is running smoother and no more cranking when hot, YES! What a relief.<br /><br /><br />Now on to winterisation oh joy! Its supposed to cool down here in Philly next week