Playbuoy

I am wanting to rebuild the carbs on my Cigarette Cafe Racer. The boat runs like a top but starts hard if the boat sets for more than a week or after running hard. I believe the hot start is most likely due to vapor lock. Not sure when the carbs have been rebuild last and am wanting to freshen them up. I am running twin 502's. The carbs are Holley double pumpers...I believe 800 or 850's. Local machine shop wants $125 labor plus $50-70 for the parts kit. How difficult is the rebuild and how do I clean up the appearance of carbs to make them look new? Thx

AllDodge

iTrader: (1)

You do not have a vapor lock issue. Vapor lock is caused when the fuel gets so hot it boils and there is nothing to be burned because it is nothing but vapor. If the boat sits long enough to become cold (room temp), vapor lock is not the issue. If the boat sits long enough you could have evaporation from the fuel just evaporating over time. Many carbs have this issue, it's just the nature of the beast. You may have a leak which is leaking fuel out of the bowl over time, but this depends on amount of time, outside temp and air flow.

If the engine starts fine once started then you could get a jump by having the fuel pump run a bit before you hit the key the first time

Katanna

iTrader: (1)

The running hard could be caused by fuel leaking into the intake and flooding. Look down your carbs next time you shut it off and see if fuel is puddling.

Playbuoy

I understand the concept of vapor lock. If the boat sets for a long period of time (i.e. 2 weeks) it is hard to start. I pump the throttles 3 times, crank the motor, fires up, but spits and sputters, then dies. I have to constantly work the throttles to get it to stay running. Once running it is fine. If it sets overnight I pump the throttles 3 times and it pops right off the next morning. If we go for a long run then shut her down, when I go to restart when warm it seems a little finiky as well. That is where I believe the vapor lock may come into play. Not 100% positive but I believe the boat has mechanical fuel pumps. There is 2 toggle switches on dash labeled "fuel stb port" but previous owner said not to mess with them.

Griff

Carbs do not vaporlock.

Do the carbs have chokes??? Because it sounds like a choke issue.

You better find out what those 2 switches are for.

Playbuoy

Thanks Griff...I did not realize carbs cannot vaporlock. I always thought when you ran hard it the fuel would boil out of the float bowl if engine hatch temps were high, thus turning the liquid fuel into vapor. I have not taken the spark arrestor covers off to verify if they are equipped with a manual choke. (I know it does not have an electric choke.) A choke issue would make sense. I was going to pull carbs next week when it warms up. When starting I give 3 quick pumps then crank. Possibly I am not pushing the throttles forward enough to engage choke if equipped. The fuel pump switches are never illuminated which leads me to think they are not hooked up possibly. I am almost positive I have seen a mechanical fuel pump on the side of block. Would the electric fuel pump come on when battery switch is on or key is turned on? I spoke with another mechanic and he says there is not really much to rebuild other than the accelator pumps on the Holley's. He states motor will spit and sputter is they are going out. He suggested I remove 4 small screws atop carb and blow out with Carb cleaner and call it good. I have seen a few small drips on top of my intake coming from underneath side of carb. Looks like and oil/fuel misture.

Unlimited jd

iTrader: (5)

Just about all cigs have the fuel pump switches. Some have the small electric pumps hooked to oil pressure switches. Some just have the switches. Need to look on the fwd bulkhead and see if the pumps are there.

FIXX

iTrader: (2)

try using non alchol fuels,,they also make a thermo plate that goes under the carbs to keep the heat from boiling the float bowls..i use this plata on all my performance builds..also i use a lifter vally shield to keep the oil from splashing in the bottom side of the intake.this will also boil the carberators..especially if you have a closed plenum intake,,non air gap style..

seafordguy

Do you leave those switches in the ON position? I would bet you have electric pumps like most of us do

I leave them in the on position and then when you energize the key they start running. One time last summer my 2 year old flipped them off andeft us stranded for 20 minutes until I figured it out.....

Griff

A bad accelerator pump will make the engine stumble and hesitate when giving throttle from an idle.
It sends an extra squirt of fuel for the transition from the idle circuit to the regular flow through the jets.
It does not do anything at actual idle.

It sounds like a choke problem or the carbs are just not adjusted properly.