need advice

[tontoyoder]

This is my first on here not good with computer so i hope it's in the right place . I have a 1970 mercury 800 thunderbolt ignition It is very hard to start at first I have to spray fuel in cylinder to start once it starts it seems to run fine but if it sits for about an hour or so it won't start again without spraying fuel again i have tried it after about 20 min. and it starts like new any advice
great thanks

 

[Laddies]

Re: need advice

If the engine is spinning well as low voltage will cause that problem, then it sounds like a lean idle condion. First make sure thee choke is closing completely and is seated well against the carb throats, next try to richen the idle mix 1/2 turn on each carb and if that don't wotrk pull the carbs and clean them, checking the float hieghts and installing new inlets.

 

[bullbat]

Re: need advice

sounds like to you need to clean and rebuild the carbs

 

[Moody Blue]

Re: need advice

Two questions for you.

1) Are you using the choke to start the cold engine? You must push AND hold the choke button while cranking the motor. These motors NEED lots of choke to get started.
2) Have you verified, as Laddies suggested, that the choke is actually working properly when you press the choke button?

The fact that you can get it started by spraying fuel into the carbs suggests the choke is not working right. I have the same motor and same cold start issues. Choke, choke and more choke.

 

[tontoyoder]

Re: need advice

thank you for responses, I have checked the chokes and all seems to be working properly. The motor also has a manual choke on it and I have tried it and watched the shutters cover the opening and it seems to fit snug
I am in the process of ordering a manual and getting what I need to rebuild the carbs if anyone has used the manuals on cd that are on ebay info will be greatly appreciated thanks again to all for input.