Trouble starting

[pd189]

I have a 1973 850 Mercury. The engine turns great but will not start unless the intake on the carberator is covered. Once it starts it runs great, but if you shut it down and let cool for more than 10 or 20 minutes, you have to cover the intake to get it to start again?? I'm at a loss..., I have folks mention reed valves, carbon build up..., I have no clue

 

[tashasdaddy]

Re: Trouble starting

are you using your choke, is it working? by covering the intake you are choking the motor. what exactly is your starting procedure.

 

[pd189]

Re: Trouble starting

Yes the choke seems to be working. When I try to start it, it just cranks and cranks until I physically place my hand over the intake and then it runs fine. Almost seems as though something internal is not opening or closing and have to create a vacuum for it to start.

 

[tashasdaddy]

Re: Trouble starting

those inline are known to be very cold natured. the ones i had, you had to almost flood to start them. pump your bulb up till it is hard, fast start full open, choke on, turn over 3 times, now go back to the bulb, and make it hard again, now put the bulb to where you can put your knee on it. and put weight on it. now try to start. thats how i have started many.

 

[Chinewalker]

Re: Trouble starting

You say the choke is working. Is it REALLY working? It is not uncommon for old choke linkages to develop some slop in them - enough so that they no longer choke fully. You might want to take a look at the choke butterflies when someone else operates the choke button to see if they are closing fully.
- Scott

 

[papasage]

Re: Trouble starting

the choke butterflies has to be fulley closed while cranking .have see some just push in on choke and release while cranking . i sat and watched a boater run his battery down . he was pushing in on choke several times . i could hear it click then he would try cranking it . had one that would onley crank on manul choke . mooved the choke cylinoid so it would fulley close it started with the eletric choke then.

 

[pd189]

Re: Trouble starting

Thanks for the suggestions. I am going to try them this weekend and see what happens...,

 

[pd189]

Re: Trouble starting

Anyone know where I can get a manual for this motor..., it's listed as a 73 Merc 850 4cyl 013...., s/n 4232238. I actually just bought boat used and was looking through some of the maintenance records.