mercury 40hp won't start

[tomko]

I have a 40 hp mercury that won't start,but if I spray gas in the carb it starts and runs fine.I disassembled the carb and cleaned it. The primer bulb and fuel lines seem ok.Could my problem be in the engine?

 

[Moody Blue]

Re: mercury 40hp won't start

Before starting the engine are you choking it?<br />What year is the motor ? Electric start or manual ?

 

[Vlad D Impeller]

Re: mercury 40hp won't start

Hey tomko, check out the FAQ section in the forum, there is a process of elimination on your delema

 

[tomko]

Re: mercury 40hp won't start

My engine is a 1983 ser. no. 6084573 with electric start. I try choking it and it doesn't help. I found something else that may be the problem. The gasket on the cylinder block is leaking. I sprayed carb cleaner on the seam with the engine running hoping to see bubbles or maybe hear the engine rev up to confirm the leak,but instead the engine stalls. It happens everytime so it must be a bad leak.

 

[Moody Blue]

Re: mercury 40hp won't start

What gasket ?

 

[tomko]

Re: mercury 40hp won't start

I changed the two cork gaskets on the cylinder block cover. The engine will now start without spraying gas in the carb,but it still isn't right.I have to advance the throttle and choke it everytime I start it. Could someone give me the procedure for checking the timing? I want to check that I got everything back together right. I'm also thinking maybe the fuel pump,thanks.

 

[Moody Blue]

Re: mercury 40hp won't start

Do a search for "sync and link" or vis-versa. THere is an excellant summary that one of the members wrote up. Sorry can't remember who the author was.<br />The fuel pump is simple to do and inexpensive parts wise. Probably a good idea if for no other reason than to eliminate it from the equation.

 

[tomko]

Re: mercury 40hp won't start

I tried to check my timing using Clams Canino's post on timing and sync,but the timing marks on my flywheel don't line up with my pointer. They are off about 90 degrees. When the no. 1 cylinder is at tdc shouldn't the pointer be at 0 on the flywheel? With the no. 1 cylinder at tdc I removed the flywheel from the hub and tried to set it at 0 with the pointer,but it wouldn't line up. With the marks set as close as I could get them to the pointer I started the engine but it wouldn't run very well.<br />I put my own marks on the flywheel and the approximate settings I got were at idle 11 btdc,at the first throttle pickup 17 btdc, and at wot 34 btdc.<br />How could the marks on the flywheel be off so much? I don't want to adjust anything yet. Thanks