Idle and timing question 1970 Mercury 1150

[Ricky_rich]

I'm having problem with to high idle on my engine. Carburetors are all closed but engine rpm is rising to high level.
I wan't to check with you guys that I have the timing right. I have set the three masks on flywheel against the arrow on alternator pulley at TDC. When running the engine and using a strobe on cyl 1, I get a reading as the attached picture shows. The three marks are at approximately 18 degrees and the line to the right next to it at about 38 degrees. I know my scale is unreadable but I have compared it against a good one. So is this correct timing for my engine?

 

[Chris1956]

You see the heavy line near 4* BTDC? That is where the idle pickup timing should be set. So move the throttle all the way closed. Make sure the carbs are all closed. Now advance the throttle until the carbs are about to open, but are still closed. Now start the motor in neutral on the flusher. The timing at that point should be 4-6* BTDC.

I am not exactly sure what ign system you have , but, Max timing on a Thunderbolt Battery powered CDI ignition is 21* BTDC.

 

[Ricky_rich]

You see the heavy line near 4* BTDC? That is where the idle pickup timing should be set. So move the throttle all the way closed. Make sure the carbs are all closed. Now advance the throttle until the carbs are about to open, but are still closed. Now start the motor in neutral on the flusher. The timing at that point should be 4-6* BTDC.

I am not exactly sure what ign system you have , but, Max timing on a Thunderbolt Battery powered CDI ignition is 21* BTDC.

I have tried this but the line on the flywheel is still around 38. And idle is way to high.
I have attached a picture of my distributor; I believe it's the original one. But I'm wondering about the TDC setting. I cannot get the marks to line up right. If I set piston one TDC, three marks on flywheel against arrow on distributor pulley. Then I have the rotor between cables for cylinder one and four. This cannot be right??
But if I line up the two marked with arrows then I get the rotor to point and cylinder one cable. But then the arrow on pulley is off. But the important thing here is to have rotor pointing at cylinder one when set to TDC right?

 

[Chris1956]

Well, That motor looks to have Battery-Powered CDI Ignition. I cannot explain what you are seeing, but have some suggestions. First check - turn the flywheel until the top piston is at top dead center. Just use a screwdriver to set the piston to the top of it's travel. Now read your timing decal. It should indicate very close to TDC. If the timing decal indicates plus or minus 45*, the outer flywheel is on wrong. See those 4 bolts around the flywheel nut? There should be 8 bolts. Perhaps someone installed the outer flywheel wrong?

 

[Ricky_rich]

I have now done the following.
Piston 1 set to TDC, flywheel mounted with the three dots lined up with the TDC mark on timing decal. The thick line to the right, canot be lined up with TDC mark on decal. Distributor belt put on so the two marks line up together and rotor pointing right at cylinder one cable. Then checked that I have a spark on all the plugs. By using a strobe on cyl 1 I get a reading of 4 BTDC, with throttle advanced to the point just before the carbs are about to open. But engine will not start, I hear it fires now and then but cannot get it running. If I advance the throttle a little more I get a reading around 8 BTDC. So I guess this part is working.
The strange thing is that I could get the engine going before, with the alternator belt put on so I had a much more advanced spark. But then way to high idle.
The four screws on flywheel is just me not having the effort to put them all back, when changing distributor belt configuration.
Thankful for any advice.

 

[Chris1956]

Well, it sounds like you timed it properly. Spray some fuel into the carbs, close the choke plates and crank her up. Advance the cold start lever as well. Maybe she is not choked enough to start cold.

 

[Ricky_rich]

Yes the timing must be correct now. But the engine will not start, unless I spray some fuel into the carbs. Then it will run for a few seconds. So now it looks like I have a fuel problem.
What do you think, is the first steep to dismount the carbs and go through them? I have rebuilt the fuel pumps with new diaphragm, gaskets, & check valves.

 

[Chris1956]

Yes, it sounds like the idle passages in the carbs are clogged. There are sometimes small pin sized holes in the throat of the carb. These are important for the idle circuit, and clog easily. Make sure you get 'em clean.