Mercruiser 3.0lx help with timing

[maxum1700]

Hello all! I have a 1995 Maxum 1700SR with a 3.0lx mercruiser. I just put a new head gasket on. When I put in base time with the proper tool. I set the timing at 1 BTDC. The manual then says to remove and timing should be at 12 BTDC. I spent two hours everytime I set it to 1. Remove timing tool and plug in switch it jumps to way past 12. And idles at like 1500 rpm. So finally I set the timing at 12 at idle. Then performed the carb adjustment per the manual. She runs good now!​

However I am still concerned. This would be the second head gasket. The last one blew because I didn’t use the timing tool and just ran. Anyone have this problem? When I was running her at about 32 mph she was running about 3400 rpm. I feel like I still have throttle but didn’t want to push her.
Any advice would be great. I have engine serial if you need it. Using 13 service manual.
Thanks​

 

[alldodge]

Idle rpm is essential 650-700 rpm when setting timing
IF idle rpm was correct you should be good

 

[havoc_squad]

Hello all! I have a 1995 Maxum 1700SR with a 3.0lx mercruiser. I just put a new head gasket on. When I put in base time with the proper tool. I set the timing at 1 BTDC. The manual then says to remove and timing should be at 12 BTDC. I spent two hours everytime I set it to 1. Remove timing tool and plug in switch it jumps to way past 12. And idles at like 1500 rpm. So finally I set the timing at 12 at idle. Then performed the carb adjustment per the manual. She runs good now!​

However I am still concerned. This would be the second head gasket. The last one blew because I didn’t use the timing tool and just ran. Anyone have this problem? When I was running her at about 32 mph she was running about 3400 rpm. I feel like I still have throttle but didn’t want to push her.
Any advice would be great. I have engine serial if you need it. Using 13 service manual.
Thanks​

I would say that the idle speed screw setting needs to be adjusted close enough to get you to the need 750 RPM i'ish range on the trailer. Afterwards you might also need to do the idle fuel/air mixture if it is wrong.

Make sure timing is set per the factory manual using base timing mode, then afterwards you need to get the idle speed screw adjusted down to 750 RPMs with it in normal timing mode to match what the specifications are saying on the correct timing at idle. Then look at the timing on the motor to make sure it is close to what the mercruiser service manuals specifies for the serial number motor you have.

Do not set the timing when the motor is in normal timing mode. Otherwise you will possibly do damage again to the motor at high RPM.

Adjusting the timing of the motor of a Delco EST electronic ignition in normal timing mode defeats the purpose of base timing mode, which is to make sure the timing is set correctly to match the RPM of the engine.