HOW DO YOU TIME a 1979 115 mercury

[paul tracy]

was wondering if any one could explain how to time these motors? I'v got my motor apart for the second time this week. Keep bunning up my rings, could i be running it to lean or rich? another thing is it's so hard to start and after awhile of going it starts fine! i don;t understand

TO TIME IT ; should the number 1 piston should be up flywheel top dead center.but distributor cap is not in line, now i had the throttle all the way back where should the throttle be at when timing it, forward or backwards

 

[emckelvy]

Re: HOW DO YOU TIME a 1979 115 mercury

Here's a link to the writeup for doing so:

http://forums.iboats.com/showthread.php?t=168855

HTH..........ed

 

[79Merc80]

Re: HOW DO YOU TIME a 1979 115 mercury

Thought you should know that a 79 and newer doesn't have a distributor. If you post the serial # we can let you know the year.

Craig

 

[roncoop75]

Re: HOW DO YOU TIME a 1979 115 mercury

Thought you should know that a 79 and newer doesn't have a distributor. If you post the serial # we can let you know the year.

Craig

They changed to distributorless in MID '79. A '79 could still have a dist.
http://forums.iboats.com/showthread.php?p=2432918
Post #14 and again mentioned in #18.

 

[scottybm1]

Re: HOW DO YOU TIME a 1979 115 mercury

Sorry to hijack but I have a Mariner 115 on a 1980 Jetster, I thought it was a 1980 motor but it does have a distributer. I haven't checked the serial number but was wondering if they were the same motor.
Thanks
Scotty

 

[paul tracy]

Re: HOW DO YOU TIME a 1979 115 mercury

haven't had a chance to look at my model number but mine is 115 hp 1979 thunderbolt with distributor!

 

[Chris1956]

Re: HOW DO YOU TIME a 1979 115 mercury

Paul. There is a FAQ on how to link and sync a Merc inline motor. On your model, you first need to set the timing pointer. To do this set the top cylinder to Top Dead Center (TDC). Now stick a ruler or better yet, a caliper or dial indicator into the cylinder. Back off the flywheel until the piston recedes .464 Inch. Set the timing pointer to read .464 on the decal. OK, now run the link and synch procedure, using 4-6* BTDC for the idle pickup timing. There is a moveable brass collar about 1/2 way up the distributor body. This is adjusted to make the idle pickup specification. Max timing is 21* BTDC.