Expert: Jeff Grigg - 1/21/2008

Question
QUESTION: Hi Jeff,
I have a 1977 Mercury 1500 outboard 150 HP. It did seem to run fine at low speed but had no top end. (would only reach a top speed of 15-20 MPH) I have a Seloc manual. And was going through the timing and synchronizing section. I tried to follow procedure and now it will not start.
This is what the manual states.
BELT TIMING
“ Remove the power-head cowling. Remove all of the spark plugs as a safety measure. Observe the single dot (three dots on models 1150 and 1500 prior to 1978) alignment mark on the flywheel and the arrow cast on the distributor pulley. Remove the bolt, washers, pulley cove, and the belt. Now, rotate the flywheel clockwise until the alignment mark on the flywheel is aligned with the center of the distributor shaft.
  Rotate the distributor pulley until the arrow is pointing at the flywheel alignment mark. Hold the pulley in this position and install the belt. Install the pulley cover, washers, and bolt Torque to 60 in lb.

My question in regards to this is (I have 3 dots on my flywheel 2 are together and one is by itself, they are on the edge of the flywheel are these the dots referred to?) what dot do I use?

  TIMER POINTER ADJUSTMENT
  “ Install a dial indicator into the No.1 spark plug opening. Slowly rotate the flywheel clockwise until the No.1 piston is at top dead center. Set the dial indicator at 0. Slowly rotate the flywheel counter clockwise until the dial indicator needle is approximately ¼ - turn beyond the .464 mark. Now, slowly rotate the flywheel back clockwise until the dial indicator is at exactly at .464.
  Adjust the timing pointer until the pointer is aligned with the .464 mark on the timing decal. Remove the dial indicator. Install the spark plugs. ”

My question here is what is the .464 mark on a dial indicator? And what is meant by “ dial indicator needle is approximately ¼ - turn beyond the .464 mark. ”

Thanks for your help,
David


ANSWER: David, the timing on an inline is not that difficult, IF you know what you are doing. For the boat owner or backyard mechanic it can be intimidating, to say the least. On your flywheel there should be three small drilled/punched dots on the side of the flywheel facing you. Not on the ring gear. This aligns the dist to the flywheel.
The .464 is used to align the timing pointer and put it in the proper place.
Mercury uses a dial indicator tool to measure in decimals where the crankshaft is in it's rotation.
Without the dial indicator, with the proper adapters, you can not do this part of the job.
I would highly recommend you call around to the various shops and Mercury dealers to see if any of them has someone with experience working on the inline dist. motors. Don't trust anyone under about 45 to 50 years of age! Most have no experience.
Have them set up the timing on your motor.
Post back with your city, I may be able to put you in touch with some inline enthusiasts that can also help you.
Jeff

---------- FOLLOW-UP ----------

QUESTION: Jeff I am in the Stuart Florida area. I would like to do this myself and am sure I can if I can understand what needs to be done.
Thanks for your quick responce
David

Answer
OK, go to your local Mercury dealer and buy a dial indicator with the adapters for use in a spark plug hole.
Align the 3 dots on the side of the flywheel with the center of the distributor. At this time a tang on the dist. pulley will align with a tang on the mounting flange of the block. Slip the timing belt over the pulley. If it won't align perfectly it will if you go 1/2 tooth off. Follow the service manual.
Install the dial indicator and find TDC. Check that the timer pointer is pretty close to the decal's TDC. Now set the dial indicator at .464 before TDC. Do this by turning the flywheel backwards past the .464 then gently bring it to the .464 on the indicator. The pointer on the engine should be pointing to the .464 on the decal. If not move it to align it.
Now you can time the engine. With the shrouds and dist. pulley top plate installed you can start and run the engine. Do this with the lower unit in the water, NOT on a hose. You don't have to take the boat off the trailer.
With an inductive timing light time the initial pick up timing to the specified timing. You can fudge the timing up a degree or two if necessary.
If the engine stalls, make sure your idle mixture adjustment of all three carbs is open 2 turns from lightly seated.
When you do your WOT timing time the engine to NO MORE than 21*, preferably 19*. This is due to the changes in fuels since the engine was manufactured. Set the timing and synchronization by your service manual.
Jeff