Baffled trying to check 3.0L timing.

[harringtondav]

'88 3.0L breaker point distributor. Got the dwell close, and moved on to check and adjust the timing. I chalked the TDC notch in the balancer and 4 deg BTDC on the tab. I couldn't find the balancer mark with the timing light pick up on the #1 wire.

This is my good neighbor charity project. The boat ain't no virgin. My first thought is some previous hunyak pulled the distributor, replaced it out of time and set the timing by ear. Before I dive deep and pull the distributor to reset it to the #1 wire, is there something I'm missing? ...it's been 35 yrs since I've worked on a point ignition system.

Thanks, Dave

 

[Lou C]

That would make sense. I’d try marking the position of the #1 dist cap terminal on the dist body, then removing the dist cap and turn the engine over manually and watch the rotor position, it should come right to #1 when the mark on the balancer passes the tdc tab on the timing cover. If not someone may have installed it wrong.

 

[harringtondav]

That would make sense. I’d try marking the position of the #1 dist cap terminal on the dist body, then removing the dist cap and turn the engine over manually and watch the rotor position, it should come right to #1 when the mark on the balancer passes the tdc tab on the timing cover. If not someone may have installed it wrong.

Thanks Lou. BTW you were correct on the sensitivity of the 'chicken lips' shift rod height. I had it set w/in 1/32", and checked the shift rod cam notch position with the pivot hsg cam before attaching the drive. Seemed perfect.

I had to run the barrel nut on the lower shift cable nearly full rearward to get max travel on the lower cable, and cheat the upper shift cable back 1/4" in it's clamp to engage and hold in FWD and Rev. FWD was off by a mile.....er about 1/2". Same basic process as the Merc Alpha, and same basic PIA.

I'll pull my neighbor's drive again at the end of the year - over winter, split it and tweak the shift rod height a bit lower to favor the FWD position to get the cables centered back up. Any advice on the amount of height change to move the lower cable barrel nut forward 1/2"?

 

[harringtondav]

Well, I got it. Hard to believe but the #2 spark plug matches the balancer notch at TDC. Any distributor timed engine I've ever timed used the #1 plug wire as the datum. And this '88 3.0L OMC was severely advanced. I had to hunt for the balancer timing mark. When I retarded the timing to bring it into sight the engine almost stalled. Throttle screw in, timing retarded to to 4 deg BTDC, readjust throttle to 600 rpm, and home. Visual timing advance looked good with rpm increase.

Neighbor's boat charity project. I told the wife 10 minutes to reinstall the engine house. She knows to add another hour. Dwell is a bit too high, and I think I need to tweak the idle mixture screw. Then I'm ready to walk away. But once you've touched it, you own it. I told the neighbor about the problems with over advanced timing. Hope the craters in the top of his pistons hold for a while.

 

[Scott Danforth]

I normally adjusted dwell at cranking prior to dropping on the cap.

sounds like someone dropped the dizzy in wrong and its now 90 degrees from where its supposed to be.

 

[Lou C]

wow that is odd. I think Scott may be right.

 

[harringtondav]

wow that is odd. I think Scott may be right.

Scott Danforth . Yea, I figured Scott's theory and was getting ready to pull the dist. and retime the engine. I barred the engine over to match the balancer notch with 4 deg BTDC. Then used a screw driver piston TDC gage to verify #1 piston at top. Nope. #2 and #3 were at top, #1 & #4 were low, and the dist. rotor was pointing at #2 wire.

I visually timed the dist to breaker point opening, buttoned it back up, replaced the plugs and dialed the timing to spec with the timing light. The engine runs fine and the spark advances with rev increase.

The boat is 31 yrs old with an unknown history and list of owners. The only thing I can figure is someone replaced the balancer with an incorrect one.

 

[Scott Danforth]

nope, some idiot in the past pulled the dizzy and didnt stab it right