Question about Distributor Points

[LegacyT]

Im replacing the points in my distributor. The shop manual says the gap should be 0.014-0.019". Why such a wide range? Also, how do you adjust dwell on a presolite dist? Theres no window on it to adjust it like gm distributors while the engine is running. Do you have to play around with the contact gap to get the dwell within range?

 

[Maclin]

Re: Question about Distributor Points

...The shop manual says the gap should be 0.014-0.019". Why such a wide range? ...

That covers any worn items that can affect the actual opening of the points gap, like wear on the distributor cam, worn bearings or bushings in the shaft. Set it to the range then check dwell, adjust as needed. You can check the gap again just to measure it and see where within the range your distributor hits the dwell sweet spot and remember that for the next tuneup, gives you more of a chance of hitting the dwell range, might save some effort.

...Do you have to play around with the contact gap to get the dwell within range?

Yes.

 

[dennis461]

Re: Question about Distributor Points

Im replacing the points in my distributor. The shop manual says the gap should be 0.014-0.019". Why such a wide range? Also, how do you adjust dwell on a presolite dist? Theres no window on it to adjust it like gm distributors while the engine is running. Do you have to play around with the contact gap to get the dwell within range?

I loved my old Ford Mustang, but wished it had a GM distributor for this very reason.
It's a lot of work to get the dwell adjusted.
Trial and error: the purists will insist on the dwell being more important than the gap.

I adjust the points, make sure the engine runs good, and check the dwell with a meter.

 

[wicked pissah]

Re: Question about Distributor Points

yes you need a dwell meter to adjust however on ebay you can switch over to elc egn for around 70$ all my friends and i have all switched out boats over there is a company on ebay selling prestolit and mallory systems that drop right in but you have to change your coil and remove the resistor they are called hot spark on ebay

 

[LegacyT]

Re: Question about Distributor Points

Yeah I looked into it briefly. Was hoping I could just get the module but have to add a coil, another 50 bucks. I already have the points, so I'll stick to this for now. Are the ignition qualities really that much better with it though (like spark quality, timing etc)?

 

[Levinz11]

Re: Question about Distributor Points

Yeah I looked into it briefly. Was hoping I could just get the module but have to add a coil, another 50 bucks. I already have the points, so I'll stick to this for now. Are the ignition qualities really that much better with it though (like spark quality, timing etc)?

No. The only benefit really is ease of maintenance. It simply doesn't take 40-50,000V to ignite the fuel in our boats.

 

[Holy Shamolee]

Re: Question about Distributor Points

Put pertronix electronic on my 4 cyl volvo.
Took 3 minutes.
Best $100 bucks I ever spent.

 

[bruceb58]

Re: Question about Distributor Points

Use a dwell meter. You can crank the engine with the distributor cap off and get a fairly good dwell reading. There may be some degrees difference between what you measure running the engine and what you see cranking. With my dwell meter, it always measured a few degrees lower when cranking so you just need to figure out what the offset is and account for it.

 

[LegacyT]

Re: Question about Distributor Points

Got the new points in and adjusted the gap to get the dwell right in the middle of the recommended range. The boat runs and idles great for the most part, however it still pops/misses a lil bit at WOT. I have new points, condenser, rotor, cap, wires and relatively new plugs (20 hrs). I checked the timing and its bang on: 6* BTDC @ idle and 14* BTDC @ 2500 rpm. Coil is still original. Should I look into fuel delivery? Both separator and carb filters are new, but carb and fuel pump look original. Any recommendations?

 

[SteveMcD]

Re: Question about Distributor Points

Any recommendations? my electronic distributor was $400. Make sure your $70-$100 electronic ignitions are marine rated. Automotive parts have been known to make boats explode. That hasn't happened to me personally, but I'm sure that is not a good thing.

 

[Levinz11]

Re: Question about Distributor Points

Got the new points in and adjusted the gap to get the dwell right in the middle of the recommended range. The boat runs and idles great for the most part, however it still pops/misses a lil bit at WOT. I have new points, condenser, rotor, cap, wires and relatively new plugs (20 hrs). I checked the timing and its bang on: 6* BTDC @ idle and 14* BTDC @ 2500 rpm. Coil is still original. Should I look into fuel delivery? Both separator and carb filters are new, but carb and fuel pump look original. Any recommendations?

When I bought my old, but new to me boat I did all the tune-up stuff as well. After a completely new ignition system (other than the dizzy) it would still pop at WOT only. I bought a carb kit and now it's running just about perfect. You'll get it all dialed in.

 

[LegacyT]

Re: Question about Distributor Points

I measured the dwell while running. Checked the coil shes right in specs. Gonna rebuild the carb this winter as Levinz11 did.