set points

[jim12063]

thanks for all the great information, like many I expect I would not be a boater without being able to DIY

re: 1988 Mercruiser 3.0L
I searched the posts but was not able to find this: how do I set the gap for the points? is it form the "low" point or "high" point? and how important is the exact gap? I actually got it running after installing- haven't gotten it on the water yet but it is running good- should I leave well enough alone?

thanks

 

[Eric 3.7LX Alpha 1]

Re: set points

Welcome aboard,
Read this link from the sticky at the beginning of this forum:

How To: Tune-up Your Engine with Points Ignition
http://forums.iboats.com/showthread.php?t=335302

that sticky is full of good info.

 

[Don S]

Re: set points

Setting point gap is done on the high points of the cam. But that is just a preliminary step before setting the dwell which is the angle in degrees that the points remain closed. It's very important if you want your engine to run it's best. You also have to reset the timing after setting the dwell. Dwell affects timing, timing does not affect dwell.

 

[mark1905]

Re: set points

I may get blasted for this, but if you're ever in a pinch and don't have a feeler gauge handy.. a paper matchbook cover works just about perfect. Come to think of it.. I don't ever remember using anything but on my first 1988 Merc 3.0..

 

[bruceb58]

Re: set points

You always want to use a dwell meter. It also allows you to see if your distributor bushing is worn if your dwell changes over varying RPM.

 

[stonyloam]

Re: set points

Amazon "Dwell Meter" about $25. Works fine, they have not changed in the last 40 years LOL.

 

[Silvertip]

Re: set points

Amazon "Dwell Meter" about $25. Works fine, they have not changed in the last 40 years LOL.

That's about how old mine is. Can't tell you when I used it last but probably on my 1970 Olds Delta 88 that I owned in the 70's. It pointed to a bad distributor bushing just as was described. Which reminds me, that incident was a head scratcher for a bit as the new set of points I installed had a loose contact on the stationary half of the point set. It would idle fine but the contact would bounce at higher rpm. Fixed that and then the dwell still varied but a check of the distributor shaft showed the wear.

 

[stonyloam]

Re: set points

The other nice thing is it includes a tach that you can use when setting idle, and as a check to your boat tach (mine was off by about 600 RPM). While we are talking about it, another sign of a worn distributor is if the timing is jumping around as you hold the RPM steady. Mine did, replaced bushings, now steady as a rock. Good luck.

 

[Oshkosh1]

Re: set points

The matchbook could be used to set both points(single cover...017) and gap plugs(folded over...035) on older engines.
Accutron makes a nice meter with both dwell and tach feature in addition to multimeter functions. I picked one up on ebay for about $15 in "like new" condition.

 

[bruceb58]

Re: set points

This is a timing light with dwell and tach included. Is also is an advance timing light.

http://www.amazon.com/Equus-5568-Pr...U8J8/ref=sr_1_5?ie=UTF8&qid=1336499801&sr=8-5

Still amazes me that people would use a matchbook cover to set dwell on an engine when setting specified dwell will be making your engine run at peak efficiency thus getting best mileage and saving potentially hundreds of dollares in fuel cost. Penny wide pound foolish!

 

[achris]

Re: set points

This is a timing light with dwell and tach included. Is also is an advance timing light.

http://www.amazon.com/Equus-5568-Pr...U8J8/ref=sr_1_5?ie=UTF8&qid=1336499801&sr=8-5

Still amazes me that people would use a matchbook cover to set dwell on an engine when setting specified dwell will be making your engine run at peak efficiency thus getting best mileage and saving potentially hundreds of dollares in fuel cost. Penny wide pound foolish!

I have one of those timing lights... They are B-R-I-L-L-I-A-N-T !!!! I would hope that anybody using matchbox lids for points gap is doing it as an emergency measure in order to get themselves home, not as the normal method to do the job....

Chris.....

 

[mark1905]

Re: set points

Exactly Not meant to be a permanent solution.. it was in a PINCH.. and dammit if the pinch always seemed to be at the wrong moments..

 

[Don S]

Re: set points

Happens all the time, boater out cruising around, suddenly the engine stops.

"OH MY" he says with panic on his face, "the points fell out of adjustment again, anyone got a book of matches so we can get home ????????"

 

[achris]

Re: set points

happens all the time, boater out cruising around, suddenly the engine stops.

"oh my" he says with panic on his face, "the points fell out of adjustment again, anyone got a book of matches so we can get home ????????"

roflmao....

 

[danielw71]

Re: set points

I did not have a dwell meter or tach. I found this one at Autozone for $40.00 Actron multimeter with dwell and tach part number CP7677:

www.autozone.com/autozone/accessori...26lr?itemIdentifier=431988&_requestid=1140425

 

[mark1905]

Re: set points

Happens all the time, boater out cruising around, suddenly the engine stops.

"OH MY" he says with panic on his face, "the points fell out of adjustment again, anyone got a book of matches so we can get home ????????"

Lol.. more like.. It's Sunday, boat loaded dockside, sunny day.. boat won't start. Fresh out of a feeler gauge and dwell meter. Rifle through the truck for a matchbook.. day saved. I'll take a Sunday boating day being saved anytime.

 

[bruceb58]

Re: set points

Lol.. more like.. It's Sunday, boat loaded dockside, sunny day.. boat won't start. Fresh out of a feeler gauge and dwell meter. Rifle through the truck for a matchbook.. day saved. I'll take a Sunday boating day being saved anytime.

Which is why you do preventative maintenance so that doesn't happen. Its also why I used to carry my dwell meter in my boat when I had a points style ignition.

Look at signature below regarding failing to prepare
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[mark1905]

Re: set points

I was prepared.. I had a matchbook, didn't I?

 

[Oshkosh1]

Re: set points

I did not have a dwell meter or tach. I found this one at Autozone for $40.00 Actron multimeter with dwell and tach part number CP7677:

That's identical to mine...works great so far.

There's probably some here who will flame it because it's not Snap-on or Fluke...whatever, however for the occasional use I think this is a reasonable option.

A matchbook is not the "right" way...however in a pinch, I KNOW it's gotten THOUSANDS of motrists home when "$#%t happens".

Most boaters are not mechanics. To MOST boating is a recreational activity...NOT a hobby, so to carry a dwell meter to them is tantamount to asking them to lug a spare engine around on a raft..."just in case".

 

[bruceb58]

Re: set points

Most boaters are not mechanics. To MOST boating is a recreational activity...NOT a hobby, so to carry a dwell meter to them is tantamount to asking them to lug a spare engine around on a raft..."just in case".

I also have a Fluke DVM that lives in the boat at all times. I used to carry a dwell meter along(when I had an engine with points) because I am often far from home when I use my boat.

I agree, setting points with a match book cover or feeler gauge for that matter is not the correct way to adjust them.