1977 OMC se 300 sport w/ ford 302 175 hp. low speed idle problems

[tacconelli6]

timing

timing

OK! Set timing 10degree btc and dwell was @ 25 , idle rpms @ 600. It is still a little spuratic @ idle speed and will stall out after 5mins. or so. I didn't gap the plugs. So I am going to gap them all, increase the dwell angle and see where I'm at.

Could I have messed up this set of points from all of the adjusting I have been doing? Like touching them w/ the feeler when the key was still on

 

[chiefalen]

Re: 1977 OMC se 300 sport w/ ford 302 175 hp. low speed idle problems

You get a shock? Maybe it shocked you with enough sense to sell it and get a volvo ha.

 

[supercab78]

Re: 1977 OMC se 300 sport w/ ford 302 175 hp. low speed idle problems

No that should NOT have messed up your points! When tuning a engine with points ALWAYS set dwell first then set timing. If I remember right 1 degree of dwell changes timing by 2 degree. But timing nor idle speed changes dwell, unless dist. shaft bushing is bad. The sign of a bad dist shaft is when the dwell changes several degree's 6-8 when the RPMs are increased. I had to change the dist in my 351 because of that reason, it wouldn't idle very well. Don't forget try to keep idle under 650 like everyone says, easier on the lower unit. It doesn't have to be dead nuts on 31 degree, 25 may or may not be close enough. I think cars ran 27-31 degree. Have you tried Uraijit's idea of running a seperate tank for test purpose yet? Is your choke opening up all the way? Do you have a wire going to your choke coil ( black plastic round thing )? Take a look at your plugs and see if they are black.

 

[NW Redneck]

Re: timing

Re: timing

Could I have messed up this set of points from all of the adjusting I have been doing? Like touching them w/ the feeler when the key was still on

The points should be ok, but I'm not sure if that could affect the condenser? (this is a NEW set of points and condenser correct?) How do the points look? Any signs of burning or pitting? Did you get any oil or grease on the points from your fingers when installing them, or from a dirty feeler gauge? That can mess up the points real quick. Are the points closing squarely paralell to each other (like this ll not this l\)?

Another thought: you mentioned in your OP that you 'broke the carb down and cleaned it'. Did you check the float level at the time? If it's a little low it could cause it to stall after a couple of minutes.

 

[tacconelli6]

Re: 1977 OMC se 300 sport w/ ford 302 175 hp. low speed idle problems

You get a shock? Maybe it shocked you with enough sense to sell it and get a volvo ha.

Hey JACK! you don't gotta get smart w/ me. Is This supposed to be a help forum for dumb_sses like me? Or a free for all for smart_sses like you?

I see you don't care, but for those that do, I got the timing and the dwell set, I took it out on Lake Pon D'Oreille and had a great time w/ my wife and four boys. She ran good and I was engaging at 600-650 Rpms.

Thank you! to all of you Men who are here to help. Without you, I would be in a real tuff spot. Thanks to you all, I am running my boat before fall and not letting it sit at the marina waiting to be serviced.

If I have any other trouble I will be sure to update or start a new post.

thanks again!

 

[supercab78]

Re: 1977 OMC se 300 sport w/ ford 302 175 hp. low speed idle problems

tacconalli6; glad to hear another stringer drive is alive and running. Do you think it was any one thing keeping it from idleing, or a combonation of things? As aside note I don't know chiefalen but his coment was propably ment as a tonque in check joke. People like to tease us for keeping our stringer drives going, some of them may be previous stringer owners.

 

[tacconelli6]

Re: 1977 OMC se 300 sport w/ ford 302 175 hp. low speed idle problems

I did get worked up pretty quick for no reason, Considering how I handle harrassment my buddies that I know well have been watching me toil w/ this boat.

I believe that cleaning the carb and changing out the filters was neccesary,

Knowing what I know now, I think it started w/ the points going bad and timing getting off. When I broke down on the lake it was firing and I could get it to stay running at higher RPMs but no idle. A guy stopped and helped and he adjusted the point gap w/ his eye and that was it!
I didn't understand the importance of dwell angle or timing until I posted on this site. Dang near Immediately, all of you Men began explaining all of this to me and I learned quickly all of the ingredients an OMC needs to run properly.
Once I set the dwell, got the timing set,adjusted idle speed and checked all of this severel times the boat ran great.
I then went out on the lake and ran at idle and top speed and in between checking the timing and dwell and adjusted the high and low pilots on the carb until it was running strong.
I am now engaging at 580-670. and that is the digital reading variance that I am getting with my meter. So as you know it is right in there at about the 600-650 range that it should be and I am having no problems.
I am glad for this experience as now I have confidence that in the event that something should go wrong I have a good chance of getting to the bottom of it. And with this helpful website, I have the support neccesary to do it myself.

 

[NW Redneck]

Re: 1977 OMC se 300 sport w/ ford 302 175 hp. low speed idle problems

"I am glad for this experience as now I have confidence that in the event that something should go wrong I have a good chance of getting to the bottom of it. And with this helpful website, I have the support neccesary to do it myself."

And that's what this site is all about! The great people here helped me take a long stored, dry siezed, dust gathering relic and turn it into a sweet running
boat that has been bringing our family alot of good times for the past few years. I'm glad to be able to repay the debt by helping others here whenever I can.


'Specially if it's another OMC!

Don't let 'em razz ya. They're just jealous of our 'White (anchor) Power'!!

 

[tacconelli6]

Re: 1977 OMC se 300 sport w/ ford 302 175 hp. low speed idle problems

Hey guys!

I just wanted to log back in and give a report of our little cabin cruiser.

We have had a great summer so far staying out on the boat and she is running great.

We named her HOPE Floats

We are getting ready to go up to Priest river to camp on it over night.

Thanks again to all who helped.

 

[supercab78]

Re: 1977 OMC se 300 sport w/ ford 302 175 hp. low speed idle problems

Wow it almost been a year already!! Glad to hear your getting along fine.

 

[tacconelli6]

Re: 1977 OMC se 300 sport w/ ford 302 175 hp. low speed idle problems

I was out this weekend and my boat started running rough after about 25 min. at near full throttle,

Could my points be bad?

fuel system is good.


What should my rpms be at WOT?

 

[WizeOne]

Re: 1977 OMC se 300 sport w/ ford 302 175 hp. low speed idle problems

What should my rpms be at WOT?

With that 302, around 4400 rpm, give or take.

Sounds to me like you have a fuel delivery problem....but there is always the coil and condensor that could react to heat. If after your troubled run, your points are still properly gapped, they would not be the issue.

 

[supercab78]

Re: 1977 OMC se 300 sport w/ ford 302 175 hp. low speed idle problems

Wouldn't hurt to check the dwell. It may have changed. If you have a anti bleed back valve on the top of your tank just in front of the fuel line the O ring in it may have broken or swelled resticting your fuel supply. My old 75 OMC owners manual said not to exceed 4200 RPM on the outdrive.

 

[tacconelli6]

Re: 1977 OMC se 300 sport w/ ford 302 175 hp. low speed idle problems

Checked the points and they were in bad shape. Appears they welded togather at some point and freed up giving a welt on the contact and a pump on the other.

reset dwell and timing, adjusted the idle mixture a little also and it seemed to be pretty smooth.

Changed points and figured I should change the condenser also. Is this correct?

I need to check the fuel delivery.

WHen I have had this thing running good it will not exceed 3200 rpm. I have checked the rpm with my mutli meter.

I need to figure out why this girl won't get up to that 4200rpm.

Thanks again for your help guys!

ps wiseone, I checked out the sticky for trouble shooting and I think as reccomended I need to thoroughly go through the fuel system.

 

[conk3416]

Re: 1977 OMC se 300 sport w/ ford 302 175 hp. low speed idle problems

IMHO, I believe it would be worth the extra money to change from points to an HEI. I just did it to my boat and it was fairly easy to change and well worth the money. You can get a conversion kit from your local boat dealer. The one i got for my 1973 302 Merc. was about $170 but it is worth it since you will not have to worry about fussing with the pain in the A** Points.

 

[WizeOne]

Re: 1977 OMC se 300 sport w/ ford 302 175 hp. low speed idle problems

IMHO, I believe it would be worth the extra money to change from points to an HEI. I just did it to my boat and it was fairly easy to change and well worth the money. You can get a conversion kit from your local boat dealer. The one i got for my 1973 302 Merc. was about $170 but it is worth it since you will not have to worry about fussing with the pain in the A** Points.

Either that or a Pertronix II ignitor.

 

[supercab78]

Re: 1977 OMC se 300 sport w/ ford 302 175 hp. low speed idle problems

Just in case you don't know. If you leave the ignition key on and the points are closed that can cause the points to pit like that. Of coarse so does time. When mine was running out of fuel it was would die down to idle only, until the carb bowl filled back up. Then it would only plain out for a short time because it would run low of fuel again. I'm not sure you would be able to sustain 3200 RPM if fuel supply was a problem. What pitch is your prop? How big is your boat?

 

[NW Redneck]

Re: 1977 OMC se 300 sport w/ ford 302 175 hp. low speed idle problems

Your WOT should be 3800-4200rpm. The spec page I posted on the first page shows it.

What pitch prop do you have? IIRC mine's a 14X18p and I get around 4100rpm with 4 people and days worth of snacks/drinks etc. My boat is a 18.5' CalGlass V-hull.

 

[WizeOne]

Re: 1977 OMC se 300 sport w/ ford 302 175 hp. low speed idle problems

My prop is a cupped Michigan Wheel 15 x 17 on a 1.50:1 Hydro-Mechanical drive pushing a 19.5' deep Vee. My engine is a bit modified. It is a 5.0 roller cam, w/ a '69 351 Windsor cam grind with roller rockers, GT40P heads, 9.0:1 compression, an Edelbrock 2121 intake and a Holley marine 4160 600 cfm carb.

I've been thinking about going up to a 15 x 19 as I can turn 5k+ with 6 people in the boat. I have never yet held it at wide open throttle. It scares me too much.