Force 50 hp, hard to start cold although timed and synced properly

ZandoR

Seaman
Joined
Sep 5, 2016
Messages
57
Allright then:
I performed the carb adjustment without having any luck. At some point I noticed a bit of gas sprinkling from the top left of the carb, seems like there is the welch plug missing (One of those small golden ones).
Those bolts on the dog bone sgaped cover a pain to get to. Will try to get myself a socket that fits to get them out tomorrow.
What I found interesting is, that when I restarted it hot it would idle just fine for about 5 seconds and then go back to the miss. Could it have something to do with the lack of backpressure on the exhaust? While throttleing up it sounds ok to me, but up until 1300 ish rpms it doesnt stop missing when left at a certain rpm.

Loooking forward to your advice and have a great day,
Leo
 

jerryjerry05

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There should be 2 plugs on the top of the older style carb.
You say the little one is missing?
​Post a few close up pics of the carb and where it's missing a plug??
 

ZandoR

Seaman
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Sep 5, 2016
Messages
57
Ok I got to it again today. Indeed there was some varnish in the screens (looked like shrapnel or shavings of smth).
The reeds were still intact. Started her up afterward and she would have the same symptoms. Out of curiosity I richened up
the mixture by winding it out about a turn. It then stopped missing eventually. I believe to be out about 2 - 2,5 turns which seems to be way to rich. Am I having a vacuum leek somewhere?
After running for 10 secs it shot out a little bit of fuel out of the carb as mentioned earlier, but never did again afterwards. There should be a picture attached to it. The carb is from a 70 hp but looks exactly like mine (except the metal cover on the intake side. Is it supposed to be that way?

--> Hmm, the attachment button doesnt work, so heres a link to the picture Im refering to:
http://vintageboatparts.com/parts/z_store/8/carbs/050.jpg

The opening im talking about is located in between the mixture adjustment screw and the opening filled with that red stuff.

Best regards,
Leo
 
Last edited:

jerryjerry05

Supreme Mariner
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The "red stuff" it's usually called "Indian Shellac"
It's a gas/oil impervious sealer that seals the welch plugs.

​You could be missing a plug?

Usually the air screw starts at 1 and 1/2 for initial adjustment.
Then can either go in 1 turn or out a turn.
Usually turning it in is what's needed.
​Try starting the motor and spraying starting fluid around the intake area.
And all around the motor.
If that makes it run different then you probably have an air leak?

​When adjusting the air screw: you need to turn it in 1/8th increments and wait 10 seconds between turns.
​That burns the fuel/air at the old setting and gives it time to see if it likes the new setting.
 

ZandoR

Seaman
Joined
Sep 5, 2016
Messages
57
Allright, Ill be on the water in two days
​I will perform all the Tests then and Keep you posted.
Im stoked to see how it performs.

Happy Boating,

Leo
 

ZandoR

Seaman
Joined
Sep 5, 2016
Messages
57
Ok I got it out in the water. The carb spitting some gas was actually caused by the float being stuck in the open position.
After setting the idle to a normal speed i tried to shift in gear. tried reverse first which worked fine. Then tried to go into forward.
Felt it engaging for a sec and then the rpm just shot up. The problem was that the threaded rod coming from the recirculation
system cover (dogbone shaped) broke right of where shifter was sitting. Will try to get some pics of it online here in the next
couple days. The boating season for this year is over now and the boat has been taken out of the water, so im not in a hurry to
fix it. Unfortunately there is a whole lot of other stuff comming up in the next few weeks so I wont be able to be on here as frequent.

Appreciate your thoughts about how to fix this issue!

Have a nice day,
Leo
 

jerryjerry05

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Post the pics and add the rest of the model#
The recirc system changed sometime during the 92-94 era.
Depending on the EO model#??
 

ZandoR

Seaman
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Sep 5, 2016
Messages
57
Ok heres a little update:
In the past month I wasnt able to get to motor at all. As we have hollidays right now I will be taking of the recirc cover to get a better impression on how it could be fixed. Youll get the pics either the upcoming or the weekend after. Sorry for letting you all wait that long though. Hopefully she?ll be all fixed up when the new season starts :).

Enjoy your day, Leo
 

jerryjerry05

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Enjoy the holiday!! Were heading into winter here and the snowbirds come back and make life interesting and exasperating!!
​Snowbird: an elderly person who can set through 2 traffic light changes without noticing the light has changed.
 

ZandoR

Seaman
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Sep 5, 2016
Messages
57
Thanks Jerry,
I sure did. Here You have the pictures as promised. I wonder if I could just Dremel a Slot for a straight scredriver bit into the stud. I have a bit for a 1/2 ratchet that would be rigid enough to break it loose. I Still wonder how it was even possible for it to break as it was right behind the nut. Well, I guess the idle was a little high.
 

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jerryjerry05

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The stud looks like it's a press in type???
​With the right amount of heat and ice you might be able to get it out??
​The parts soft aluminum and can melt so be careful if you use an acetylene torch.
​Heat it as hot as you can get it then touch the top of the stud with an ice cube and immediately try to pull it with pliers or vice grips.

​On e-bay they have one. 262703866045 $37 US They might ship overseas???
 

ZandoR

Seaman
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Sep 5, 2016
Messages
57
Hm that sounds a like its hard for me to do without a torch. I was thinking about drilling through and then cutting threads for an M10 which would be the metric equivalant for the size stud that is in there. Even if would get get the stud out I wouldnt know where to get a new one to stick in there so it might be my only option for being cost effective. What do you think?
 

jerryjerry05

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Yes that could work.
You should be able to get a stud from an auto parts store.
Maybe take it to a machine shop?
​Good luck, let us know how it works?
 

ZandoR

Seaman
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Sep 5, 2016
Messages
57
Ok will do. Five big exams comming up in the next month so it might take me a few weeks to get her done.
​Ill do a few phone calls to find out if anybody knows the fitment tolerances for american build engines.
Maybe I can then modify a metric stud to fit?

Best Regards,
Leo
 

ZandoR

Seaman
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Sep 5, 2016
Messages
57
Happy New Year everybody!

Heres a little update on where I am at right now:

I drilled out the old stud using a 10,5mm drillbit. Will cut the threads to an M12 later. Im just wondering if there is enough meat on the shifting lever once its drilled to 12mm. Unfortunately the engine is sitting some place else and Im not too sure when I can check. A possible solution might be a helicoil then I guess. My thoughts were to screw the new stud in with a dab of epoxy. Theres no need to have it apart again anways.
I also have one other issue that I forgot to mention last year, and that i cant find anything about. When I go wide open on the controls it opens the butterfy way to far, so that it closes again. Also the distance between shifting and giving it some gas is really narrow.

I am looking forward to hear what you think about my ideas!

Best wishes Leo
 

jerryjerry05

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There should be enough unless the new is too big.
Yes add the epoxy.
Sounds like the cables need adjusting.
Do the linc and sinc in one of the top posts.

How'd you do on the exams??
 

ZandoR

Seaman
Joined
Sep 5, 2016
Messages
57
Thanks Jerry!

Ill see if i can get it done in the upcoming week. I will add some pictures then. Exams went really well for me, actually it was my best semester so far :).
As far as I know the engine itself is synced properly. I adjusted the throttle cable to be at idle without any slag with the controls in the neutral position.
To me it kinda looks like the controls draw in to much cable which is weird cause they are the originals that came with the motor. Is there a way of adjusting them?
 

jerryjerry05

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Without looking at the shifter??
​It's possible the cable is in the wrong position on the shift arm??
 

ZandoR

Seaman
Joined
Sep 5, 2016
Messages
57
Ok heres a little update:
​I measured the hole diameter of the shift arm. Its pretty much 12,5 mm, so If I go with an M12 it should fit well. The bypass cover is off to a friend of my uncle who is a machinist (turned out to be problem for me to cut the thread with my tools). Regarding the throttle linkage issue I will have to wait for the spring to crank the weather up a bit more. When giving it a deeper thought I started to wonder if there is a broken throttle stop, as there was one on all OMC engines I had so far. Maybe someone has an idea?

Happy boating,
Leo
 

jerryjerry05

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There really shouldn't be a throttle stop?? Pics of the linkage?
​The shift levers should just reach the end of their travel.
What shifter do you have?
Pics of yur setup??
 
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