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81 j150 engine problems

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josephrivera

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"A while back i took my boat o

"A while back i took my boat out to a lake and i was having problems firing up, sounded a little like the engine was flooded. Someone suggested i clean out the carbs, i did, i took it back out and it fired up, but when i pushed the throttle, it stalled out. I took it home and hooked it up to the hose and it fired up, but to about 7500 RPM, and shut off a few seconds later, and it keeps doing the same thing. I figure it might need an adjustment on the throttle cable to lower the start up RMPs, but i dont know what would cause it to shut off after a few seconds. All the major compenents like the starter, the fuel pump, and the solenoid have been replaced. Im out of ideas. Please help"
 
"I sure hope you are not runni

"I sure hope you are not running that engine at 7500 rpm. I can only assume that you mean 750 rpm at idle on the hose, and then after a few secs it cuts off. Is that right?"
 
"No no, it would go to close t

"No no, it would go to close to 7500 RPM. I dont know why, it has always started up at about 5000 RPM, dont know why the sudden change. Like it would start, slowly get up to normal RPM then shoot up to 7500, then dies off."
 
welcome to marineengine!!

i

welcome to marineengine!!

i too hope you are reading the tach wrong.

that motor should be wound so tight it is about to explode..........literally!!!

your max rpms are 5500........it should idle at 600-800 .....depending on preference.

its not even advisable to hit 5000 without a load on the eng.

idont see how it could go that high unless you have it in gear......your fast idle lever shouldnt even make it go that high.

not to mention most tachs only read 7500....marine tachs anyways.

are you sure about the rpms?.....im not trying to be an a****** .....just confused about those rpms.
 
You are aware that 7500 rpm is

You are aware that 7500 rpm is way above the redline point for 'Rude outboards...way over.
It must be screaming! Don't run it like that.

I re-read your post....you just have to be reading the tach wrong. No engine when running right starts up at 5000 rpm. You gotta be reading the tach wrong.
 
"On the tach dial, starting fr

"On the tach dial, starting from the farthest counterclockwise position of the needle, the zero position, the very first large "1" you come to on the dial is 1000 rpm. The next "2" you come to, is 2000 rpm. 7500 rpm will be all the way clockwise pegged against the far clockwise stop of the tach.

You gotta be reading it wrong."
 
"The only way this might happe

"The only way this might happen is if the link between trigger and throttle arm is gone, and the timing goes to max advance. On top of that the carbs must be flooding fuel."
 
Even at full advance and no th

Even at full advance and no throttle it wouldnt get to 7500rpms Does the motor sound like it is really screaming if it is you have some investigative work to do.
Check that the carby butterflys are opening and closing...check the timing with a timing light and post what you find
 
"Oops, sorry it was 5500, not

"Oops, sorry it was 5500, not 7500, you'll have to excuse me, im half retarded. But i may have fixed that. I just adjusted the cable that attaches the throttle to the carbs and it is now firing up at 1500 RPM, but it continues to just die after a second or two."
 
even using the choke?

does

even using the choke?

does the primer bulb pump up hard?

does the bulb go flat?...it will soften some when you start it.

did you change anything with the synchronization?....the carb cam shouldnt be touching the plastic roller at all at idle.

does the timer base move all teh way back and forth or does it stick?...your control should have a idle adjustment screw that it rests against.

1500 is still a lil high.

are you using muffs or a barrel?
 
"Well i have to have it at ful

"Well i have to have it at full choke to start it cold.
The bulb does harden, it couldnt, or i hope, be a problem with the fuel line, ive replaced the bulb the filter and the the pump recently. It act normal.
The synchronization should be fine, i havent screwed with it.
Now the timer base has gone a little awry. It goes back and forth but barely, theres not much tension between it and the choke.
It has always strated up around 1500, doesnt get there, but gets close, may need just a little more adjustment, and that may have something to do with the throttle cable."
 
yes you will have to give it f

yes you will have to give it full choke....and then maybe choke it a little to keep it running til it warms enough to stay running
 
"I am sorry...I just don't

"I am sorry...I just don't get what's going on here.
5500, 7500, now 1500...
Good luck to you.

I recommend taking it to a qualified dealer."
 
"doug, i think hes saying he m

"doug, i think hes saying he misread the tach AND had the throttle cable waaaaay to tight."
 
"Who knows...
He is talking a

"Who knows...
He is talking about the timer base being connected to the choke, and being too tight.
Now come on...no choke on that model, primer solenoid.
He has to give you good understandable info. Call me too harsh...or an ass...e, but I can't follow it.

Are you gonna stay with it David?"
 
"Ok i think im confusing every

"Ok i think im confusing everyone, im no mechanic so bear with me. There is a choke on this motor.

Now, as simple as i can say, when i take the boat to the lake, it starts up fine, but stalls out when i try to open it up.

When i take it home and hook it up to the hose, it starts up at an abnormally high RPM, and dies soon after. The primer bulb, the fuel filter and the fuel pump are brand new. The starter has been rebuilt, the solenoid is also new, as are the spark plugs and wires. What would cause it start at such high RPM's (4000-5000 (no BS)) and die seconds later, and what would cause it to stall out? And how would i fix this?"
 
"OK...sorry I got frustrated.

"OK...sorry I got frustrated.
If your motor is as it came from the factory, you have no choke.
You have a primer solenoid which is activated by pushing the key in. We sometimes use "choke", but it really is a solenoid that enriches the fuel when cold starting. It has no choke butterflies in the carbs. That is just us being loose with the terminology.

The butterflies in the carbs are your throttle butterflies. They are connected together, all 6 of 'em, and are controlled by that large lever on the starboard side that the throttle cable connects to at the bottom. They all work together, and must work exactly together to be correct.
Now, I am afraid of what you are doing. It seems as if you are changing adjustments on the engine. These engines are very sensitive to all the adjustments, because everything is mechanical. By that I mean that the carburetor opening is closely synchronized to the timing advance through a mechanical linkage. no electronic timing adjustment....it is all mechanical. (Speaking in general, you experts, in general).
This is called "link and sync". It must be done right. No guessing here, because you will run the engine with the wrong timing, and could blow it up.
Upon starting the engine, if it races up to 5000 rpm, that is absolutely incorrect. Do you have the fast idle lever raised? That may do it, but you should not really have to race it up that high.
Somebody post him the correct starting procedure...

So, I will offer up a piece of advice. If you are gonna do this work yourself, get yourself a FACTORY SERVICE MANUAL. Not a Clymer, not a Seloc. An OMC factory manual. And read it very carefully. It will tell you how to do the link and sync, and how to correctly adjust the throttle cable and shift cable coming from up front.
It won't help you get it fixed tonight....but you will be better off with it.

Mort may have touched on the issue...the linkage between the throttle and the timer base may be way off...

I just don't know at this point."
 
"doug,
well he needs help....

"doug,
well he needs help....i just dont know if i skilled enough to help.

joseph,
i thought you solved the wide open at start up problem.

have you messed with any of the linkages other than the throttle cable?

do you have a manual?....its a must if you are going to be doing the work yourself.



sounds like you have some linkages adjusted wrong, missing, or disconnected....you have to have advanced timing for it to reach full rpms..........and fuel on top of that..like morten said above......... i think morten nailed it before...

can you post some pics of your linkages....the ones that go to the timer base, etc...?"
 
"hey........i have to hunt and

"hey........i have to hunt and peck.....looks like we are both thinking ------ timer base.

to start your eng you should :

hook up soem muffs or put eng in tank of water

open the vent on the fuel tank, if you have a tank with a closeable vent...got it this time vic

pump the primer bulb til firm

raise the fast idle lever

push in key and turn

after it starts you may have to lower the fast idle lever some to keep it from over revving

you may also have to punch the key a few times when its cold in order to keep it running.
.....................................................
hope i didnt leave anything out......oh yeah put it in gear-- open a beer ---and accelerate."
 
"I think, in reading and re-re

"I think, in reading and re-reading, that he raises the fast idle lever all the way up. He then pumps the primer, and pushes the key in while starting (I will avoid the use of the choke word). When it fires, it races up to 5k and then runs out of the gas that was supplied on the initial primer shot.

If this is the way it is, try this.
Don't raise the fast idle lever up past 1/3 of the way. Do your normal starting procedure, pump the bulb, etc., and when it starts, press the key in again. Keep pressing that key in to see if you can make it run thataway. That will hopefully shoot more gas in, and may keep the engine running. It should not race up near as high as 5k.

Post back what you find doing this procedure."
 
"if hes running out of gas he

"if hes running out of gas he has some fuel issues.......but we can address those issues after we help him stop it from over revving at start up.

hopefully you idea about the fast idle lever will help.......he may need to just unhook the throttle cable and see if that helps....may make it a lil harder to start withouit advanced timing but it may eliminate the adjustment problems.

hopefully we will have some pics soon.

p.s. joseph, i use photobucket.com its free and easy or i couldnt do it ----- i do good to wrok the computer sometimes lol."
 
"ok great we're on the sam

"ok great we're on the same page. When i was thinking "choke" i was thinking the fast idle lever which is connected to the butterflies (opens them) on the carbs, so i thought it was the choke. But yeah i have to press in the key, i understand now.

Now, tried starting it with the idle lever at about 1/2 and it did start up at lower RPMs, around 2500. after it started i tried pushing in the key to keep it running while lowering the lever, but it still died. Now refering to it possibly flooding, the last time i cleaned the carbs, i opened the casing and an unusually large amount of fuel poured out, so theres a problem there. That may have been an important part.

Now, knowing that it still dies, might i have a bad plug?? I figure that if only one or two were bad it would still run, just not very fast, this has happened in the past. It better not be a fuel line problem, ive already spent a ton of money on it. Now ill have pics up in a bit."
 
"NOPE dont worry about plugs y

"NOPE dont worry about plugs yet.
It starts and revs to around 2500, then dies.
OK, try this. Two ppl. Start it just like you did before, exactly, but have someone pump the primer bulb after it starts. Try to keep it running with the primer bulb.
Let us know what happens."
 
"Joseph,
All good advice here

"Joseph,
All good advice here,BUT you need to slow down,get and study the manual,and work through this systematically."
 
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Greg, im just trying to narrow the problem so when i go to the manual, i know what im looking for, i dont wanna spend hours on fixing the wrong thing. And my damn manual got caught in the rain, all sorts of screwed up, so i have one on order at a dealership. Hope these pictures are helpful"
 
"Joseph, can we have bigger pi

"Joseph, can we have bigger pics, particularly the second one,showing under flywheel to confirm timer linkage"
 
on your pics the part we are i

on your pics the part we are interested in are cut off.

the lever your throttle cable is connected to should have a lil rod connecting to the timer base under the flywheel.......cant see if it isthere in your pics.....but you can tell us if it has one there....just above the yellow sticker
 
What happened when you pumped

What happened when you pumped the primer to try to keep it running? Have you done that yet?
I am concerned about fuel delivery.
 
"Doug, It did help a little, s

"Doug, It did help a little, stayed on for a few more seconds, the bulb continues to stay relatively firm, it goes soft only for a little bit. Sounds a little odd, unless thats whats supposed to happen. However it wasnt on long enough to charge the battery and it dipped a little under 12 volts, so i have it recharging now."
 
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