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89 15hp stalls when I attempt to throttle

C

Cjalbert

Member
Hi All,

The motor purrs at idle @ 600-700 RPM, but even in neutral I will quickly bring up the Idle arm for on the remote control and it will ramp up to 2400 then bogs itself all the way down until it stalls, If I push the throttle arm on the remote controls down it will catch itself and begin to idle perfectly again, but if I let it bog all the way down to stall it takes a few more revolutions of the starter to get it going again. but then it will run at idle perfectly,

Just before I did everything listed below I had it on the lake and had it doing the same thing in gear, but after 25 times or so I could get it to "catch" and run almost 4200 RPM (prop was too big/got a smaller one) then when I stopped it would naturally stall and not want to start.....thats when I discovered that the brand new cam roller cover was cracked and half broke off, I thought that the new one would remedy this but no luck?

Timing? Any suggestions?

I have already done,
1)Complete carb rebuild.
2)replaced the cracked carburetor cover...new kit
3)Carb cam roller
4)Fuel pump rebuild.
5)Test all lines and replace zip ties with band clamps
 
Sound like a fuel restriction issue,fuel pickup tube in tank checked? fuel primer bulb working properly? Fuel pressure been tested? Have you tried squeezing primer bulb constantly
 
Do a cylinder drop test while ideling. Pull a plug wire and quickly put it back on. The engine should respond the same on both cylinders. When you rebuild a carb be sure and replace the fuel lines possible chunk of crap got in from the old fuel lines. Maybe clean the carb again and replace the fuel lines and see if it cures the problem? Be sure and pull the high speed jet and clean it with a copper wire.
 
Hi Guys,

I did the drop cylinder test after replacing the plugs and wires, good, I didn't have a compression tester I hope to have one tomorrow, this weekend was a wash....thanks for the suggestions. I will report back with findings
 
Also make sure the carb throttle linkage is touching the timing cam when you advance the throttle. . . .


CMOS
 
Question for you Cjalbert: How did you adjust the float up and down travel when you rebuilt the carb?
I am asking because I went through the same routine recently and had the exact same issue you describe when the motor stalls after a full throttle run, and I believe the float adjustment is my problem.
All I could find online (and on the manual) is "make sure the float is parallel to the carb body surface".... but that, in my opinion, is not enough to adjust when the needle is supposed to open and shut the fuel flow.
 
Hi Jupiter,

I am also skeptical about the carb adjustment and I had actually played with it quite a bit I also only had the manual which didnt help me much the 1-3/8" drop is useless as the bowl holds the float much higher than that. I had actually bent the tang a little up? I thought I might be flooding out because the float valve wasnt closing. I will go back and try opening it up a bit. I would think though that if there is fuel in the bowl then it would get up and go and then die out....not die out due to lack of fuel.(just re-read your post) you were saying after a run it didnt want to start-OK were you having any issues with the 1400-1600 hurdle were it didnt want to go past? Or just the stall after full throttle run?
 
Cjalbert said:
you were saying after a run it didnt want to start-OK were you having any issues with the 1400-1600 hurdle were it didnt want to go past? Or just the stall after full throttle run?
Click to expand...

Just stall after full throttle run only.
I can troll at idle/slow speed all day long without any issue.
It goes great and fast at full throttle too mind you, but only for a certain amount of time until it starts with erratic reving and eventually stalls after I turn the throttle down.
Getting ready to pull the carb again but I came fishing for info online first, as I really would like to know what to do with respect to the float travel adjustment, so I don't have to get in the carb a fourth time, after this one! :)
 
Jupiter Dinghy said:
Question for you Cjalbert: How did you adjust the float up and down travel when you rebuilt the carb?
I am asking because I went through the same routine recently and had the exact same issue you describe when the motor stalls after a full throttle run, and I believe the float adjustment is my problem.
All I could find online (and on the manual) is "make sure the float is parallel to the carb body surface".... but that, in my opinion, is not enough to adjust when the needle is supposed to open and shut the fuel flow.
Click to expand...

I see your point, but it is enough. With the carb upsidedown the needle is closed, right? With that needle in the closed position the float should be parallel to, or 1-2 degrees up from, the carb body (Joe Reeves method). Not sure why you feel this adjustment isn't "enough" - ?

CMOS
 
Cmos,

That was exactly what I finally did, flipped the carb over and blew into the gas line, then attached the bowl and did it again, it still was not easy...but I thought the fuel pump is constantly trying to push fuel at it so It should be enough to fill the bowl.

Unfortunately I could not get to the compression test yesterday...hopefully tonight. Thanks again
 
All I do is turn the carburetor upside down and make sure that float is level / parallel.----Never any problems that way.-----Most carburetor " problems " turn out to be something else !
 
Hey All, I had about 5 Min to test the compression last night, not sure if I was supposed to keep the gauge on it for a specific time after but it reached a little over 105 psi in both cylinders, and I think that the fuel system is working well up to the carb.....I think I am going to take it out again and as suggested and make sure the high speed jet is clean?? any more suggestions?
 
OK folks, I am starting to get REALLY frustrated.... I did all the above mentioned before putting the carb back in, even did the blow thru intake port and moved the float up and down to make sure air was going thru then shut off, and guess what? now the motor won't start. LOL!!!!!
Third time in a row that this happens to me.
Now to set the background, I want to say that I am not a complete stranger to 2 stroke motors, I have rebuilt and maintained quite a few dirt bikes/mopeds in my younger days, but I am getting stuck here. This was the best running 9.9 motor I ever had, now it won't start.
My first thought was: Is there something I have to watch as far as the linkage between carb roller and the timing plate? Maybe this got thrown off?
I just gave up for a breather right now, guess I'll start from scratch with a spark test and go from there, but if anyone has suggestions, I'll be eternally grateful. :)
 
I surmise that your engine (in the water) idles fine, and would idle all day if you desired, and will still continue to idle even when in gear... BUT... when you attempt to advance the throttle, the engine wants to fall on its face so to speak. If so..............

When cleaning the carburetor, did you actually manually and carefully clean the high speed jet with a piece of single strand steel wire... if not, do so as your explanation indicates that the HS jet is somewhat fouled.

If you had a fuel restriction between the fuel pump and the fuel supply, the fuel primer bulb would have a tendency to be drawn flat... and you don't mention that.

If I am in error about your engine's present problem... give me a brief explanation of what it is, or is not doing.
 
Racerone: Yes the choke vane does close correctly.
Joe: Just a little correction to your summary: Yes, it idles beautiful and can do this all day long, but when I do open the throttle wide, it catapults the boat like the healthiest 9.9 hp you will ever encounter. And keeps going fast for a while, then as I roll the throttle back, this is when it wants to fall on its face. And does, most of the time, meaning it stalls, unless I am able to keep it running by quickly doing some opening/closing with the throttle, when I'm lucky. Note that after the stall, I never had any issue starting it back up...
And yes I did thoroughly clean the high speed jet, went in there with a piece of metal wire snatched from a brush, sprayed with carb cleaner, and blew air in it. I could see through the wide open and clean orifice after these steps.
Fuel pump: No restriction there (the pump is not 3 months old, as I put a new one, along with new fuel lines and the initial carb rebuild, when I put the motor back in service after years of storage)

Thanks to both.
 
BTW Cjalbert: Thanks for hosting my thread within yours! lol (apologies for the hijacking... but I guess since we're talking about similar motors, all info gathered can benefit both?) :)
 
No prob Here Jupiter, just very grateful we have really cool people that are willing to impart their knowledge, btw just cleaned out the carb again and it would seem the high speed jet was a bit cloged -about to attempt to fire it up again and see what happens, one more thank you to Race -Joe and Cmos - I will report back with the results
 
Jupiter Dinghy said:
Joe, Just a little correction to your summary:
1 -Yes, it idles beautiful and can do this all day long.
2 - When I do open the throttle wide, it catapults the boat like the healthiest 9.9 hp you will ever encounter and keeps going fast for a while.
3 - Then as I roll the throttle back, this is when it wants to fall on its face. Most of the time it stalls.
4 - I am able to keep it running (sometimes) by quickly doing opening/closing the throttle.
5 - I never had any issue starting it back up.... I did thoroughly clean the high speed jet.... New Fuel pump.... I put the motor back in service after years of storage.
Click to expand...

1 - Great for trolling.
2 - The terminology "catapults" is used..... If the throttle is advanced slowly, does the engine increase its rpms gradually or does it hit a spot whereas the rpms jump up to an extreme?.... You say... keeps going fast "for a while"..... What happens at that "while" point?
3 - Are you reducing the throttle gradually... or dropping from a high rpm to near idle in one quick stroke?
4 - That is very strange as most outboard carburetors (yours) do not have a internal auxiliary fuel pump... opening and closing the throttle does nothing more than move the throttle butterfly back and forth Open/close.
5 - You've pretty well covered all the bases there.

The fact that you have no problem restarting the engine indicates that fuel is still present in the fuel pump, carburetor and fuel lines, unless it's necessary to pump up the fuel primer bulb again to fill the carburetor. Let us know.

If the rpms drop drastically at one point when slowly and smoothly reducing the rpms, I would suspect that possibly the timer base (armature plate) under the flywheel is sticking and suddenly retarding to where it belongs as the throttle is moved a fraction more... OR... the throttle linkage governing the throttle butterfly is worn or out of adjustment, allowing the butterfly to move a great amount at one point.

There is a scribe mark on the cam that slides against the throttle roller. The butterfly should just start to open when that scribe mark is dead center with the roller.

With the engine NOT running but in gear, observe the throttle butterfly to see if it moves smoothly closed to open to closed as the throttle is slowly open and closed... OR... if it suddenly moves/jumps a distance at one point.
 
joereeves said:
OR... the throttle linkage governing the throttle butterfly is worn or out of adjustment, allowing the butterfly to move a great amount at one point
Click to expand...

Hi Joe, here I am with an update, and it seems the little quote up there, was the root cause of my issue (hopefully).
The plastic roller which is in contact with the timing plate was completely worn on one side, to the point where the plate dug into the plastic.
Since I felt this might be where my problem was, here is what I did, that finally got it started: I disconnected the linkage completely, and hit the start button (thanks to the electric start) while opening the butterfly wide, and it started. I ran it a couple minutes, operating the butterfly manually, and then replaced the linkage with a brand new looking roller that I had on part motor, (oh and I aslo made sure the slow speed needle was 1.5 turn loosened from the bottom and it seems to be right where it wants to be for a smooth idle).

Now I won't know for sure if my stalling issue after a full throttle run is fixed until next weekend when I can get the boat in the water, but right now it sounds really good, with a much better throttle response and smooth idling, so color me optimistic, and I will let you (and everyone else) know how the ride went....

Thanks again a million, and you once again seem to have hit the nail right on the head with the worn roller suggestion!

Now I really wonder what I would have done with a manual start motor....! :(
 
Last edited:
Hi Jupiter,

I had actually had a brand new idler roller break on me and was able to cut 2 small pieces of 1/2" pex- and slice it lengthwise and glue it back together for almost exactly the same diameter maybe a 1/32 off. And this one should break so easy.

My problem was the High speed jet clogged, and I had her up to about 5300 rpm!!!!!



Unfortunately I am now still dealing with what looks like either another leak after all of hose clamps and going through the fuel system, I still have a sheen develop on the water behind me after running a while. It does dissipate, but bothers me..... wondering if it could be to rich, the book stated low speed idle to be 2-1/2 turns out but I have it at 2 now and I will be trying to get it back to 1-1/2 as that's what I recall being the right setting?? Too many beers and different motors.....Thanks again guys you keep me sane or at least keep me from being completely out of my mind with these small motor issues.
 
Hi Jupiter,

I had actually had a brand new idler roller break on me and was able to cut 2 small pieces of 1/2" pex- and slice it lengthwise and glue it back together for almost exactly the same diameter maybe a 1/32 off. And this one should break so easy.

My problem was the High speed jet clogged, and I had her up to about 5300 rpm!!!!!



Unfortunately I am now still dealing with what looks like either another leak after all of hose clamps and going through the fuel system, I still have a sheen develop on the water behind me after running a while. It does dissipate, but bothers me..... wondering if it could be to rich, the book stated low speed idle to be 2-1/2 turns out but I have it at 2 now and I will be trying to get it back to 1-1/2 as that's what I recall being the right setting?? Too many beers and different motors.....Thanks again guys you keep me sane or at least keep me from being completely out of my mind with these small motor issues.
 
Cjalbert said:
Hi Jupiter,
Unfortunately I am now still dealing with what looks like either another leak after all of hose clamps and going through the fuel system, I still have a sheen develop on the water behind me after running a while. It does dissipate, but bothers me..... wondering if it could be to rich, the book stated low speed idle to be 2-1/2 turns out but I have it at 2 now and I will be trying to get it back to 1-1/2 as that's what I recall being the right setting?? Too many beers and different motors.....Thanks again guys you keep me sane or at least keep me from being completely out of my mind with these small motor issues.
Click to expand...

Ah!.... those motors always find a way to keep you busy somehow, don't they? lol
But I still love them. When they're tuned fine, the new ones have nothing on them....

As far as the low speed needle adjustment, my manual says 1.1/2 turn out from bottom, maybe it went to 2.1/2 with later years?....
Looks like you're down to the fine tuning now.... light at the end of the tunnel! Good luck!
 
Cjalbert .... The following may come in handy.

(Carburetor Adjustment - Single S/S Adjustable Needle Valve)
(J. Reeves)

Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.

Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.

Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.
 
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