Stuck Carb Throttle Plate - Johnson 9.9

PaxRiver

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Apr 3, 2002
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I have a 2000 Johnson 9.9 Rope Starter motor that got submerged ... didn't find this out for at least a week after being in water. I wasn't able to start the motor once pulled from the boat. The rope pulls fine, pistons move freely. I removed the plugs & sprayed fogging oil through the spark plug holes while pulling the rope starter. Also sprayed fogging oil & lubricant on all external moving parts & linkages. The throttle wouldn't rotate easily and I could see rust & muck in the carb, so I removed the card to clean & rebuild. The throttle plate is frozen solid in the carb barrel. I have not been able to move the linkage or plate even a little. I thoroughly sprayed the throttle plate, shaft, and linkage in carb/fuel injector cleaner, PB Blaster penetrating oil, and PB Blaster lubricant several times over a full day --- still couldn't budge the plate linkage at all. I then soaked the carb in fuel injector cleaner over night and then sprayed penetrating oil, but the throttle linkage assembly still wouldn't move. I could use suggestions -- thanks
 

PaxRiver

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Apr 3, 2002
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Re: Stuck Carb Throttle Plate - Johnson 9.9

I think I messed up. After another night of soaking and using penetrating lubricant I used a wrench on the lever attached to the throttle shaft to try to turn the assembly. I did get the shaft & throttle plate to move, but still not freely. I removed the throttle plate itsef, but no difference. Now the lever moves slightly before the shaft or plate rotate. I must have deformed the connection between the lever & the shaft. The Johnson parts breakdown does not show or list any of the components in the trottle plate assembly, but it appears I should be able to remove the shaft, lever, & spring if I wanted to. Is the whole carb now worthless or is there a way to obtain & replace the throttle plate shaft, etc assembly. Thanks
 

Rick.

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Re: Stuck Carb Throttle Plate - Johnson 9.9

Pax.

I looked at the BRP parts list and I can't see a throttle shaft and plate. Do you have your exact model number handy. I am guessing you will be able to buy any parts you need as 2000 is a pretty recent motor as far a Johnsons go. Have you checked for spark etc.? The reason I ask is you may have multiple problems beside the one your focused on now. Rick.
 

PaxRiver

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Re: Stuck Carb Throttle Plate - Johnson 9.9

Thanks, Johnson carb part # is 0436778. I didn't know how to upload a picture or diagram on this forum. The parts diagram doesn't show the throttle plate, shaft, etc. That's why I don't know if its something I can purchase. I think I can press the shaft out the carb body, but don't know what good this would do if I can't find a replacement or a way to permanently attached the lever/arm onto the shaft. I also don't know if reinstalling the shaft is something I can do without causing a leak.

I haven't checked the spark yet ... suspect I do have multiple problems. Rebuilding the carb seemed an obvious, low cause 1st step no matter what.
 

Rick.

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Re: Stuck Carb Throttle Plate - Johnson 9.9

Pax. Sorry about that, I meant the model number of the engine. If I were you I would take the carb to a Johnson dealer along with your model and serial number. They should be able to help you. I can't find the parts referenced on their website but I'm thinking a dealer may be able to come up with the part numbers. They should be available.
In the FAQ section there is a great link to a fellow who knows a lot about 9.9's. He has one article about what to do if an engine has been submerged. Read it carefully. I believe his name is Leroy Wiesner or something very close to that. I don't know what to advise you to do as I think you could get the carb fixed only to find you have other problems that will, perhaps, prove too costly to restore the motor to working condition. You've done well with the fogging but you should read the article. Rick.
 

R.Johnson

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Sep 24, 2003
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Re: Stuck Carb Throttle Plate - Johnson 9.9

When the carb is built, The screw's holding the throttle plate to the throttle shaft are peened over to prevent them from turning out, and going thru the engine. They were not meant to be taken apart. You would have to buy the upper carb body. You won't find the plate, and shaft by it's self.
 

mikesea

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Re: Stuck Carb Throttle Plate - Johnson 9.9

Did the engine sit underwater for a week?was it fresh or saltwater.From what your describing,I think you might want to consider pulling it apart.As for the carb.shopon ebay or some salvage yards.You will do better to buy a carb,its true about the plate and screws not meant to be removed.I have done it on older engines and was lucky,I used locktite on threads.If you can get the shaft out without bending slightest bit you may be able to free it up.But the slightest bend will bind and you simply cant get it right again.
 

tmcalavy

Rear Admiral
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Aug 29, 2001
Messages
4,005
Re: Stuck Carb Throttle Plate - Johnson 9.9

It's toast if you forced it. Save the old one for parts and start the search for a replacement carb.
 

Rick.

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Re: Stuck Carb Throttle Plate - Johnson 9.9

I sure wish I knew about the screw being peened after installation. I wrecked a 4 hp carb. trying to remove the choke plate last weekend. I have already ordered a used carb off ebay but I was going to remove the choke plate and shaft and put it in my carb. Looks like I should forget about that and just rebuild the one I just bought. Why do I always learn the hard way? Rick.
 

heydanno

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Jun 21, 2012
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Re: Stuck Carb Throttle Plate - Johnson 9.9

I hate to resurrect a 4-year-old thread, but it's the top Google hit for this problem and I wanted to post a more satisfying solution than to buy a new carb. I, too, had a frozen throttle butterfly on my (1990, 2-stroke) Evinrude 9.9 carb. I recently bought the motor and am doing a carb rebuild. Even though the motor wasn't dunked (to my knowledge) the throttle plate was frozen solid and wouldn't budge. I'm happy to say I have successfully freed it up. To anyone else out there with the same issue, my message is: be patient.

I soaked it overnight in Sea Foam. Nothing.
Sprayed PBBlaster, left for several hours. Nothing.
Started to think about putting a wrench or pliers on it, searched, and came to this page (thankfully--really learned from the bad luck of others here)
I figured a little shock would be helpful, so I started tapping with the plastic end of a large screwdriver. In addition to tapping the lever to rotate it, I also tapped on both ends of the shaft. After a whil, I noticed that the shaft was shifting left and right a tiny amount, enough to slide the plate left and right within the carb body. But I still couldn't rotate it. More tapping, and I finally got about 1/16 turn, but with a LOT of effort.
I then moved on to using a small screwdriver inserted through the hole that the cam follower link goes through to rotate it. My thought here was that I'd be able to move it--but still without additional leverage--without finger pain (pushing on that tiny stainless lever really starts to hurt after a while when it doesn't want to move). I gradually got more movement. Kept spraying with PB.
Finally, I used a big plastic spring clamp on the end of the shaft (again, to protect fingers) and rotated the carb back and forth to keep working the movement. Now it's loosened up to the point where the spring even properly returns it to the closed position!

I was sure the shaft was warped or worse but it was just frozen in by corrosion, and it's finally free. So this is a long-winded way of saying a) don't give up hope, b) don't use wrenches or any kind of leverage, and c) be patient. It will come free.
 

RevNick

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Mar 6, 2014
Messages
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Re: Stuck Carb Throttle Plate - Johnson 9.9

I sure wish I knew about the screw being peened after installation. I wrecked a 4 hp carb. trying to remove the choke plate last weekend. I have already ordered a used carb off ebay but I was going to remove the choke plate and shaft and put it in my carb. Looks like I should forget about that and just rebuild the one I just bought. Why do I always learn the hard way? Rick.

I have noticed a lot of people have had trouble getting that carb butterfly out. In fact a friends dinghy sank one night and the 4hp Yamaha went under for about a day. We pickled it and filled it with Marvel and I told him to just wait and I'd come back and get it running for him later. Well one of the old salts in the anchorage knew so much and had so much experience that he went after the frozen butterfly with a small wood chisel and hammer. Needless to say,said carb was ruined. I'm not 60 years old and I don't know everything,but I do know if you strip that carb of all plastic pieces and put it into a toaster oven for a few minutes the cast pot metal will expand quick enough to pop that little butterfly out nice and easy. By the way we had to wait three weeks to get a new replacement carb from Indonesia! Not being cocky,but sometimes those old wise men are just rum talking!
 

nwcove

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May 16, 2011
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Re: Stuck Carb Throttle Plate - Johnson 9.9

welcome to iboats rev! confucius says: he who replies to a 6 year old thread with a big red banner saying not to, should not knock old wise men!!
 
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