1980 9.9 J10RCSE will not idle and dies when you give it throttle.

[Chriswalden]

I have a 1980 9.9 J10RCSE. It idles real rough and eventually shuts down, but if you try to gig I any throttle it will die unless you work the choke. Once up at full throttle its runs out good except for the ocassional miss. I have pulled a compression test with the following results: top cylinder was 125psi and the bottom was 115psi both after three good pulls of the rope. Now I know that Johnson says no more than a 5psi difference but i feel that it should run better than it is with that 10psi difference. I had a weak spark to start, I thought for sure that was my problem. Replaced the plugs, pulled all of my grounds cleaned them and crimped new ends on some of them because the wIre inside some of the terminals was corroded pretty bad. checked all wiring from the throttle plate to power pack and from there to the coil packs. All good. Put everything back together, retested and had excellent spark. Next I turned my attention to the fuel system. I have a fresh mix, brand new fuel line, fittings and filter. Checked my supply to the carb and noticed an inadequate fuel delivery from the pump at Idle. Rebuilt the pump and now have good fuel delivery at any throttle setting. I have no leaks int he fuel lines anywhere that I can see. I then tried adjust out the carb to no avail. No matter what I do it still will not run right. So I pulled the carb and disassembled thinking there had to be a blockage somewhere. The carb is brand new inside. Blew some through all the passages and reassembled. While I had the carb apart I checked to make sure the carb had the proper jet in it as I know the carb kits comes with both the 9.9 and the 15hp jets. It does infact have a 15hp main jet but the carb itself is a 15hp carb wig th bigger throat. So someone put a 15hp carb on this engine. I know that you can do that as there is no difference between the 9.9 and the 15hp besides the carb itself. After reinstalling the carb I noticed that the throttle plate was not contacting the carb butterfly linkage at the marked spot on the throttle plate but I ran out of time. So tomorrow I am going to try adjusting this timing and readjusting the carb to see if I get better results. Any help here is much appreciated as I am running out of ideas here. Thank you in advance.

 

[AlTn]

Re: 1980 9.9 J10RCSE will not idle and dies when you give it throttle.

google..Leeroy's Ramblings...outboard related articles..9.9/15 hp. repair and maintenance...most carb kits don't come with new jets, are you referring to the needle valve seats? More differences in the intake and exhaust area than just the carbs for the 9.9 vs.15. If you'd like to use the search function < and can do so better than I can > you'll see MANY threads on the 9.9 vs. 15 conversions. The area you are heading into with the linknsync should yield major differences in the running . If not, post back, no lack of experienced 9.9/15 owners here. Good luck.

 

[Chriswalden]

Re: 1980 9.9 J10RCSE will not idle and dies when you give it throttle.

Ok, got the carb back on and adjusted the throttle plate cam. Engine runs like a top now, huge difference. I now have to turn my attention to an intermittent water pump issue. I pulled the lower unit off today and found that the impeller and housing are immaculate. I tried shooting water up the copper tube and got water out of the tell tale hole but not a whole lot, what I did notice was that the power head water tube inlet grommet was leaking very bad and allowing most of my water to come right back out the mid section, so I pulled the powerhead for repairs. I also noticed there was a large amount of water coming out of the exhaust manifold. So I pulled the water cover on the head and found that there was no thermostat in the engine, problem number 2. So needless to say I have some parts on order and will post back when I am able to get her in the water for a trial run under a load. It will probably be a while as I have very little time on my hands and very little finances for all the parts I need.

 

[AlTn]

Re: 1980 9.9 J10RCSE will not idle and dies when you give it throttle.

While you're waiting you might enjoy some videos made by bktheking...they are posted on youtube under cpgixxer..something like "9.9 waterpump replacement"..not sure of exact title but he has several vids of his work ..insightful tips concerning making sure you properly align the water tube in relation to the exhaust housing. Probably obvious to you, but you'll probably need a new powerhead to exhaust housing gasket too. Best of luck.

 

[jmendoza]

Re: 1980 9.9 J10RCSE will not idle and dies when you give it throttle.

The water coming out at such a fast rate may not be the upper water tube grommet, it could well be the missing thermostat allowing unlimited water flow back into the exhaust housing, and that would also explain the weak tell tail flow; the system usually has some back pressure and restriction due to the thermostat limiting the water flow. Since it's easy to replace the 'stat, do that first and then do your water flow test again.

If the engine has been run in salt water (this is why people take out the thermostat, so it won't corrode shut because they don't flush the engine) then you need to closely examine the area where the rubber seal of the thermostat seals against the head. If this area gets corroded and pitted, and then the seal will not seal, and the engine will over cool. I had this problem and cured it with a thin aluminum washer (.025") I made from tubing on a lathe, and JB welded it in place on top of the corroded seal seat area in the head. Good luck.

 

[Chriswalden]

Re: 1980 9.9 J10RCSE will not idle and dies when you give it throttle.

Well yes the excessive water coming from my exhaust housing is in fact because the thermostat is missing, but the water tube grommet is also leaking because I can see the water coming out from around the water tube itself when I put water pressure on it.

 

[raczekp1]

Re: 1980 9.9 J10RCSE will not idle and dies when you give it throttle.

at the top of this pipe is small hole, 1.5 mm hole-water will be also flow down,
but its good to instal new gromet

 

[Chriswalden]

Re: 1980 9.9 J10RCSE will not idle and dies when you give it throttle.

I did not know that, I haven't even seen this hole, course I have never really looked at the tube that closely. What is the purpose of this hole?

 

[raczekp1]

Re: 1980 9.9 J10RCSE will not idle and dies when you give it throttle.

to cool down exhoust tube

but lift up powerhead, instal new grommet, also install new termostat

 

[Chriswalden]

Re: 1980 9.9 J10RCSE will not idle and dies when you give it throttle.

I am ordering the parts this weekend and will hopefully have it back together by next weekend. Didn't want everyone to think I was leaving them hanging. The weather here in GA has been really wierd. It's Feb. 1st and was 75*F outside. I wanted to be out fishing but obvisouly have my motor in pieces. Oh well.

 

[Will Bark]

Re: 1980 9.9 J10RCSE will not idle and dies when you give it throttle.

Also, if you are "shooting" water up the tube at full force you are overpowering the cooling circuit and that excess water has to go somewhere and at times it may go places you don't want it to go.

 

[Chriswalden]

Re: 1980 9.9 J10RCSE will not idle and dies when you give it throttle.

Ok finally got everything back together and gave her a sea trail. Dropped it in the river and after a few adjustments to the mixture screw she runs like a top. Still seem to be having some water pump issues. The impeller is fine, the housing is fine. I replaced the water pump housing to input shaft seal as well as the gearcase to input shaft seals. I ended up having to rebuild a portion of the water pump base with JB weld because of some deformation. I filed it as smooth as I could make it. I applied a little bit of high temp silicone in between the water pump base plate and the surface of the gearcase just to keep that little bit of water from coming out. the pump is pumping because I am getting a small amount of tell tale water coming out at WOT. When I got home I hooked it to the muffs and noticed water coming out of the gearcase forward cavity drain hole, which tells me I still have a leak in my water pump. I am going to pull the lower off again and put silicone in between the water pump plate and gearcase, plate and housing and some around the water tube and grommet to see if I can get the water to go up the tube, instead of out all around the water housing. If done carefully I believe I can avoide chunks of silicone from getting into the water system. What do ya'll think?

 

[raczekp1]

Re: 1980 9.9 J10RCSE will not idle and dies when you give it throttle.

starting on mufs, water flows down threw small hole in lower unit(drain hole), located close to lower oils screw,
but when there is to much water in midsection to flow out threw this small hole, water lewel rise up and starts to flow it in any joints between lower unit and midsection.
its my observace

 

[Chriswalden]

Re: 1980 9.9 J10RCSE will not idle and dies when you give it throttle.

So don't silicone anything between the gearcase and the waterpump or plate and water pump? I know that I don't have any blockages, I can pump water into the water tube with the midsection off, with a tool I made, and water flows out the tell tale and the exhaust housing like it is suppose to. The impeller looks brand new, I don't understand.

 

[AlTn]

Re: 1980 9.9 J10RCSE will not idle and dies when you give it throttle.

the hole at the top of the ss cup that lines the inside of the water pump body provides a passage for air to escape as it's displaced by water and this passageway needs to be clear.
Not so sure about the use of silicone to seal the water plate to water cavity lip or the pump body to wear plate. I believe the OMC manual calls for OMC Adhesive M < 3M 847 > between the wearplate and water cavity and nothing between the w/p body and wearplate.
The waterpump body screws are to be dipped in OMC Gasket Sealing Compound before mounting the body.
Coat the inside and lip of the waterpump grommet as well as the bottom of the water tube with a little thin grease as this will help them slide into one another when you install the l/u into the exhaust housing.

 

[Chriswalden]

Re: 1980 9.9 J10RCSE will not idle and dies when you give it throttle.

So I have taken the lower unit back off, and looked at everything real well. I cannot see why this thing is not pumping water right. I put a little water pressure on the water tube after removing the lower unit, and it took very little water pressure from a water hose gun to make water come out the tell tale. I know I have no blockages in that engine. There is something wrong with that pump, its driving me crazy. The little hole for air to escape so that water can displace it is clean and clear. the intake screens are clean. I checked the impeller real good to make sure that the rubber did not disbond from the metal keyed piece, nothing there, it looks like a new impeller. This motor was pumping great and peeing out the tell tale great before one morning I went duck hunting and we came across a few sand bars and a little mud at slow speeds and then when we were headed back in, I noticed the tell tale had nothing but a few drips coming out of it. Any help would be much appreciated.

 

[jrs_diesel]

Re: 1980 9.9 J10RCSE will not idle and dies when you give it throttle.

When I serviced the water pump on my 86 9.9 I had found that my impeller drive key had fallen out and ended up siting in the driveshaft seal area under the water pump. Check and make sure your key did not fall out.

Also, once the thermostat opens up, the flow out the tell tale will be noticeably lower, because most of the water is going through the block and cooling the motor. Mine did that too. Just check the cylinder head area with an infared thermometer, or your fingers. Should be between 140? - 160?, or able to hold your finger for about 3 seconds before it feels too hot to touch.

 

[AlTn]

Re: 1980 9.9 J10RCSE will not idle and dies when you give it throttle.

you may have just had a temporary blockage of the tell tale from the mud/sand...did the motor actually overheat?...a tell tale hose blockage doesn't mean the water isn't circulating in the block or that the pump isn't working...clear the line and you may have to remove the elbow as well to clear behind it

 

[Chriswalden]

Re: 1980 9.9 J10RCSE will not idle and dies when you give it throttle.

No, I don't think the motor actually overheated. It never got real hot, so yall are probably right about the temporary blockage of the tell tale. I put it in a barrel yesterday afternoon and ran it. The tell tale indication is great until the thermostat opens. That was the first time I really got to run it since I put the T-stat in. After it opens most of the water comes out the exhaust and not the tell tale. I now know for sure that the motor is not going to overheat when the tell tale is not flowing that strong. (I monitored the temp the whole time I was running) So thank you gentlemen.