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1987 Evinrude 9.9hp

Jupiter Dinghy

Jupiter Dinghy

Regular Contributor
I just fell on this 87 motor, I thought I'd give it a shot to see what kinda progress OMC accomplished between 79 (the most "recent" 9.9 I've owned so far) and 87.
After replacing lower unit/impeller, recoil starter, and unclogging an obstruction in the water circulation, I got it to run, and pretty good too.

1st question: I checked the temp with an infrared gun at the head, and I noticed that the bottom cylinder is running hotter than the top one (between 140 & 145) while the top one measures around 105..... is that typical? Or a cause for concern?

2nd question: On my 70's puppies, there is a certain amount of throttle that you can (and must) open to start up, which is limited by the gear selector mechanism that stops the rotating plate just as the throttle opens up, and to prevent engine damage by revving up too much in neutral.
Well on this 87, there is NO throttle opening at all. It starts fine without any throttle mind you, and the throttle does engage all the way in forward and reverse, but I was surprised that there is no way to throttle it up at all in neutral, unless you manually open the throttle by pushing the linkage with a finger.
Is this a factory setting? Or a cause for concern? :)

Thanks.
 
kevinj said:
Is part #1 missing on your throttle linkage?
http://www.marineengine.com/parts/j...ection=Steering+Handle+&+Throttle+Control

I replaced the starter rope on my '79 9.9 and didn't get the pawl oriented properly. With it in the wrong position I was able to pull start the engine while in gear. Would that have the same effect you've observed?

KJ
Click to expand...

Ah! you might be onto something here...... the thing is I replaced the recoil starter with one from an OLDER motor without the little leg on the side where this pawl gets settled against. Since it was serving the function fine (turning the motor) I didn't think it would hurt any to just stick the red pawl behind it, but if its purpose has anything to do with allowing the throttle opening in neutral, then that is why it's gone.

(I never really understood what the purpose of this red pawl was to be honest, I also have it on my 79...)

Thanks for the heads up, I guess I will look it up closer and try to understand this thing....

Push comes to shove I will try repairing the original recoil which has the spring uncoiled (I didn't feel like messing with it yesterday) :)
 
The arm that locks the recoil is based on throttle position. When in neutral, you can barely give it enough throttle to start. The factory setting is engineered and has to be adjusted with unconventional means. I have made these mods on my 87's up at my resort in Canada. With a little more throttle ability in neutral, it minimizes how many times the operator has to pull it in cold start circumstances. My motors still have the original starter cords with thousands of hours on them. The engineers should have added a tweak more throttle for starting. All my 87's were purchased brand new and the problem was exactly the same with all 4 of them. If the red interlock is not in place, someone could damage your motor. Or get hurt.
 
Another little detail that got me confused and would like to clarify:
Here are the two types of tiller arms used on these motor for the 87 model and for the post 91 models (source: Leroy Ramblings):



My motor IS an 87 (verified with the letters "CU" on model #), yet it has what Leroy show as a post 91 tiller arm, with the kill switch at mid section and side of arm....
Has my control been replaced with a 91 and up model type? Or is this a rare accuracy glitch on Leroy's Master piece?....
 
Sounds like a previous owner has tinkered with this motor a bit. If it were me, I'd track down all the control linkages including the previously mentioned pawl to make sure all the safety measures are in place.

KJ
 
kevinj said:
Sounds like a previous owner has tinkered with this motor a bit. If it were me, I'd track down all the control linkages including the previously mentioned pawl to make sure all the safety measures are in place.

KJ
Click to expand...

Thanks.
Other than the starter pawl (and the kill switch which is working fine) what other safety measures are you referring to?
 
That's basically it. If that pawl is not in the correct position you can start the motor in gear which could be very bad. Also checking to see if that is playing a part in your ability to give excess throttle when starting because you could over rev the engine when cold....also a bad thing.

KJ
 
The pawl on the red spring thingy prevents pulling the recoil if throttle is too far advanced.-----Motor will start in gear at idle speed I believe.
 
racerone said:
The pawl on the red spring thingy prevents pulling the recoil if throttle is too far advanced.-----Motor will start in gear at idle speed I believe.
Click to expand...
Thanks racer, now as I was saying in my opening post, in this case there is NO throttle opening possible at all in neutral.
Motor starts fine like this, which is why I was asking if it was a factory setting that got put in place after the older motors that DO have a bit of throttle opening in neutral for starting purposes (and marked on the tiller arm with the word "Start" imprinted).

Timguy's response seems to indicate that it is the case, and that is the factory setting as he observed (and modified to allow "some" throttle opening) on his 87's....

I will also double check the start in gear thing later when I get home, but I don't believe I am able to pull the recoil if in gear as it is.
I did put an older recoil I had on the bench (pre-red pawl) on it, but I did manage to tuck the red pawl and its spring behind the rope guard (I will try posting a pic later), so the pawl might actually serve its purpose since it is under tension.
 
This motor is still overheating, I measured temp going all the way to 190 and climbing yesterday on the bottom cylinder, so I shut it off and looking for the right thermostat. Can someone confirm which part number it is? (It is the one encapsulated in black plastic, not the one that lets you see the spring inside the metal housing).
I was looking at [h=2]Sierra International 18-3500 Thermostat, but then the description says it's for 3 cylinder engines...[/h]
 
???-----It is quite common for basic parts to fit a multitude of motors.---Another example is a flywheel key , same key is used some years on 9.9 to 300 hp models !!
 
racerone said:
???-----It is quite common for basic parts to fit a multitude of motors.---Another example is a flywheel key , same key is used some years on 9.9 to 300 hp models !!
Click to expand...

Oh I understand that, problem is the number of listings for this part that do not mention the 87 9.9hp... but s'all good now, just gonna order it.
Any difficulty in replacing this? I read on Leroy's that the rubber gasket tends to be a challenge to replace as it is pressed pretty firmly in there?
 
Jupiter Dinghy said:
This motor is still overheating, I measured temp going all the way to 190 and climbing yesterday on the bottom cylinder, so I shut it off and looking for the right thermostat.
Click to expand...

It looks like part# 5005440 is the correct thermostat for early production 1987 9.9: http://www.marineengine.com/newparts/part_details.php?pnum=OMC5005440

Part# 0433379 is for late production 9.9's. http://www.marineengine.com/newparts/part_details.php?pnum=OMC0433379

I haven't the first clue how to decipher early vs late production so I can't help there.

Just an odd ball question here, but when you did all your initial work, did you check the water tube grommet? It's part#55 on this diagram: http://www.marineengine.com/parts/j...turer=Johnson&section=Midsection+(10sel+Only)

I fought constant heat issues on my '79 9.9 and replaced gaskets, thermostat, etc and still had problems. Joe Reeve pointed me to that grommet which has a tendency to deform and block water flow. I'm no sure if that flaw still existed in the '87 models but after replacing that little $11 rubber piece all of my problems were gone.

Also, when you first cleared that water flow obstruction, where was it located? On mine I did find some crusty stuff in the exhaust cover plate on the starboard side of the engine. If you haven't had that off you might check that too.

KJ
 
Early production had the cylinder head with long cover and thermostat at the bottom.---Late production had an easy to get at thermostat at the top.----Get the correct one !!
 
The top mounted thermo will blow off its seat at higher rpms. If yer getting 190f at speed I'd check that grommet...if the impeller is still good.
 
Thanks all, I got the new thermostat, still overheating. A bit less, but still getting in the upper 170's and I have a very weak squirt coming out of the pee hole with the water being very hot to the touch, while the water coming out of the exhaust hole is cold. On my 79, which is cooling fine, it's the opposite: Water out of the pee hole is cold and out of the exhaust hole warm (but not hot).
So I definitely still have a restriction, as Kevin says there is a lot of "crusty stuff" in the water passages, I thought I had cleared the water tube but I will have to check this grommet I guess. What is involved for its replacement? Does the powerhead have to come off or can I remove the tube from the midsection through the bottom?

BTW, it is the top mounted stat on this motor, and the old one was completely destroyed.... came out in pieces! (433379 it is).
 
Jupiter Dinghy said:
...I have a very weak squirt coming out of the pee hole with the water being very hot to the touch, while the water coming out of the exhaust hole is cold.
So I definitely still have a restriction, as Kevin says there is a lot of "crusty stuff" in the water passages, I thought I had cleared the water tube but I will have to check this grommet I guess. What is involved for its replacement? Does the powerhead have to come off or can I remove the tube from the midsection through the bottom?

BTW, it is the top mounted stat on this motor, and the old one was completely destroyed.... came out in pieces! (433379 it is).
Click to expand...
Glad you found the bad T-stat and thanks to RacerOne for the ID help.

A weak water stream is one sign of a deformed grommet. On my '79 I had a weak tell-tale stream when the engine was cold even with a new water pump. Once the T-stat opened up the stream was completely gone and I had almost no water coming out the exhaust.

Cold water coming out your exhaust seems weird unless there is still some other restriction in the water passages. When you cleaned the exhaust cover, did you also remove the inner exhaust plate (#24 on the diagram) and clear the passages in the cylinder? http://www.marineengine.com/parts/j...urer=Johnson&section=Cylinder+&+Crankcase I found pieces of old impeller lodged in my cylinder passages.

To replace the water tube grommet you have to take the powerhead off the mid-section. Disconnect the fuel line, throttle linkage, and rope start. There are 4 bolts on the underside that hold the powerhead down. You'll need to get a new grommet (#55) and base gasket (#92) for this job. http://www.marineengine.com/parts/j...turer=Johnson&section=Midsection+(10sel+Only)

While you have it off, also remove the lower unit and run a wire through the water tube. There possibly could be pieces of junk lodged in there causing a restriction. Once you've done all this I can't think of anything else water related that would be your cause of overheating on the top cylinder.

KJ
 
kevinj said:
Glad you found the bad T-stat and thanks to RacerOne for the ID help.

A weak water stream is one sign of a deformed grommet. On my '79 I had a weak tell-tale stream when the engine was cold even with a new water pump. Once the T-stat opened up the stream was completely gone and I had almost no water coming out the exhaust.

Cold water coming out your exhaust seems weird unless there is still some other restriction in the water passages. When you cleaned the exhaust cover, did you also remove the inner exhaust plate (#24 on the diagram) and clear the passages in the cylinder? http://www.marineengine.com/parts/j...urer=Johnson&section=Cylinder+&+Crankcase I found pieces of old impeller lodged in my cylinder passages.

To replace the water tube grommet you have to take the powerhead off the mid-section. Disconnect the fuel line, throttle linkage, and rope start. There are 4 bolts on the underside that hold the powerhead down. You'll need to get a new grommet (#55) and base gasket (#92) for this job.http://www.marineengine.com/parts/j...turer=Johnson&section=Midsection+(10sel+Only)

While you have it off, also remove the lower unit and run a wire through the water tube. There possibly could be pieces of junk lodged in there causing a restriction. Once you've done all this I can't think of anything else water related that would be your cause of overheating on the top cylinder.

KJ
Click to expand...

Thanks again for the great info and sharing your experience Kevin.
I didn't touch the exhaust plate so it's on my list now.

To clarify: Both cylinders overheat. The bottom one just a bit more than the top one, but not by much now, only like 5 deg. F difference.

I did run a metal rod inside the water tube (after I connected a water hose to it and saw that no water was making it through the tell-tale) and could feel some obstruction in there, after doing this and lowering the motor back to vertical, some brown/'orangy" colored water ran out of the tube. I reconnected water hose and then had a tell-tale stream, weak, but a stream was there. So next, I ran a metal wire through the pee hole (with the hose still connected and feeding the tube) and then the water squirted out of the hole 4 or 5 feet away, so I thought I had fixed the problem then.

I won't have time to take it apart until next weekend, but I'll keep you updated on my findings, thanks again!
 
Jupiter Dinghy said:
I didn't touch the exhaust plate so it's on my list now.

To clarify: Both cylinders overheat.

I did run a metal rod inside the water tube (after I connected a water hose to it and saw that no water was making it through the tell-tale) and could feel some obstruction in there, after doing this and lowering the motor back to vertical, some brown/'orangy" colored water ran out of the tube.
Click to expand...
Now we're getting somewhere.

The inner exhaust plate has to come off. I'll bet anything you have pieces of junk clogging passages around the exhaust ports.

If you ran that wire up to the powerhead and got junk to come loose I would highly suspect the grommet is bad. While you have the powerhead removed go ahead and pull the head off and check all around the cylinder. It could be that you have junk everywhere and need to do a good thorough cleaning.

KJ
 
kevinj said:
Now we're getting somewhere.

The inner exhaust plate has to come off. I'll bet anything you have pieces of junk clogging passages around the exhaust ports.

If you ran that wire up to the powerhead and got junk to come loose I would highly suspect the grommet is bad. While you have the powerhead removed go ahead and pull the head off and check all around the cylinder. It could be that you have junk everywhere and need to do a good thorough cleaning.

KJ
Click to expand...

Yeah, that's what I think too. Never removed a powerhead on these yet, that'll be a first.
Any tips? Tricks of the trade? How many / which gaskets do I need to get ready to replace when reassembling? I see 2 on each side of exhaust plate, and obviously the head gasket. Suppose there's more between powerhead bottom and mid section?

As far as breaking the junk probably clogging the passages everywhere, what is the best way to do this so I don't just push it in deeper in? Vaccum? Shoot water from hose up the tube intake?

Thanks once more!
 
Jupiter Dinghy said:
Yeah, that's what I think too. Never removed a powerhead on these yet, that'll be a first.
Any tips? Tricks of the trade? How many / which gaskets do I need to get ready to replace when reassembling? I see 2 on each side of exhaust plate, and obviously the head gasket. Suppose there's more between powerhead bottom and mid section?

As far as breaking the junk probably clogging the passages everywhere, what is the best way to do this so I don't just push it in deeper in? Vaccum? Shoot water from hose up the tube intake?

Thanks once more!
Click to expand...
You'll need the grommet (part#330426) and powerhead to exhaust gasket (part#325721) that I referenced in my previous post. Also the head gasket, and you're right about the exhaust plate there are two gaskets used for that.

There's really nothing major to removing the powerhead on these little motors. Throttle linkage, fuel mixture adjusters, and fuel line is about all that has to come off. Simply remove the 4 bolts on the under side of the lower cowling and it comes off easy.

A shop vac is a great way to pull out any sizeable pieces of junk. A small pointed pick is a good tool to dislodge smaller pieces in other passages. I would not shoot water through for fear of forcing something back into the cylinder. Instead, get a blower gun for your air compressor that has a pointed rubber tip. Press the tip into the passage opening and then shoot in air to remove and stuff plugging the opening.

KJ
 
racerone said:
4 bolts or 6 bolts ? ----Write down the location and length of the bolts too , they are not all the same length.
Click to expand...
Good catch, I had 4 stuck in my head but it is 6 bolts. And yes, do keep track of the length as there are 2 different sizes. Still a fairly straight forward job.

gasket.JPG

housing.JPG
 
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