evinrude 9.9 1979 poor idle,loud exhaust,less power

[Hughjohnson]

Re: evinrude 9.9 1979 poor idle,loud exhaust,less power

OK I took the engine out of the exhaust housing. The gasket looks fine and the metal faces. Now there is a lot of greasy black carbon on the outside of the Inner exhaust chamber from the top to about 2/3 rds of the way down. At the bottom of the Inner exhaust chamber there is a lot greasy milky emulsion. Does that mean anything.the rubber gasket at the bottom of the inner exh chmbr looks good.I have photos but I cannot figure out how to send them.I checked the FAQs to no effect. I have the pictures in my computer.
I have not removed the crankcase head with its seal yet.
Sorry I got mixed up in my last e mail I meant loss of suction in the crankcase not the cylinder. your post explained very well.I will try tomorrow if I can rig up an seal puller.

 

[OptsyEagle]

Re: evinrude 9.9 1979 poor idle,loud exhaust,less power

The carbon is not a big deal. If you look at mine you can see these things get pretty grundgy.
The milky emulsion could be a different story perhaps indicating water that got into the cylinder and eventually shot out the exhaust. To attach pictures just click "reply", then "Go Advanced" and then right below click on "Manage Attachments". That will allow you to upload pictures.

 

[OptsyEagle]

Re: evinrude 9.9 1979 poor idle,loud exhaust,less power

I should add that water will be there anyways because this is where the cooling water exits as well. All the same the pictures may be helpful.

 

[Hughjohnson]

Re: evinrude 9.9 1979 poor idle,loud exhaust,less power

thanks . I have tried the photos but they are too big in Megabytes to go thru and I am trying to figure out how to cut them back. I cannot work on engine for a day or two and then I'll be back

 

[Hughjohnson]

Re: evinrude 9.9 1979 poor idle,loud exhaust,less power


These are photos showing condition of pistons,cylinder,head and gasket. Do you think this could be leaking water ?

 

[raczekp1]

Re: evinrude 9.9 1979 poor idle,loud exhaust,less power

do the head flatening.it may be wraped.two times i had to remove 0.4 mm of head surface
in case change gaskets at water jacket.
i did this gaskets by myself

 

[OptsyEagle]

Re: evinrude 9.9 1979 poor idle,loud exhaust,less power

Well, maybe others will comment, but I would say that shinny cylinder certainly looks like water is getting in to me. Is that the bottom cylinder?

Tough to say if it is getting by the head gasket. You could try resurfacing the head again, a new gasket and ensure the torque values are correct. Do about 33% of the torque all around in a spiral fashion, then again with another 33% of full torque and then one last time for the last 33% of the recommended torque.

As for other ways water can get in. Perhaps a crack in the cylinder wall. Did you ever take a compression reading of this motor?

 

[Hughjohnson]

Re: evinrude 9.9 1979 poor idle,loud exhaust,less power

Thanks for quick reply.Yes I will sand head again after checking for warp. I had 8 thou in apr 2010.
I assume by water jacket gasket you are referring to the cyl head or not ??
The shiny cyl is the bottom cyl. what is interesting is that in 2010 when I know I had a leaking cyl head and water was in the lower cyl the piston was black and only the head was clean Now the piston is white.
yes I will put on new cyl head gasket.
compression check showed 110 and 120 psi.
cracked cyl wall yuch I'll have a look.
Do you know how exhaust get out of the inner exhaust housing and back up the outer housing . It then comes out of 2 small holes at the top rear of the housing. usually when in reverse. I cannot see how it gets past teh rubber gasket at the bottom of the inner housing where it joins the gear housing.

 

[raczekp1]

Re: evinrude 9.9 1979 poor idle,loud exhaust,less power

i'm refering to this gaskets where pee outlet is located.in this side panel there are 2 gaskets.
and on the oposite side of block there is 1 gasket.
but to cange this water jacket gasket you have to pull out the powerhead

 

[Hughjohnson]

Re: evinrude 9.9 1979 poor idle,loud exhaust,less power

Thanks for clearing up the gaskets . Yes I know those three as I cleaned out all the blocked waterways in April 2010 and resurfaced the faces and put in new gaskets. they all look good from the outside so I think I will leave these.
I have refiled and sanded the head on glass. It might have been about 2 thou warped in the middle but looks great now.
I removed the bottom seal on the crankshaft . It looks very good and I think I replaced it in apr 2010.
So I am now about to put the whole engine back together because I think we are all out of ideas except for a cracked cylinder wall or cylinder head. I know they are difficult to see and I have used a jewellers eye glass and can see no sign of cracks.
Do you advise putting gasket cement on any of the joints. I assume the cylinder head should be dry.
Thanks for all your continuing help.

 

[Hughjohnson]

Re: evinrude 9.9 1979 poor idle,loud exhaust,less power

OK I put the engine back together in a water tank and it started fine but exactly the same as before. poor idle and noisy exhaust.Pulled off the lower plug wire and engine kept running. Pulled of top plug wire and engine stopped. Tried to start the engine with only the bottom cyl plug connected and it very occasionally fired but very occasionally. took out the bottom plug and it showed no signs of water but was wet with gas mixture and showed some fresh soft carbon which was a surprise as the engine only ran for 2 or 3 minutes in total. took off bottom plug wire and connected new plug on outside of engine -ran the engine on top cyl and the spark was excellent strong and blue. I am really stuck guys and just do not know what to do next and I do not think I have missed any advice if so please let me know.

 

[the machinist]

Re: evinrude 9.9 1979 poor idle,loud exhaust,less power

Without going back & re-reading all of the suggestions which may have been already covered, if you are not getting consitant firing on one cylinder, it could be a electrical problem. Could be as simple as a bad wiring connection inside the spark plug boot, to a bad coil, or even a bad ground under that coil. OR a bad powerpack.

Thes motors run suprisingly well on one cylider in a tank or on muffs, however hard to idle, but put them on a boat in the water they loose power & run like crap.

As for noise, if it is being run on muffs, YES you will hear a loud exhaust because the water is not muffling it.

 

[Hughjohnson]

Re: evinrude 9.9 1979 poor idle,loud exhaust,less power

Machinist so glad to hear from you again.Yes it ran well for the last 2 months of summer at 5 knots vs 6.2 with 2 cyl. I will exchange coils and HT leads. It is in garbage can of water and the bark comes from the 2 holes at the top of the housing. thanks agoin

 

[OptsyEagle]

Re: evinrude 9.9 1979 poor idle,loud exhaust,less power

Well Hugh, I have to assume that you are still getting water in the cylinder. That picture you took below is showing the shinyiest cylinder I have ever seen. Something was cleaning it. Obviously it must not be a leaking head gasket since I think you changed that at least once, if not twice and resurfaced the head as well, if I recall.

Perhaps a leak in the exhaust cover. Unfortuneately I think the powerhead may need to come off to remove the exhaust plate. I have never tried to remove that plate personally. You could just try re-tightening all the exhaust cover bolts and see if that seals it up any.

 

[Rick.]

Re: evinrude 9.9 1979 poor idle,loud exhaust,less power

Well Hugh, I have to assume that you are still getting water in the cylinder. That picture you took below is showing the shinyiest cylinder I have ever seen. Something was cleaning it. Obviously it must not be a leaking head gasket since I think you changed that at least once, if not twice and resurfaced the head as well, if I recall.

Perhaps a leak in the exhaust cover. Unfortuneately I think the powerhead may need to come off to remove the exhaust plate. I have never tried to remove that plate personally. You could just try re-tightening all the exhaust cover bolts and see if that seals it up any.[/QUOTE

Good idea. Tightening the exhaust cove bolts worked well for my 79 - 9.9 that was getting water in the lower cylinder.. Give it a try. Your doing the right thing toward the spark issue I think. Rick.

 

[L.A.Wise]

Re: evinrude 9.9 1979 poor idle,loud exhaust,less power

Hey guys, I've been following your discussion, and there is nothing I can add to your diagnosis. But I did want to state that if you have an O'Riely's auto parts near you, they will run compression tests for you if you take the motor to their shop. Don't want to do that, they will let you place a deposit on a compression tester (actually they charge you the price of the tester, but refund your money when you return the equipment). Also, they have spark plug testers they sell at less than eight dollars each. I have a couple of their compression and spark testers that accompany each boat I have (3).

 

[Hughjohnson]

Re: evinrude 9.9 1979 poor idle,loud exhaust,less power

thanks for your continuing support.I talked to an outboard mechanic where I buy my parts and he said that if a cylinder was run for some time without firing the fuel would clean the surfaces. He also thought that if there was water in there you would see it on the plug. we have seen no sign of water on the plug and it has been in and out a few times as we experimented. Today we ran the engine on one cylinder with the bottom spark plug out for some time and apart from an amazing spark display from the end of the plug right at the spark plug hole we saw no water vapour or droplets. I did expect to see the gas vapour from the hole ignite but it did not. AHA I thought--no gas. But I tried the same experiment on the top cylinder and there was no flame and I know that cylinder has gas cos the engine runs very well on that cyl alone.
re water in from the exhaust cooling gaskets. When I had the engine out last week I checked these bolts and I only replaced these gaskets in 2010 so I am confident that they are not leaking.( that does not mean they are not but it it is not at all likely and we have no water showing on the spark plug.)
Now once again we tried starting the engine with just the bottom cylinder and it does fire occasionally.there is lots of spark. Now could it be a timing issue ? I don't know yet how the ignition works (CD type ) . Is it possible that the bottom timing could be out even if the top is OK. I took the flywheel of late this afternoon but I am not sure what I expect to find . tomorrow I'll take the coil off and check the play on the stuff that rotates .Now I am flying blind.
Is there any way that the fuel mixture could be wrong for the bottom cyl different from the top cyl ??
As you see I am stuck but very determined to find the solution.

 

[Hughjohnson]

Re: evinrude 9.9 1979 poor idle,loud exhaust,less power

Sorry L.A. Wise I did not reply to your post. Compression is 120 and 110 and spark is 7/16 of an inch and equal on both plugs. thanks. .

 

[AlTn]

Re: evinrude 9.9 1979 poor idle,loud exhaust,less power

will the bottom coil work on the top cylinder?..if so, it's not a coil problem....if it's not a coil problem, the great likelihood is that the problem rests in the powerpack, but first, unplug each connection and make sure no pins have been pushed down and that the pins and sockets are clean and tight, the coil grounds are clean and shiny on the block as well as the powerpack ground screws.

Look for an explanation provided by F_R concerning the workings of the CD Ignition. It's concise and clear. Nutshell is..the trigger or sensor coil sends a voltage of ~.5 v to the pp for a firing signal. The charge coil sends ~150 v. minimum to the pp for ignition as it's sent to the coils for further voltage increases, then on to the plugs. The pp serves as a storage and switching unit by storing the the charge coil voltage and, using the triggering voltage from sensor coil, sends it to each coil on cue. Unless a wire is pinched under the flywheel or something of that nature, nothing under the flywheel will cause the firing of just 1 cylinder on a 2 cylinder engine.
If you wish to determine which component of the ignition system is at fault, you need to purchase or make a dva adapter < plenty or posts concernig that by using the search function >..or your multimeter may already be capable of doing this.
CDI electronics offers a troubleshooting chart on their website for your ignition.
Try the coil swap first..if it proves to be good..then the odds are the pp is bad. If it proves to be bad, then put the top coil on the lower cylinder and check for spark. If it works..then the bottom coil was bad and that's all. If it doesn't then the pp is the likely culprit again as well as the bottom coil being bad as it didn't work in the top cylinder. Confusing, huh?...not really if you think of the paths for the top and bottom being 2 separate circuits through the pp. One path is working and one isn't if only the good coil works on 1 cylinder.
I was where you are now on a 78 9.9 a couple of years ago...bought the dva adapter as well as a jumper wire set from cdi...had a bad pp and 1 bad coil...replaced the pp and both coils with ones from cdi..no problems since then.

 

[Hughjohnson]

Re: evinrude 9.9 1979 poor idle,loud exhaust,less power

OK so after a few days delay because of other problems i got back to the engine. I swapped the upper and lower coils by cutting and swopping the two 2 orange wires from the power pack to the 2 coils. I then swapped the 2 high tension spark plug leads. so now we have the bottom coil feeding the top cylinder and vice versa for the other.the result was the same as before. the bottom cylinder was not working and the top did all the work. therefore the coils are OK and I believe it also proves that the power pack and sensor coils are OK too. Now AlTn you suggested that the pp could still be at fault.I cannot see how that can be if we have tested each of half of the pp output by swapping coils and HT leads. am I missing something ??
I am now stuck again for ideas. can it be the reed valve on the bottom cylinder ??