odd problem with evenrude 9.9

dave208

Cadet
Joined
Mar 2, 2007
Messages
15
I bought a used 9.9 last year. The motor was on a boat and the owner had tried to start the motor with no luck. The pull cord recoil spring was broke and a can of either was laying in the boat. The price was right, so I bought the whole rig. I replaced the recoil spring, took the carb apart and the float needle was stuck. I cleaned the carb up and started the motor in a test tank. The water pump was history, so I replaced it. After starting the motor a second time, I noticed the water jacket was leaking through the gasket back by the spark plugs. When I snugged the bolts the engine actually picked up in rpm. I used the motor through the summer a couple times. It runs wot fine, but does not idle well. I believe the motor had been run hot at one time or another, because the paint on the head is slightly wrinkled. Proably because of the water pump. It is a bear to start cold, but runs well after initial startup. I think the head gasket may have a small leak since I noticed the rpm issue noted above when sealing the water jacket. Would replaing the head gasket be wise, or should I consider a complete gasket replacement? I believe the motor is worth putting a few bucks into since I bought it so cheap. I don't want to run the motor and burn the cylinder head. Opionions please.
 

Xcusme

Commander
Joined
Apr 21, 2003
Messages
2,888
Re: odd problem with evenrude 9.9

Welcome to iboats Dave.....
I'd plan on replacing the head gasket. When you have the head removed, you can inspect the cooling passages, cylinder walls and check the head and powerhead for flatness with a straightedge. No use putting a new gasket on a warped head. Do a compression test after the head gasket to get a baseline reading. As for the low idle performance, it could be a carb issue. It's best to clean carb internals with carb cleaner, followed with compressed air. Install a carb kit and set initial needle adjustments.

Since you didn't post a model number of your motor, it's impossible to question the ignition system beyond checking for good spark at the plugs. Older motors had magneto ignitions, newer have electronic ignition. A small plate on the transom bracket has the model number. If it's missing, find a quarter sized disc on the powerhead (welch plug) , the model number is stamped into it too. A OEM service manual is a big help in maintaining your motor.
 

mikesea

Lieutenant Commander
Joined
Oct 1, 2006
Messages
1,830
Re: odd problem with evenrude 9.9

replacing the head gasket may fix your problem completly,is obvious the gsket was blown,and you dx'd it well.More than likely overheated becuse of bad impeller,those 9.9 andthe 15 are prone to having the impeller hub break loose from the rubber.I suggest tking the head off,you can get a piece of 80 grit,emery paper ,try and find a piece of flat tile or marble and lay the emery on it,make figure 8 pattern with the head to give it a new surface,try and note after a minute or 2 how the process is going,if the head warped ,you will notice not all the surface is getting treated,thus warped,be sure its flat and keep going ,Idea is once the whole surface has indication of treatment ,your done,if there are a few spots here and there not getting it,dont worry,the gasket will help. be sure all the bolt holes are clean so when you tighten you will get an even torque,you want to use a torque wrench if you dont know the torque spec. just ask someone will have it,or I will check in my shop.Before you start with the 80 grit.Be sure to scrape all the old gasket material off and any grease etc,you dont want to dirty up the grit with gunk.Be sure the engine block side is clean,I like to use a one edge razor blade and scrape off all gunk,it would be nice if you could resurface the block too,but space wont allow it and its usually the head that warps,one last thing,on some engines,the roller cam off the carb wears out,they had a plastic piece that would be almost see through,it was a different material then the roller itself,if the plastic "insert wore or broke off,the timing of the roller was effected greatly,also the plastic piece under the flywheel sometimes breaks off,the problems mostly effect the idleing,some carbs had plastic pick up tubes tht were in the bowels,they too break off
 

dave208

Cadet
Joined
Mar 2, 2007
Messages
15
Re: odd problem with evenrude 9.9

I was able to retrieve the serial no from the evenrude, but I cannot make the model no. Someone in the past scrapped something across the face of the number sticker making it almost illegible. The serial number agrees with the number on the welch plug. "G02987187". I have not had time to see if I can identify the year of the motor from the serial number. It is a shame the way people treat equipment. I have a short shaft 9.9 johnson made in 74 that will run so slow you can watch the prop turn. I have put unkown hours on that motor with very little problems over the last 20 years. The evinrude is a much newer motor, and was treated terrible. Some people have no value for anything.
 

OBJ

Supreme Mariner
Joined
Dec 27, 2002
Messages
10,161
Re: odd problem with evenrude 9.9

Dave, take a look on the block for the large silver colored welch plug (some will call it a core plug). The model number maybe there depending on how new it is.
 

dave208

Cadet
Joined
Mar 2, 2007
Messages
15
Re: odd problem with evenrude 9.9

I was able to identify some of the model numbers using a black light. The numbers were stamped right at the edge of the space where they were supposed to be, and were heavily scratched:
XXXFEEIR
EL R
H
The 3 "X" are numbers that are VERY hard to read, the fourth digit is either F,R,or H, from what I can make of the numbers, I think it is a 1991. Hope someone can shed some light on this best shot.
 

OBJ

Supreme Mariner
Joined
Dec 27, 2002
Messages
10,161
Re: odd problem with evenrude 9.9

How 'bout E10ELEIR?

Electric start, Long shaft ...91' ....R is the model run.
 

dave208

Cadet
Joined
Mar 2, 2007
Messages
15
Re: odd problem with evenrude 9.9

I believe we may have a winner. Thanks OBJ. I think I am very close here, but it is pull start. I will look at the 91 numbers and see if I can sort out the pull start issue.
My other 9.9 johnson I always thought was a 1974 model. I was trying to find the model number to verify the year, but had no luck. The model no on it is"10824M". Serial is "E0004612". I could not find any numbers that come close to matching this motor. The number plate is very clear on this motor. I bought it used and I think it came from Canada originally. The previous owner mentioned he had bought the motor up north on a fishing trip when his original motor quit on him. He said it was a 1974, but I don't think he was certain, as he had 3 different motors in 9.9. I would like to do some work on this motor, but I am afraid to order parts on the net without knowing the year for certain. All the numbers I looked at were combinations of letters and numbers. This only has one letter. Maybe we can shed some light on this motor. I usually deal with a local johnson shop where the best bet is to take the part with you to get the right replacement. They have the saddest part storing system I have ever seen. If the owner isn't on site the chances of getting the right part is pretty slim. With the computer power of today, I don't know why they don't inventory. The owner is about 70 years old and it is a howl watching him trying to find parts. One gets no price breaks at that shop.
 
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