1997 Merc 4-Stroke 9.9HP ring problem?

[beeheck]

I have a merc 9.9 4-stroke and it won't stay running, took it in for repairs and the mechanic told me he didn't have time to work on it but Mercury gave him a formula to put in the gas to free up the rings which he says are "froze in". I'm thinking I need to replace them. So, I have two questions, how hard is this for a person who is handy and has some motor experience, (not outboard). Second, which brand name of repair manual is considered to be the best? I see some but they are for several different motor sizes and years. No one offers a specific repair manual for this motor?

 

[carholme]

Re: 1997 Merc 4-Stroke 9.9HP ring problem?

What is the s/n of your engine?

Better still go here and you will see two 9.9s listed in the second column under Four Stroke.

http://1manual.com/Mercury manuals/Service_Manual_Index.html

Gerry

 

[Don S]

Re: 1997 Merc 4-Stroke 9.9HP ring problem?

http://1manual.com/Mercury manuals/Service Manual PDFs/FourStroke/827857r1/cover.pdf this is the manual you need, it's for motors up to 99. You will need to open the outline and download each section seperately.
You might want to find out "How" the rings were frozen, if from carbon, you do not need to take it apart. Power tuner (Merc Brandname) will do the job if they aren't too bad. If the rings are rusted, that's another thing, and you need to find out why there was water in the cylinders before you take it all apart.

 

[beeheck]

Re: 1997 Merc 4-Stroke 9.9HP ring problem?

Wow, thanks to both of you! It's guys like you that restores a persons faith in forums. It's a big help, thanks again.

 

[Star]

Re: 1997 Merc 4-Stroke 9.9HP ring problem?

Dear Beeheck,
I don't believe the diagnoses is correct. Fuel problems are more like it. Get some seafoam at the auto store. Fill the carb bowl through drain port. Let it sit for 15 minutes then drain. Refill with fresh gas ahd see what happens. Tearing down the carb is better but this may work.

 

[johnevinrude]

Re: 1997 Merc 4-Stroke 9.9HP ring problem?

have you ever washed out the gas tank? steel tanks and plastic tanks all collect moisture over time or left uncovered.ive had the same problems of not staying running,and then run good for a whle, it was just dirty gas/!

 

[beeheck]

Re: 1997 Merc 4-Stroke 9.9HP ring problem?

Here's an update... took it to the local dealer, he decided he didn't have time to work on it so I took it to the mechanic at work. I got a compression Gage and we did a compression test. 150 both cylinders, did this a couple times always the same results, 150 psi. Squirted oil into each cylinder and repeated test, more oil and repeat test, always the same 150 psi both cylinders. Carb was a little dirty but not as bad as I thought it would be. A few things in where the jets are but easily blowen out. There was a "slime" very thin but on every thing some spray carb cleaner took it right off. The mechanic striped it down to all parts out, cleaned it and put it back together, tested the starting solenoid that works off heat? and it worked OK according to the book I downloaded which was suggested from here. Thanks again for that! Motor is a kicker on a Lund Baron and it runs off the same tank as the 200hp merc. It just has never been used. Bendix on the starter has no wear on it, several people have thought it is a brand new motor. All paint on the motor looks brand new, no discoloration from heat or use. I have had several people tell me to put seafoam in the gas and run the heck out of it. Might just have to do that.