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9.9 hp Mariner 4 stroke 1998

S

skeeter12

New member
"I have had a problem with my 9.9 kicker all summer. This last spring I took the motor to a marina to have them work on it. Problem started out like this. Run along and it would either stall or almost stall. If I got to the gas squeeze bulb and squeezed it before it would stall it would run along for a few min. I could not run it wide open it would stall. Ok. They worked on it and said they found something in the seat plugging it off. They said they over hauled the carb. Would sit in the tank and run fine. Take it out to troll and it would die. Took it back and they tear it appart again. Found nothing. Put it in the water at the ramp and it would run but it wasn't under load. I paid again. Took it out and same thing. Run along and die. Well I desided to tear into it myself. Wasn't easy to find parts but did find some of them right here on this site. I replaced the float, I replaced the pin that goes through the float because it looked like someone pounded it in and was bent. Was hard to get out. I replaced it thinking got it now. I replaced the seat although I could not find the needle. Replaced the squeeze bulb and hose and even the piece that the gas line connects to on the motor. Put a 10 micron filter in it. Replaced two rubber pieces in the fuel pump. Ran it in my garage in a garbage can it purs like a kitten. I go out fishing the motor wouldn't start so I used the electric that day. Come home had had wife turn key while I chocked it at the motor starts right off. All set now, I go fishing. Motor starts right up and runs for 2.5 min and I have to squeeze the bulb again. Every 2.5 sec squeeze bulb. Got tired and discourged and came in. ANY ideas out there ANYTHING before I have a nervous breakdown????? Even call me if you can or email me. I hate thing broken down.. Thanks so much in advance for any help. Nels Larsen Midland, MI 989 837 2681 or [email protected]"
 
"Yes, I doubled checked that.

"Yes, I doubled checked that. Appreciate your help. Nels

Am hunting for a 825470T fuel pump at this time."
 
I don't know if it is the

I don't know if it is the fuel pump but I found one and am going to put it on. Then I can rest assured it that isn't the problem.. To be honest I have already put the diaphragms in the old pump. Still had the problem. So the search is on for the problem.
 
Went out this afternoon and re

Went out this afternoon and replaced ALL hoses all the way to carb from the tank. Cut the hoses open and found nothing wrong with the inside at least what I could see. I then pumped up the bulb hard. Oh one thing I did notice is I tried to blow into the gas tank using the hose and I couldn't. I hope there is a check valve there. Must be because I could suck gas up.
 
"Ran it at the dock. same prob

"Ran it at the dock. same problem.
I don't know what it is yet but sure can tell you a lot of things it isn't.
Waiting for new fuel pump now. Nels"
 
Guy told me to unhook fuel lik

Guy told me to unhook fuel like form kicker and pump bulb up let it set all night and it should be hard in morning. So I did. From now on when I go fishing I will first have to find a primer guy to go along. Lolol Bill B. The bulb was hard this morning. SO I would have to think everything down there would be ok. I can easily suck gas up through so should be no problem there. This is starting to be like a mystery book. Stay tuned for next chapter FUELPUMP. Nels
 
The carb on my 98 mariner is e

The carb on my 98 mariner is exactly the same one on the 93 Yamaha. Parts are half price about and you can find them easy. Figure that out! Most everything you look for on the Mariner is NA.


Just to give an update in case anyone else finds the same problems I have. Mercury doesn't make hardly any parts for this motor. In fact the power head is a 1993 Yamaha. Wonder how much the Mercury sticker cost the original owner lol. Anyway if your looking for parts for this motor check yamahas website for a 1993 F9.9MLHR. The good news are the parts are cheaper. I bought a front support for my top cowling that cost me in the range of $150 including shipping the same part is 43 from yamaha. and that "starter assembly" I need is $107 from Mercury but NLA. Yamaha has it for $79.00.
 
"The problem most often seen w

"The problem most often seen with fuel pumps is fuel starvation, hesitation or missing due to inadequate fuel pressure/delivery. In extreme cases, this might lead to a no start condition, but that is pretty rare as the primer bulb should at least allow the operator to fill the float bowl or vapor separator tank). More likely, pump failures are not total, and the motor will start and run fine at idle, only to miss, hesitate or stall at speed when pump performance falls short of the greater demand for fuel at high rpm.

Before replacing a suspect fuel pump, be absolutely certain the problem is the pump and NOT with fuel tank, lines or filter. A plugged tank vent could create vacuum in the tank that will overpower the pump's ability to create vacuum and draw fuel through the lines. An obstructed line or fuel filter could also keep fuel from reaching the pump. Any of these conditions could partially restrict fuel flow, allowing the pump to deliver fuel, but at a lower pressure/rate. A pump delivery or pressure test under these circumstances would give a low reading that might be mistaken for a faulty pump. Before testing the fuel pump, refer to the testing procedures found under Fuel Lines and Fitting to ensure there are no problems with the tank, lines or filter.

A quick check of fuel pump operation is to gently squeeze the primer bulb with the motor running. If a seemingly rough or lean running condition (especially at speed) goes away when the bulb is squeezed, the fuel pump is suspect.

If inadequate fuel delivery is suspected and no problems are found with the tank, lines or filters, a conduct a quick-check to see how the pump affects performance. Use the primer bulb to supplement fuel pump. This is done by operating the motor under load and otherwise under normal operating conditions to recreate the problem. Once the motor begins to hesitate, stumble or stall, pump the primer bulb quickly and repeatedly while listening for motor response. Pumping the bulb by hand like this will force fuel through the lines to the vapor separator tank, regardless of the fuel pump's ability to draw and deliver fuel. If the engine performance problem goes away while pumping the bulb, and returns when you stop, there is a good chance you"ve isolated the low pressure fuel pump as the culprit. Depending upon the model you may be able to perform a pressure or vacuum check (Yamaha and Mercury tend to recommend the later) or you'll have to disassemble the pump to physically inspect the check valves and diaphragms (your only option on carburetor integrated pumps, but it's not that difficult and can be done on ALL pumps).

Never run a motor without cooling water. Use a test tank, a flush/test device or launch the craft. Also, never run a motor at speed without load, so for tests running over idle speed, make sure the motor is either in a test tank with a test wheel or on a launched craft with the normal propeller installed."
 
Does anyone know what the comp

Does anyone know what the compression should be for a 98 Mercury Mariner 9.9 4 stroke? Thanks in advance. Nels
 
"Definitely sounds like a fuel

"Definitely sounds like a fuel pump problem. I believe you have a mechanical pump that is operated by the camshaft. Is the plunger damaged, maybe not making contact with the cam?"
 
"Update on compression. Upper

"Update on compression. Upper cyl 135# Lower 130# Glad of that. Still no fuel pump in the mail.
I appreciate everyones help so far. Skeeter"
 
GREAT NEWS!!!!!!!!!!!!!!!!

GREAT NEWS!!!!!!!!!!!!!!!! Received pump this morning. Put pump on and took it to the launch. Ran perfect for 45 min in gear at higher rpm than idle. Works perfect. KNOCK ON WOOD! Like to thank everyone that showed an interest in the problem. I hope all the informantion in this thread helps someone else someday. Skeeter
 
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