9.8hp Merc Issues... Help!

[thundergrey]

Couple years ago I bought a motor off this douche. He said it ran great but didn't want to full a barrell to test as he needed a water delivery and didn't want to waste any. He was a buddies old work friend so I figured he would be straight up. WRONG. The price was right ($500) so I went for it.

The motor had been blown up and new cylinder and block was put in (by him). And he put in a homemade cardboard gasket for the carb but forgot to cut a hole for the exhaust so the thing would only run with me pumping the fuel ball... So this thing never ran and I felt like throwing it through the front window of his truck and "returning" it to him.

Brought it into a shop and $425 later they replaced the gasket and tuned it up, changed the leg oil, and the leg seal or something. It was running so I was happy or at least happier...

Brought it out with fresh fuel, oil and a not rusted out gas tank and cracked fuel line and the dissapointment continued... It is hard to start (like 20 pulls), will not start without a choke and has limited top end power (cant get my 12' aluminum with just me on top of the water). Anyone have any help with this? I believe the motor is early 80's, 9.8hp merc...

[RapStaff]

Is the water circulating through properly?
If not your impeller may be pooched causing poor operation from overheating.

[thundergrey]

its not a constant steady stream (sputters a little) but there seems to be plenty of volume... The water is hot, but looking at the coolant system it flows right in the exhaust flow (weird) so I am not sure if the sputtering is just steam...

[RapStaff]

You need to replace your impeller. Sounds like a fin or two busted off partly obstructing water flow.
PM me and I can walk you through it.
Water flow should be steady and strong.
Not sputtering.
Running the motor hot will rob you of power and eventually pooched the motor.

[thundergrey]

maybe that is why he had to replace the cylinder....

[Kokanee9]

Originally Posted by thundergrey

its not a constant steady stream (sputters a little) but there seems to be plenty of volume... The water is hot, but looking at the coolant system it flows right in the exhaust flow (weird) so I am not sure if the sputtering is just steam...

You should have a steady stream of water coming out of the motor above the waterline somewhere off to the side and rear of the motor. If not, it may be plugged.

Even at idle, there should be a steady stream coming out, and if not, change the impellor.

[Kingfisher]

1978 was the last year that Merc made their 9.8 so it has to be a 78 or older.

I had one that got the coolant system all plugged up and had to back flush it. Other than that it ran fine. Sounds like a fuel pump issue. They are not hard to rebuild or that expensive. I think the kit is about $16 - $20. You can check at http://www.boats.net/ Just enter your serial number and it will tell you the year of your motor and give you a break down of all the parts and how much they are to replace.

Rob

[thundergrey]

Originally Posted by Kingfisher

1978 was the last year that Merc made their 9.8 so it has to be a 78 or older.

I had one that got the coolant system all plugged up and had to back flush it. Other than that it ran fine. Sounds like a fuel pump issue. They are not hard to rebuild or that expensive. I think the kit is about $16 - $20. You can check at http://www.boats.net/ Just enter your serial number and it will tell you the year of your motor and give you a break down of all the parts and how much they are to replace.

Rob

Fuel pump? where is that? Found the impeller.

http://www.boats.net/parts/search/Me...0Up/parts.html

[Stu]

run the motor with the gas can below the motor, then move the gas can above the motor. does the starting, running or performance improve?

[Shmag]

I had a 9.8 merc alot of yrs ago....from what i could remember it used to push water through an exhaust port as well and it was always pretty hot. It didnt have the little quarter inch ****er, but an inch wide by about half inch port right on the rear middle point of the motor. Just below the motor cover but above the water line. Because this port was bigger than the normal quarter inch hole, it always looked like water sputtered

One thing i always had to do was, if you follow the fuel line from tk back to the motor there was a plactic cap that the hose went to on the motor, it had 4 screws on it. Take those 4 screws off and there was a round screen that looked like window screen...beleive they called it a diaghram. Anyways must of had some sediment in the tk as i always had to clean that screen.

Personally, before taking anything apart, i would go back to basic's. Change the plug, pull and clean that screen...and double triple check your fuel mixture, are you 100% sure your running the right mixture....running way too much oil can cause tough starting problems as well as bog your motor. Also common mistake is forgetting to open the vent screw on the tank.

[JohninAB]

If it is hard starting both cold and hot then I have to agree with kingfisher, fuel pump or fuel line issue. Losing prime or weak fuel pump. Trying to remember off the top of my head if there is a vacuum line from the crankcase to the fuel pump, if so check that for leaks as well as it is the crankcase vacuum that usually drives the fuel pump but stand to be corrected on this. Rebuild the fuel pump is an easy task and relatively inexpensive.

[Kingfisher]

Looks like you should get from #20 to #30. That is if they are still available. Looks like lots of those parts are obsolete now. But I bet you can still get a rebuild kit for the fuel pump all at once. Email them and ask. It can't hurt. Go to the "Contact US" on the top right of their page. Then click on "How may we help you" and choose the option "help finding parts". They are very helpful and if the part is available they will know it. You can probably buy the whole damn carb and pump for what the price of all those gaskets will be individually.