Mercury 9.9 hp.

[OFF SIDE]

Hi Mercury outboard owners.
I recently purchased a merc. 9.9hp for my son and myself to enjoy fishing this year. Although the previous owner indicated the motor worked fine and a short test ride was done. Unfortunately the motor has ended up being nothing short of a dud. The initial trip the motor appeared to work fine , a little hard to start. The next trip the motor wouldn't pull, took the recoil off, fly wheel wasn't moving. Removed plugs to find water in each cylinder.
Sprayed penetrating oil in cylinder fly wheel freed up. The water jacket cover was removed to find the previous owner had reversed the gaskets! Water was pouring into the cylinders, gaskets replaced.
When testing the motor in a bucket, the water gets full of oil from the bottom is this normal? I don't know the motor that well , tell tale is shooting water, exhaust is delivering from leg, is exhaust supposed to come out at the bottom? I can't tell if its coming from the prop or water inlet.
Any comments would be greatly appreciated

 

[NicoPags]

Hi Offside, have you done a pressure test in the cylinders? Do you have a serial number or model #?

 

[tpenfield]

A bit more information on the year (vintage, serial #) of the 9.9 would be helpful.

Assuming it is a 2-stroke model . . .

When running the motor in a bucket , the spent 2-cycle oil will be quite present in the bucket after a bout 10 minutes of run time.

Exhaust will come out of the vents on the shaft at lower RPM's and then out of the prop hub at higher RPM's

Not sure about the gaskets on the 9.9 models. Just make sure you are doing the right thing in swapping them, etc.

It is pretty hard to get water in the cylinders (IMO), unless you store the motor upside down . . .

Again, not much information, so it is hard to determine exactly what is going on . . .

 

[racerone]

If water sat INSIDE the engine it may have damaged the bearings on the crankshaft.----Get this motor running ASAP and hope for the best.

 

[OFF SIDE]

Hi Offside, have you done a pressure test in the cylinders? Do you have a serial number or model #?

Thanks for everyone's replies
A pressure test was done on both cylinders, 120 each.
Looking at other motors in buckets the water isn't as full of exhaust oil, maybe it's just me but there's alot. The gaskets were reversed letting water pour into each cylinder, just confused at how it ran .
Thanks for all suggestions.

 

[NicoPags]

Thanks for everyone's replies
A pressure test was done on both cylinders, 120 each.
Looking at other motors in buckets the water isn't as full of exhaust oil, maybe it's just me but there's alot. The gaskets were reversed letting water pour into each cylinder, just confused at how it ran .
Thanks for all suggestions.

agreed on that, to have One successful trip before this started causing issues and than discovering the water after is wild for sure. Based on your serial you have a 2000 Mercury 9.9HP [M] model 1010201WD. Take a good look through the cylinder block and housing diagrams to ensure proper assembly of the Intake cover, water jacket cover and baffle, and also take a look at the thermostat. All 3 points of entry for water. I am far from a pro or experienced I'm more of a read only user with the odd engagement etc. From there, take a look at the gear housing diagrams to ensure your machine is matching up with the diagrams etc. - it seems you already discovered the initial problem so start there, correct the assembly, and try to recreate your issue first

 

[OFF SIDE]

Thanks everyone for your great advice. I dropped the lower end to find the previous owner had probably replaced the impeller. When reinstalling the lower he had bent over the tube coming from the impeller housing not full engaging on the copper inlet pipe. The housing rubber spout piece was replaced, lower unit installed time to test.
All works great no water in cylinders . There had been 2 mistakes at this point by the previous owner. While running in my test barrel I noticed exhaust smoke coming out just above the lower unit on both sides.
The holes are about the size of a dime. Should these holes be plugged.? I've attached a picture..

 

[OFF SIDE]

Hi outboard owners. Are these holes for exhaust or should they be plugged? Crappies are in hopefully I can get this figured out. Tks.

 

[OFF SIDE]

Can anybody please let me know about these holes? Tks