Drain line on Mercury 7.5 hp motor

[Lrdrlker]

I've had problems trying to get my little need to shoot water from the telltale. I got it to dribble a bit but then noticed a short 1/8" id hose that runs from the right bottom side to the right top side and is clamped at each end. The schematic says "drain hose". Question...does this circulate water from the water pump to the top of the cylinder? What else would it drain? The hose was badly cracked so I'm replacing it. Should this improve the water pressure?

 

[merc850]

Looks like an oil drain line that moves excess oil up to be burned/lubricate the upper bearing. The only way to get more water flow is to replace the impeller and make sure the water tube is clear.

 

[Lrdrlker]

It was a water circulation line. Water is pumped up from the impeller and enters the motor's front lower water jacket. From there it circulates through then out the lower drain line then up to the top rear water jacket then out the telltale.

 

[Lrdrlker]

I opened the water pump up AGAIN and removed the impeller AGAIN and looked down underneath the volute and saw another piece of rubber sitting there. I removed that then removed the copper suction pipe and saw that it was plugged as well. I took all the rubber pieces out, reassembled everything and , you know what?, it STILL DIDN'T F××KING PUMP!!! I opened up the gear case to check the oil just for shits & giggles and just dirty water came out so...the seals are shot as well! I might run some muriatic acid through the water jackets and let them soak and then flush them out. They're probably corroded from sitting. Looking like a project motor! Cheers

 

[Lrdrlker]

Looking for an old seized outboard around 10 hp to mount a Husqvarna lawnmower engine on. Mower has an adjustable throttle and kill switch...PERFECT for a "lawnboard" project! I'll keep you posted!

 

[racerone]

Well----You seem to know your stuff.----That motor would only have a tell tale hose.----It does NOT have 2 water hoses outside the block !

 

[Lrdrlker]

Thank you for the education. I thought it was a water line because the fluid running through it from bottom to top was fairly clear. Since the original hose was black rubber and was cracked and broken it stands to reason that the fluid level in that closed loop may need topping up. How do I add to this system?

 

[racerone]

Sorry mate-----It is a 2 stroke engine .----You add oil to the gas only.----But some of that oil ends up near the bottom of the block. ----That hose puts it back to the top of the block.------Oil in the gearcase is totally separate from crankcase.-----Time to read some manuals before launching your boat !!