'88 DT75 water cooling help

[bassmasta]

My DT75 was working fine up until I did a gear oil change. (yes I did a proper flush and i filled it properly). I used quicksilver gear oil.

I'm now having a problem with my water flow and cooling.

I was out on the water and the cooling was fine. Did a gear oil change and now the water intake isn't working as good. I've had the boat for over a year with no problems. The water ways are not clogged. I can pump compressed air and nothing is clogged. However when I start the engine no water is being spit out at the **** holes. What I can do is remove the thermostat housing cap (btw, I'm not running a thermostat for this test), put water through there, close it off, then run the motor and then water flows without any issue. I then drain it, then attempt the same test and nothing pisses out. I tested the thermostat and its fine, so even with the thermostat in or out it, the water flows as long as I feed water through the housing first at the top.

Any one have any ideas? I don't want to start tearing the bottom end just yet.

 

[James R]

Re: '88 DT75 water cooling help

Are you attempting to run on muffs.
Some Suzuki's don't like that. Put the lower in a tub or lake up to a depth that the cavitation plate is covered then try it.

 

[bassmasta]

Re: '88 DT75 water cooling help

Yes, mine is one of those suzuki's that don't like muffs. I've always had to use a tub. So yes I'm using the tub to test and water is a good 3-4" above the plate

 

[James R]

Re: '88 DT75 water cooling help

Water pump and or tube seal. Blocked water intake. Most likely a bad impeller.
If the plate and or the housing is scored it will need replacing. The pumps don't work at all well with scoring.

 

[bassmasta]

Re: '88 DT75 water cooling help

Ok, I think it was just a partial block in the water intake because now it works fine. However, I think I have a bigger problem. In my tub there is now a whole crap load of oil, which looks to be gear oil, after running my motor. I guess I'll have to drop the bottom end and see where this oil is leaking from.

Anyone have any ideas/help for me? This will be my first time dropping it.

 

[James R]

Re: '88 DT75 water cooling help

Is it a dirty color or are you seeing rainbow colors on the water. The dirty color is probably unburnt oil from the exhaust.Quite normal. Rainbow colors denote regular oil which could come from the lower unit. Failure to replace the fill and level plug seals or failure to tighten the plugs will give you leak. Suzuki lowers are generally very good in staying sealed.

 

[bassmasta]

Re: '88 DT75 water cooling help

It's a dirty oil. Dirty Like I would see after doing my Jeep's oil change. I've never seen my Suzuki spit out this dirty oil before in the tub when testing it out.

 

[99yam40]

Re: '88 DT75 water cooling help

Check the oil level and for water in the power unit to start with.
you can tell Lower unit oil by the smell.
Could be just unburned 2 stroke oil and gas with carbon in the water you are seeing

 

[bassmasta]

Re: '88 DT75 water cooling help

Oil Levels are good.

Is having unburnt oil ok? am I running to Lean/Rich? If so, how do I go about solving this issue? I'm assuming I should be able to readjust the timing to fix this Lean/Rich issue.

As a note, I'm still using the Oil Injection unit. Unlike others I am not premixing.