Dark oily leak from 84 rude 115hp

[goastrider]

Hello, everyone, I have several concerns for the yoda's out here! I just bought a 17.5 smokercraft with a 1984 rude 115. I am noticing a thick blackish oily goo running down from the bottom of the top motor casing when the engine is put in a vertica position after pulling it out of the water. The engine seems to run fine though there seems to be some vibration at high speed, changed prop no change. <br /><br />With engine cover off I do not see any source of this goo. The plugs are slightly fouled with oil and light carbon. I have drained the main tank and am using 50:1, I also have run it on a new 6 gal tank with 50:1 and get the same problem. Total amount of goo would be a tsp or two. The area around the heads seem clean and the air intake on the carbs are some what clean, there is a fine coating of clean oil each time i run her. ( some one told me it's a stuck reed valve ) Could this be the source of both oily messes.<br /><br />I am also getting a leak from the tilt hydrolic lines each time i take her out. I have replaced the two bottom orings and it has slowed down but the main leak seems to be the fitting on the bottom of resouivor ( can't get to it with out pulling whole tilt/trim unit out.<br /><br />aside from these I am very happy with my old rude. I will need to get some smart tabs though as she porpious pretty bad above 25 and drops off of plane at 20.<br /><br />I thank all of you in advance for the work your brain cells will do in helping this confused boater.<br /><br />Boat is operated at a lake at 3,600' if that helps or not.<br /><br />It's long but I hope i have given enough info to get some ideas.<br /><br />Thanks again

 

[11craigt]

Re: Dark oily leak from 84 rude 115hp

I have an 83' and get this too. I believe it to be what is left over-unburnt fuel in the exhaust...Black and gooey and runs down the the back of the lower unit. Porbably shouldn't be, but lets see if somebody says its' a seal gone bad?

 

[Goodoleboy]

Re: Dark oily leak from 84 rude 115hp

It is unburned fuel mix. I would suspect your running abit to rich. <br /><br />But thats certinaly better than running lean. A little bit of unburned fuel mix is normal for a two stroke. I wouldnt be conscerned about it.<br /><br />Good luck!

 

[steamboatwilly]

Re: Dark oily leak from 84 rude 115hp

Good evening Goastrider,,, On my 150-vro,I added extra oil in the tank(mistake)and it would really get oily around the intake,still does without extra oil.On my 1995-25,it trolls 99.9%.Never touch throttle,I mix 25-1.When it gets home the black goo pours out.I would say Anchorthis and Goodoleboy are right on it.

 

[steamboatwilly]

Re: Dark oily leak from 84 rude 115hp

Sorry, I forgot to add,when I double-oiled the 150,the oil ran out of carbs.and down the housing and ran off the prop..I thought the tilt-trim had sprung a leak.

 

[goastrider]

Re: Dark oily leak from 84 rude 115hp

Thanks for the insites on the oily goo. My question now would be should i rebuild the carbs?

 

[11craigt]

Re: Dark oily leak from 84 rude 115hp

I wouldn't think you'd have to worry about the carbs, seems to be running smooth, no hesitation right? Are you sure the prop/new prop is the recommended prop for the engine....you said vibrations? Maybe that is a problem for you?

 

[goastrider]

Re: Dark oily leak from 84 rude 115hp

Engine runs fairly smooth, a little hesatation from 3000 to 4000 not much. It was running a lot ruffer till I ran a can of sea foam through it. Looking thru spark plug holes the pistons and part of cylinders i can see look clean enough. I noticed that when I got home and flushed engine I got just a little streak of the black goo after about 10 min at idle. I gunk engine and did again same results. I can not locate the source of goo. it just starts draining from bottom of the engine cover down shaft between shaft and bracket.<br /><br />The prop that came with boat was a 17" and had a lot of cavatation burns on it and chipped edges. Took awhile to come up on plane. I bought the Hustler interchange system with a 17" and 15" prop. The old 17" WOT was 4800. the new 17" was the same, still long time to plane. the 15" WOT is 5300. The Hustler props just seem to "rumble or vibrate" a little more than the old damaged prop. weird I just can't really put it in words it's more of a feeling the boat gives me. Wife and kid do not notice a differance except that the 15" is much quicker in getting on plane. Boat still comes off plane below 4000 with either pitch.

 

[11craigt]

Re: Dark oily leak from 84 rude 115hp

How your motor is mounted (position wise - high vs. low on the transem) I would imagine it is something to look at and determine?

 

[G DANE]

Re: Dark oily leak from 84 rude 115hp

The small amount of oil in intake silencer is normal, dont worry about that. A sticking or damaged reed will cause severe blowback thru intake and silencer when iddling and miss on one cylinder. You will notice. Unless your boat is very heavy ( i dont know your exact type, isnt common here in Denmark ) you should be able to turn a 17" or even 19" pitch up to recommended RPM. Something indicates your motor isnt performing its best. Try to put weight and boat measures in a prop calculator, and see what is recommended pitch. ( your gear ratio is 2:1 )If you have troubles turning that, something isnt set up right. Or compare speed to estimated ((horsepower/weight)**0.5) * 200 = mph deep V is = 180 factor<br /><br />If you can't read that it's divide horsepower by weight, take the square-root of that quantity, then multiply result by 200. The weight's in pounds, and the multiplier factor is 180 for deep v-hulls, 220 for flat-bottom boats like jon boats, and 200 for 'average' hulls.

 

[goastrider]

Re: Dark oily leak from 84 rude 115hp

The motor is mounted flush with top of transem. Antivent plate is about 2" below hull. Has two holes above current bolts.<br /><br />The speed calc is 39 to 42 MPH. empty weight and est.. full weight. Speed with 17" is about 38mph and 15" about 30mph. I am sure that the motor is not putting out 115hp due to age, wear and elevation of 3600'. Hull has some minor dings in bottom. Outflow from back is even on both sides and pretty smooth. When I got boat the trim bar was in top notch, caused very high bow ride so I moved it down to bottom and adjust trim with speed. Onboard fuel tank is in rear and holds about 180 lbs of fuel. 27 us gal. boat is very rear heavy, I tried putting 3 people in front and it did plane quicker without the bow rise, very dangerious thing to do though with this boat, flat fishing bow.<br /><br />Is this a good case for tabs to help? I would like to plane at a slower speed and wider rpm range.

 

[Solittle]

Re: Dark oily leak from 84 rude 115hp

Don't go to the tabs just yet. First move the engine up so that the cavitation plate is even or a bit above the bottom of the hull. Run it at that setting and post back with the rpms at WOT. RPMs and performance should pick up.<br /><br />Dhadley is one of our resident performance set-up experts. Do a search on his name.