WAY too much smoke...

[hobojoe]

My ski's have been winterized so I dont think I'm going to be starting them till next spring however, my ski's were "converted" to premix by the previous owner's mechanic. When I ran them, I get HELLA smoke when I'd start them in our out of the water. They ran fine on the water, but when I'd stop and idle, I'd be surrounded by lingering white smoke- to the point where i'm coughing due to the exhaust so I'd have to keep it moving trying to escape the could. It wouldnt clear up after time either. If I'd run them with hose connected on the trailer, so much smoke would be produced it lingered for about 3 of 4 minutes and it literally would smoke up the yard. Kinda embarrassing if there was a breeze and it blows into the neighbors yard/house. I even make sure that neighbors windows are closed before I start them now. I know these older skis smoke on their own but this is just way too excessive compared to someone else's ski that I saw at the dock of the same year range- 94-97.

How would I know that the conversion was done properly?

Is there somewhere to check to see if maybe the oil is dripping somewhere into the motor and causing the extra smoke burn?

Where/how would I clean up the excess oil if I do find something?

What if I wanted to go back to injection?

Previous owner said there were no issues- it was just recommended by his mechanic (probably so he can make an extra buck) to convert to premix due to the age of the skis and "reliability" of injection system (Thats a whooooole different thread)

My mix is 40:1 and I'm using sea-doo oil.

Any input/ direction is much appreciated.

 

[Seadoobuddy]

You can convert back to oil injection. I don't think it's that hard to do.....wait for answers from some one who has done it.

You have lots of smoke because you are burning at 40:1 all the time.
With the injection at idle speed you may be burning at a 100:1 ratio so there is very little smoke. At WOT with injection then you are burning at about 35-40:1 ratio.

SOME oils may smoke less, ie: Amsoil interceptor for one.

I would go back to injection....a lot less hassle, and you use less oil too.

 

[Spimothy Leary]

i'm assuming you checked the obvious.. that it doesn't have both oil in the gas AND the oil pump still attached and running ?
again, seems obvious...but check that first.

usually when you get excessive smoke its due to either too much oil in the gas (bad premix job) or most likely leaky crank seals (but that burns up in a minute or three and doesn't return until the ski sit's in the garage for a few days) generally doesn't keep smoking on the water. your basically saying that even on the water the smoke is way too much ?

going back to injection basically means re installing an oil pump, remove blockoff plate, adding oil tank (or just hooking it back up again)

and I agree with SDB, I use interceptor (and my crank seals are perfect) and mine smokes very little, even after sitting for a week.

 

[hobojoe]

Spimothy,

Yes, smoke is too much even after running for 30 minutes. I'll drop to idle, and then depending on the wind, i'll choke myself out with all the smoke and have to turn into the wind so it blows away from me.

Thats my problem I guess. I dont know what to look for for an original setup with injection. I know that the oil tank is still there and it is filled with oil. The previous owner said he kept oil in there so that the low oil "alarm" doesnt trigger. Common sense tells me there'd be a stoppage of flow from the oil tank if it was converted but just having basic combustion knowledge that lots of smoke means something other than fuel is burning so in this case, I'm thinking its the conversion.

 

[LouDoo]

Since you are running premix you can expect more smoke at idle. The oil injection system is variable rate so you are running approximately 40:1 at WOT and considerably less ratio at idle, probably 70:1 or more.

The white smoke concerns me, white smoke usually means steam, which means water in the engine where there shouldn't be in the engine.

You also could be getting excessive oil past the crank seals, but that should clear up after a few minutes of riding.

Lou

 

[Spimothy Leary]

can you see an oil pump connected ?

again, it seems that normally the answer should be NO, you don't see it but I have seen it before where a guy was premixing and still had the oil pump installed and functioning, so basically he was pumping double oil in there..just trying to eliminate something obvius.

 

[hobojoe]

Lou,

Definitely not steam, it doesnt evaporate or disappear quickly, it lingers, and drifts like smoke does.

Looks like i'm gonna have to make a trip to storage facility and bring them back out of hibernation to see what I see.

 

[SabrToothSqrl]

What oil are you using? Anything other than the XPS2 seems to smoke a lot more than xps does.

I'd go back to oil injection... That engine has a ROtary valve that needs an oil bath anyway.

 

[racerxxx]

40:1 is the correct ratio. My Speedster runs pre-mix, I use XPS-II and I mix it 40:1 and have very little smoke what so ever. Even idling for 5-10 minutes through a no wake zone. You can switch back to injection like others have pointed out, BUT make sure you have ALL the components to make it work. On your 720's the pump is under the carbs on the rotary valve cover and there is a gear that drives it, verify the gear is in there. You will save oil by running the injection.

My question is, are you adding oil to the oil tank too so the oil alarm won't go on? If so, perhaps it wasn't converted properly and you running injection AND pre-mix resulting in too much oil causing the smoke. And if it is converted properly and your adding oil to the tank then perhaps the inner crank seals are bad and your consuming the oil and burning it.

You can find what it looks like here on Ebay
http://www.ebay.com/sch/i.html?_nkw=seadoo+oil+pump+720+&_trksid=p5197.c0.m627

 

[hobojoe]

I havent added any oil to the oil tank itself. I'd say its 3/4 full. Also total run time for me is probably 3-4 hours each this season as I was getting to know the skis and didnt quite trust them yet to put family/friends on them. Thats why I say "conversion" because I dont truly know if it was done correctly or not. I'll need to inspect.

I'm using the sea-doo oil that was given to me by the previous owner. I got 2 bottles. I do remember one of them saying mineral oil- I thought it was odd, but it was Sea-Doo branded and thats what he told me to use. I think the other is synthetic. I'm going to have to go back and check.

 

[racerxxx]

Mineral is what should be used on the 720's, the 787's and 951's use the Synthetic.