88 force 50 Smokes like a siv and wants to die with hood on

[Bird Chip]

So i bought an old chrysler 15' with a force 50, was running 85 octane with a decent 2 stroke oil at 50:1 ratio. Just trying to get it running in front of my house with the motor in a trash can and it will run fine with the hood off but once its on, it dies out within like 30 seconds due to excessive smoke in my exhaust. Called the local boat shop, they say i should use 91 octane and quicksilver 2 stroke oil, replaced the gas and still no difference. Seems like im running rich but everyone says 50:1 so I'm not sure the problem at this point. Anyone have the same problem or know what might be happening?

 

[sutor623]

Re: 88 force 50 Smokes like a siv and wants to die with hood on

When exhaust gasket fails, it will emit exhaust. The trapped exhaust under the hood enters the carb and chokes the motor out. More than likely you will need to pull the power head and change the exhaust gasket.

 

[Bird Chip]

Re: 88 force 50 Smokes like a siv and wants to die with hood on

Ya i can see quite a bit of exhaust making its way up into the power head....is this a doable job for a novice boats-man that's mechanically inclined?

 

[sutor623]

Re: 88 force 50 Smokes like a siv and wants to die with hood on

Ya i can see quite a bit of exhaust making its way up into the power head....is this a doable job for a novice boats-man that's mechanically inclined?

Well, I am mechanically inclined, and I did my first powerhead gasket last year. It was no biggie, just a bunch of nuts and bolts to me. I even did it without the service manual, but it was only a 9.9hp. I'd definately recommend getting a factory service manual and doing it step by step. And yes it is totally doable (especially when you get a shop estimate and see the price )

 

[sutor623]

Re: 88 force 50 Smokes like a siv and wants to die with hood on

Bird did the owner tell you it had issues, or did he just demo the motor with the cover off? You could try 2 things before you pull the power head. You can try running a heavy seafoam mix through the engine with the cowl off, and let it break down a bunch of carbon. Then run it with the hood back on and see if you have the same issue. You may just be smoking extra heavily because of carboned up rings. Once the engine has a little spring cleaning, there may be a lot less smoke making its way into the carb. Also you can try GENTLY tightening down the powerhead/midsection bolts. Sometimes just a little bit of tightening up can seal up an old gasket. Worth a shot before a powerhead removal.

 

[foodfisher]

Re: 88 force 50 Smokes like a siv and wants to die with hood on

Don't know about the 50hp but my excessive smoke problem was solved by cleaning the fuel recirculation system. '86 125hp.

 

[jerryjerry05]

Re: 88 force 50 Smokes like a siv and wants to die with hood on

If it's choking out the motor with the hood on,it's gonna need a gasket.
Very easy job.
But DO get a manual.