Up In Smoke

[JonM81]

Hey guys... I had my 1979 VIP Bass Boat w/ 80HP 800 Murcury engine out night fishing last night... When returning to the doc I noticed a good amount of smoke coming from the motor right under the motor where the lower unit starts... Could this be the drive shaft in this area? I could not see anything wrong from taking the motor housing off the top. I have been greasing all the points during the summer so I'm not sure what I have goin on here... Any advice appreciated.

 

[mellowyellow]

Re: Up In Smoke

when was the last time you put in a new impeller?<br />I would pull the spark plugs and look for signs<br />of melted metal (burnt piston) to start.<br />good luck,<br />M.Y.

 

[JonM81]

Re: Up In Smoke

to my knowledge the boat has never had a new impeller put in. I pulled the spark plugs and cleaned them up yesterday befor we went out and they looked decent, but I will check them again. How difficult is it getting to and swapping out the impeller? Thanks for all your help.

 

[JonM81]

Re: Up In Smoke

OK... Here's an update... The plugs are just as I left them yesterday good and clean. I did hook the motor up to the water hose and rabbit ears to see if I could see just where the smoke was comin from... I did not see it smoking from anywhere exept the prop... I did throttle it up a little but never got to put it in drive.... It seem to be pumping water out just fine. I dont know if that narrows my problem to the driveshaft or something similar having to be in gear to see... Hope this narrows it down for ya a little as well... Thanks again!!

 

[JonM81]

Re: Up In Smoke

OK... Also tested it in fwd gear... no problems at all now... I guess I'll drag it back up to the lake soon and see what happens...

 

[roscoe]

Re: Up In Smoke

The driveshaft is always turning when the engine is running. Night fishing means cooler air temps, cooler air temps means more steam will form, and it will be visible when any light hits it. I think you created your own fog.<br /><br />Impellers are one of the most talked about subjects on this board. Need a manual, an impeller or complete waterpump kit, some basic tools/wrenchs, and some time to do it. Most recommend it be changed every 1 to 3 years.

 

[BF]

Re: Up In Smoke

hooking the motor up on muffs on a hose isn't the same as making the water pump work. The water pressure from the hose might make everything look OK (water coming out the tell-tale and exhaust), but your water pump could still be shot. Your motor should spit water and exhaust out the "relief" holes at the back of the leg when it's idling in water (the exhaust opening down by the prop has 15" or so of water giving it backpressure). On the hose it'll look different (no backpressure). <br /><br />It could just be that you noticed the exhaust more at night, or it could be that the water pump isn't working right. Either way I'd change the impeller if it hasn't been done lately!! My 150 (with good impeller) is a fairly smokey motor, particularly at idle. Once the rpm's come up, the exhaust is mixed with more water and the smoke isn't noticable.<br /><br />Brent