Sudden vibration and loss of drive

traveller022 · Post by **traveller022** » Sun Jun 11, 2006 11:52 pm

My Seagull Forty minus of circa 1960 vintage started first pull as usual on Saturday but after about 15 mins running started to vibrate and make a horrible mechanical noise as if the engine bearings had failed. It kept running and the vibration got steadily less although the noise remained and apart from this noise , it did seem to be running ok although there was hardly any drive to the prop even at full throttle and it struggled to move my dinghy at all. Could it be a breakage in the transmission or does it sound like a terminal engine failure? Any advice would be appreciated as it's far too young to die!
PS: I have been running it on 25:1 but am not sure if it has been converted to do this.

Post by **charlesp** » Mon Jun 12, 2006 10:54 am

Yes you're right it's too young to die; the thing is just barely run in.

At first glance at your message it's unlikely that bearings in the power head have gone - I'm sure you have a drive train problem.

Rock the flywheel around - see if you can detect any slop in the crank. Does the prop turn? Is the spring broken?

An intact spring and no apparent slop mean you'll have to look closer at the driveshaft - maybe it's rusted through. And the gearbox, maybe drive has been lost there.

Whereabouts in the country are you?

Fear not. I work on the principle that no Seagull is actually ever dead.

james · Post by **james** » Tue Jun 13, 2006 1:26 pm

this sounds exactly like the problem i had with my 40+ a few weeks ago. the vibration was the small pinion gear in the gearbox ripping itself to peices, leading to a loss of drive.

have you been checking the oil in the gearbox reguarly?

if this is the case its a pig of a job to split the gearbox from the leg in order to replace the pinion, i have been applying heat and penetrating oil for 3 weeks now and hitting the screws with an impact driver and still no result! this weekend i am going to shopw no mercy

and get out the welder or put the whole bottom leg in a forge in a last ditch attempt to release that stubborn final screw.

traveller022 · Post by **traveller022** » Tue Jun 13, 2006 11:42 pm

Thanks for taking the time to reply, I found both responses very helpful. I think i am going to have to check the transmission and hope it will be a simple fault to rectify. PS I live in Morecambe and i changed the transmission oil and gasket in the winter.