Yamaha Hydradrive Problems me 370

craig_c · 10 October 2005, 10:33

Last weekend myself and my father were taking our Redbay to Cambletown until we reached the cock of arran and the engine appeared to have jumped out of gear. The boat instantly stopped and engine revved as if it was in neutral. We then tried to put it back in but it kept revving up. We left it for 5 mins and tried again. It worked!!! for another 30 mins then same again. left it 5 mins and were off again. This happened until we got back to the marina where it started to do it every 5 mins. Uh oh

Having had the boat lifted out my dad and big drew (Andy Gee) drained the oil out of the hydra drive and changed the filter. The Oil was absolutly boggin and thick. The filter showed some metal powder. Had this never been changed since the engine was run in or was this terminal??? Having changed the filter and put it all back together the boat was put back in the water but once again only revved up. The boat has come out the water again so we are llooking for answers

Has anybody encountered this with the hydradrive??

hamadi · 10 October 2005, 10:57

Another hydradrive bearing failure. The drive should be dismantled and all parts checked, most likely bearings to be changed and shimming checked. Several comments are posted on this site.
what kind of boat (weight and cruising RPM)?

hamadi · 10 October 2005, 11:02

The oil strainer should be cleaned and no need to change it. If it clogged again then lots of metal particles are still in the leg. Is the propeller smooth when you turn it clockwise and counterclockwise by hand?

craig_c · 10 October 2005, 12:44

As for the boat details. 1999 redbay stormforce 7.4m with wrapround cruising console and roof. Weighs about 2.2 tons filled with diesel. Cruising rpm is usually 2800 rpm. Were in quite heavy seas at the time averaging around 16-22 knots for 1.5 hours. Engine shows 430 hrs on clock

craig_c · 10 October 2005, 12:53

Boat pic!!

Alan Priddy · 10 October 2005, 14:37

If it is an early unit which it probably is the face of the lower pinion gear will have lost is hardening and the small metal particals will have found thier way into the gearshift main pressure valve. The unit would then have run at low pressure and the face of the forward clutches would have worn down below the oporating spec. The filter is proberbly blocked with a layer of metal on top of a think skin of clutch lining. Looks like a winter rebuild. Contact me if you need advise or a hand.
Alan P

hamadi · 10 October 2005, 17:58

Alan, I wish you were in Tunisia to give me a hand! Frequent failures I experienced with my hydradrives are most likely due to bearing failure. Pinion show some wear most likely a consequence of bearing "collapse". Yamaha Japan confirmed that year 2000 and up lower pinions were changed for harder ones.
Craig, I have two engines with hydradrives and problems occurred at 2800 RPM only in heavy seas (strait of sicily) in a couple of hours.