2 Strokes Yam 85 Overheating.-

[Sea Rider]

Was wondering if any of you guys happen to have in current use this same motor. A close friend bought this motor brand new many moons back, has never been run more than 1/2 to 3/4 throttle as powers a medium light Rib.



Has never been religiously flushed after salt water use. Wanted to test its top end speed with 4 up, guess what, accordingly to a very accurate APP speedometer, the combo only made 38.6 Km/H on flat calm water cond which is extremely lousy and ridiculous.



Time after the Overheating alarm began to screem loudly, motor decreased its wot revs to minimum, backed throttle to idle and the alarm went off after one minute cool down.

Want to make a 150 kilometer raid to a far away island and would be extremely cracy and dangerous to go with such motor that can overheat at any time if the throttle needs to be increased. Know that when the water jackets of any motor used in salt water are completely clogged the only way to find a quick solution to an overheat is to tear both cylinder heads, thermos, temp sensors and install new ones along head gaskets as well. Has anybody experienced the same ? how was the overheat corrected ?

Happy Boating

 

[mike_i]

"Has never been religiously flushed after salt water use" That's not a good way to "take care" of a motor from day one.
Has he replaced the water pump and at least checked if not replace the thermostats? After that run the motor in a tank with water and salt-x, it couldn't hurt, it's a start.

 

[flyingscott]

My dad ran 90 hp (same as the 85 but with oil injection) 38mph on a SS 180 starcraft. I agree do a compression test and and tear it down. What do you mean both heads that motor only has one. You could try salt away in a garbage can and let it run for a couple hrs.

 

[Sea Rider]

Yep, its only a Yam 90 with just one thermo, one cylinder head simple model. Imagine 38.6 Km/H to 36 MPH with same motor. With a medium light rib that motor should fly it to Mars. The motor still works with the factory delivered prop which seems is not doing its homework right. Will recommend the owner to buy an induction tach to check max wot revs the motor revs at as usually loaded.

There's the stupid idea that salt water motors don't need to be flushed with fresh water when returning to terra firme. I know what's going inside as this same example :

https://www.youtube.com/watch?v=xuL3rTtc-VA

Will try to convince the owner to remove the thermo and check the internal condition of the motor, if found severely salted will need to tear the cylinder head, exhaust cover and clean all water jackets to perfection. The motor does not overheats at 1/2 to 3/4 throttle, only at full hammer down for short periods and that's a symptom that the motor is not cooling as it should.

Salt Away will not remove a salt clogged motor, only good for new motors being constantly flushed, this one needs to mechanically scrape and remove all salt layers, crusts from all water passages to cool as when it was brandd new.

Check this interesting video...

https://www.youtube.com/watch?v=8w_o...XqTsgU&index=3

Happy Boating

 

[mike_i]

I've seen the second video before, tried to watch the first but the annoying music was too much.

 

[Sea Rider]

I've seen the second video before, tried to watch the first but the annoying music was too much.

Yep, will need to turm the vid volume to min, many complains about how lous is that music, probably the poster is already a deaf man or in the process to become so. LOL. Check first video when with time, it's very instructive and way to go as there's no other alternative to deeply clean those extremely salted water jackets to near perfection..

Happy Boating