High RPM at working temp

[franky2012]

Hi, I have a Yamaha F70 2012 4-stroke. It works fine but when it reaches its working temperature and I put it on neutral, the RPM stays at 2,000. I just need to turn it off and start it again and "youpi!" the RPM is in the 750-800 range. At the morning start-up, everything's fine too. This problem is encounter only after a run, I put it to neutral and want to enjoy the scenery and the engine is running and running fast (2,000 rpm)... It's annoying and I'm afraid to break something everytime I need to engage in drive or reverse (I can hear a poock and the boat swing a bit). Don't know if I can do something about it??
Thank you for your answer!
Francois.

[rodbolt17]

could be as simple as a mis-adjusted throttle cable or a bad ISC valve.
DO NOT shift gears at 2000 RPM.
DO take it to an autherized factory service center.
use the dealer locator function on the yamaha marine web site to find a dealership with a master tech.

[franky2012]

Thank you for your prompt answer!
How can we explain that its come back to a normal rpm if I turn it off and star it right away???

[99yam40]

ISC resets at shutdown maybe

[franky2012]

Make sense... I'll check the ISC valve.
Thank you both for your help!!

[franky2012]

I found the ISC valve but, honestly, couldn't find anything wrong (don't know what to check either!)... BUT... my water separator on the engine was really FULL... I empty it. Could it be the cause of the high RPM??
Thank you guys and have a nice day!
Francois.

[rodbolt17]

no
water in the fuel wont set a high idle.
may set a no idle if it gets in the vapor seperator.
a 2012 should still be under warrenty.
get it fixed as high speed shifting may not be covered and the gear case is just over 2000 dollars.
use the yamaha marine website.
it has a dealer locator function.
click on dealerships with service.
find one that employs a master tech.
5 star is a compleated vidieo course.
in absense of a master tech look on the wall.
look for school certification for at least 4 stroke systems,fuel systems and electricle system certifications.

[franky2012]

Thank you Rodbolt for the advice. We have a dealer here but they don't know how to install a rpm gauge (had to do it myself...). I don't think they hire a master tech!!! The nearest is at 2h30 by car... I will go to my dealer for the maintenance before winter and I will ask them to check that problem. If they can't resolve it, next spring, i'll drive to the next dealer!!! No choice!!!
Thank you and have a nice weekend!
Francois.

[rodbolt17]

shifting at 2000 RPM WILL DESTRORY a gearcase and MAY not be covered under warrenty.
you can also call the yamaha consumer number and disscuss options.

[franky2012]

I'll stop shifting at high RPM. I did know that it could dommage something but I didn't know it could be that bad!! I'll make sure my dealer know the problem and fix it... That way, if something bad happen to my gearcase, they will have a working order in their files about that problem... I hope they will fix it right away.
Thanks and have a nice weekend!
Francois.