Fast Idle

[Ron Rudolph]

What is the proper idle speed for the 50 HP Yanmar on my 410? Idle speed used to be 800-1000 rpm. On my last outing, idle speed increased to 1500 rpm after warm-up period. Nothing was done to the engine that would have caused this. Any thoughts or suggestions would be appreciated.

 

[Mark Johnson]

Waaay too high....

600 or 700 rpm is more like it. Something must be stuck not allowing it to idle back. Check the throttle linkage to see if something has moved or something is loose.

 

[Dick McKee]

Had the same problem on our 430...

it turned out to be a little corrosion on the end of the cable where the solid part goes into the housing. If I barely pushed on the throtle linkage on the engine it returned to 800 rpm. A little 0000 steel wool on the cable and it was good a new.