Yamaha maxed out at 4500 rpm's

[jgroh]

1990 yamaha, 90hp full throttle max at 4500 rpm's. just bought, think I was taken by little old man?<br />Thanks

 

[JasonJ]

Re: Yamaha maxed out at 4500 rpm's

Not necessarily. Did you just buy the motor, and install it on a boat you already have? If the motor runs good, and has good compression, then your rpms will be dictated by the prop pitch, and the load it is experiencing. If your setup is heavier than the setup it was originally on, then a different pitch may be in order. Make sure the engine is healthy first, a different prop can't make up for an unhealthy engine.

 

[jgroh]

Re: Yamaha maxed out at 4500 rpm's

Thanks Jason! Bought 17' mako & motor. All original, 1 owner. Compression OK but overheat alarm sounds over 4k rpm's. Under 4k, no problem. Is the 90 not enough to push this boat. 2 people, and access.

 

[quang]

Re: Yamaha maxed out at 4500 rpm's

that might be a problem..<br /><br />make sure that water is getting thru the engine.. it might be cloged hoses, im not an expert, but getting water thru the engine is very important<br /><br />the overheat alarm should never go on! especially if its stock and only a 14 foot pushing 2 people

 

[finnaddict98]

Re: Yamaha maxed out at 4500 rpm's

Had a similar problem with my 200 Johnson....of all things it turned out to the the anti-siphon ball **** where the fuel line exits the fuel tank. The metal ball in the housing fouled and would restrict fuel flow..not enough to hamper rpms..but to make the HOT alarm go off. It took 15 seconds to repair, but hours of BS to find. Give it a shot and let me know how you make out!

 

[jgroh]

Re: Yamaha maxed out at 4500 rpm's

Thanks to all! read another post here an ran vinegar through the motor to clean out the passage ways. Alarm not going off as frequently. Ran 45 miles today and alarm sounded once.