rev limiter or cavitation??

[j_man_84]

Hey all quick question I have a 2012 40 Yamaha enduro 2 stroke I bought second hand for my 4.2 tinny now the motor starts and idles great, pulls out of the water well and motor sounds great while going but once I get near having the throttle wide open the motor makes a "dah dah dah dah dah" type of sound likes it a rev limiter almost. Now can you get cavitation at full speed or only when getting out of the water??? The sound is like hitting a rev limiter on a car that's the best way I can explain it. My thoughts are that the motor is over revving due to the wrong prop for my boat as the motor was propped for a 4m inflatable firstly.

Im just after peeps thoughts on this before I spend any money and go down the wrong path. Any help would be great.

Jon

[Hole Shot]

I,d say its hitting the limiter,comes in on those motors around 5800,remembering cavitaion is confused with ventilation,two different things,people refer to a cavitation plate on there motor when its actually a ventilation plate.

[scottar]

Try a call to Solas. If anyone knows about what sort of pitch prop you should be running it will be them. Could also be worth getting a "Tiny tach" That way you will know for sure how many revs you are pulling.

[j_man_84]

Try a call to Solas. If anyone knows about what sort of pitch prop you should be running it will be them. Could also be worth getting a "Tiny tach" That way you will know for sure how many revs you are pulling.

yeah have sent them an email tonight will talk with them tomorrow with any luck. Can you get a tiny aftermarket tacho for tiller steer motors and if so where from? cheers

[scottar]

Can't recommend anywhere - just type it into google - stacks available on Evilbay.

[Boofhead03]

I fitted one similar to this:

http://www.ebay.com.au/itm/Hour-Meter-Tach-Tachometer-Boat-Motorcycle-Outboard-Mercury-Yamaha-/171404657088?pt=UK_Motorcycle_Parts_13&hash=item27e88381c0

on my 15hp Yamaha. Works well, you just need to have it somewhere you can read it as the display isn't the biggest. I soldered a 2m cable onto the pickup to make it longer and it still seems to be accurate.

[j_man_84]

yeah picked up a tiny tach and also spoke with solas props who more then helpful have a prop heading out should have by the morning will fit and see how it goes. fingers crossed!