what RPMs should I have at full throtlle in 150hp

[ultrasport]

Hey guys Ive just recently purchased a 2004 2120 with 150 yamaha 2 stroke. At full throttle im only running 4200 rpm. A fellow member believes I should be getting more RPMs outta that motor. Is that true? If so maybe I have the wrong prop? The previous owner told me his original prop was stolen off the boat. Current prop, dont know the pitch but is in good shape. Thanks guys.

 

[Megabyte]

This site says 5000 to 6000 rpm.
http://www.piranha.com/motor_specs.php?id=7168

At 4200 rpm, you are WAY over propped.
After the original prop was stolen :roll: they slapped on whatever they could find (and it isn't right).

 

[Ranger Tim]

Start cruising the auction sites and find a replacement. Not sure about which fit the two stroke 150 but there are props that turn up frequently can be had for significant discount. I bought my back up 13-3/4 X 17 black steel for less than $100 BNIB. Had to wait a few moths for it but worth it.

 

[Luv2fish]

I have a 2005 that I just bought. I was in the same place (4200 max) and purchased a new prop. I don't have the specifics with me right now but it put my max RPM up to 5200. I know that the Yamaha tech that surveyed the motor for me prior to purchase said the motor had never been over 5000 before. He also said that it needed to be run at that speed sometimes.

There are numerous posts here on your setup. I'll be out this weekend and I'll grab my prop information for you. I might have some of the paperwork at the house also.

I noticed a major difference with getting on plane with my new prop. Of course this is all dependent upon how many people you have in the boat, fuel level and gear.

 

[ultrasport]

ThANKKS GUYS YEA LUVTOFISH IF YOU CAN GET ME THE PROP INFO YOU GOT THAT WOULD BE GREAT SO i CAN PURCHASE A NEW ONE.

 

[Bryan 2530]

If you get all that beer off the boat you main gain 1000 rpm or so. LOL

 

[Luv2fish]

Thunderstorms deterred the wife so I didn't get to the boat. We'll be there tomorrow and I'll get you the information. If you PM me your email I'll email it to you when I get to the boat (a bit quicker).

 

[Luv2fish]

Here is my prop information: 14 1⁄2 15 Reliance 68F-45970-00-00

Good luck

 

[ultrasport]

Thanks luv2 ish got the 14.5 x15 prop but got a solas instead of the reliance. Previous prop was something like 13x17. Its like a different boat gets right up on plane and has power. But still only running 4700 rpm at wot but sooo much better thanks for info.