1998 Evinrude 150 low rpm

Optimizing the performance of Boston Whaler boats
Blacklive
Posts: 1
Joined: Sun Mar 13, 2016 6:35 am

1998 Evinrude 150 low rpm

Postby Blacklive » Sun Mar 13, 2016 6:37 am

I have twin 1998 Evinrude 150, I didn't use it for around two years because [there was a] crack on the boat. In that time the pressure was 120 in all cylinders except one was 115, and the RPM was move in max to 5250.

I bought used boat, I sent it to company, they transferred both engines, they did maintenance, cleaned the carburetor, they check the pressure was 110 in all cylinders.

The company told me to put extra oil and move slowly for few hous because engines were stop for long time, I did what they said and I added two liters oil extra on 200 liters (total 6 liters) and moved slowly for 3 hous.

Yesterday I used the boat in normal way, everything was good except the rpm, with full speed the rpm not move higher than 4800 in both engines.

Any idea about the reason?

Thqnks.

Khalid

jimh
Posts: 11672
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
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Re: 1998 Evinrude 150 low rpm

Postby jimh » Sun Mar 13, 2016 2:40 pm

Please give us information on the propellers in use. Give their model name, the pitch, and the diameter.

In any prior testing of the boat with the engines at full-throttle, did you observe a higher engine speed? If so, what was that engine speed?

What is the present boat speed in statute miles per hour when the engines reach 4,800-RPM?

Jefecinco
Posts: 1592
Joined: Fri Oct 09, 2015 6:35 pm
Location: Gulf Shores, AL

Re: 1998 Evinrude 150 low rpm

Postby Jefecinco » Sun Mar 13, 2016 7:21 pm

I thought the 1998 Evinrude 150 was a FICHT engine. Perhaps that was in the US or, more likely, I got it wrong.
Butch