1995 Yamaha 90 Questions

[Waterrazor]

I'm going to go look at a 95 yamaha 90HP. I was wonering what to look for since this is my first outboard! It has a self mixxing tank atached and it is not very fadded. It is on a boat and I was able to turn the key on and the console had a honda hour meter that read 690 hrs. That sound like alot for a 1995 engine? I'm going back on monday for a water trial and the owner said he would check the comp. in front of me. What should the comp. be? Any info. or advice would be greatly appreciated!

 

[12Footer]

Re: 1995 Yamaha 90 Questions

Yes, that's a lot of hours, but hours are not as important as how well the engine has been maintained.<br />On the compression test, numbers should be equal on all cylinders, or within 10% of each other,regardless whether the baseline reading is 90 or 120 PSI...As long as they read close to each other.

 

[Waterrazor]

Re: 1995 Yamaha 90 Questions

I would just like an opinion on what numbers were healthy for this engine!<br />Anyone?<br />Thanks

 

[John from Madison CT]

Re: 1995 Yamaha 90 Questions

Waterrazor,<br /><br /> I have 2 Yamaha 90hp motors. Both motors have compression from 115-120 psi.<br /><br /> I hope that helps.<br /><br />John

 

[Waterrazor]

Re: 1995 Yamaha 90 Questions

Msdison, I had a johnson that used to read 180-185. My jetski has 150-155. 115-120 sound kind of low?<br />Is that the norm for these engines? How many hours do they have and what year are they?

 

[butlp]

Re: 1995 Yamaha 90 Questions

Waterrazor<br />I just went through the factory service manual and it does not give a recommended compression. I was always told that as long as they were above 100 psi and within 10% all is well.

 

[Waterrazor]

Re: 1995 Yamaha 90 Questions

Canadian, thanks for looking. I'll be going to see it today and I'll let you know how it goes!

 

[terryc]

Re: 1995 Yamaha 90 Questions

If you are worrying about hours, i have a 1997 Yamaha 70HP with 1,680 Hrs and still going strong, others have told me you can get even 3,000 hrs depending on how the motor is cared for. I only wish mine was a 90 hp,<br />These motors seem to have a good reputation.