New boat owner. Yamaha 89-90 85 hp 2stk

[stmhotel]

I just bout a 89 starcraft 16ft ski boat with a 89 yamaha two stroke outboard at 85 hp. My insurance company says it might be a 90 they did not see an 89 model made at that horsepower. What I wanted to know is what I need to look out for in a yamaha motor good or bad and maybe someone who has had a motor just like this. I am a new boat owner and I want to make sure I take care of it properly from the very begining. Any help for a new boat owner would be great.<br />Thanks,<br />stmhotel

 

[jasell]

Re: New boat owner. Yamaha 89-90 85 hp 2stk

Hi,<br /><br />The 85 hp is a "economy"-version. It has no oil injection and a little bit less electronic.<br /><br />So you have to mix the fuel, 1% tcw-3 oil.<br />You have a manual choke that you have to activate until it fires for the first time, then you can release it.<br /><br />Make sure is clean under the hood and change the pluggs (NGK BR8HS-10, .9 - 1 mm gap).<br />Also change the oil in the lower gear. Look at the old oil, is milky? (Then you might want to service it, it leaks water)<br />Do you have a lot of metal scrap on the lower oil plug (has a magnet on it to capture debris). If there is a lot of debris you migh again want to service the gear.)<br /><br />If the condition is unknown you better replace the impeller for cooling water, you don't want it to fail when you are out on the see.<br /><br />Check the hydraulic trim, does the engin stay up or does it slowly (a week) lower it self. Add hydraulic oil. Also look for rust on the trim pump cover.<br /><br />Of course you have to get a service manual, like the one for Clymer, it will not always refer to your 85 hp since it not so common. but it is a 3 cylinder but I'm not sure if it closer to the 80 or 90 hp.<br /><br />Myself I have 90 hp (-00) and my father inlaw have a 85 hp (-94).<br /><br />Hope this gets you started.

 

[bossee]

Re: New boat owner. Yamaha 89-90 85 hp 2stk

1% oil in gasoline (100:1) seems a little to low oil in my opinion. I would use 2% oil (50:1).<br />Preferebaly 2-stroke marine biodegradable oil like:<br />Castrol Biolube 100<br />Mobil 1 Outboard<br />Quaker State Synquest Outboard & Snowmobile<br />Shell Nautilus Biodegradable Outboard Oil TV W3 <br />Texaco Motex Bio Outboard<br />Valvoline Syn Power Outboard 2T

 

[JB]

Re: New boat owner. Yamaha 89-90 85 hp 2stk

2% would give you the recommended 50:1 ratio.<br /><br />Any TC-W3 rated outboard oil should serve well.<br /><br />Good luck.

 

[jasell]

Re: New boat owner. Yamaha 89-90 85 hp 2stk

Isn't Yamaha supposed use 100:1 in oppsite to other outbords that run on 50:1?<br /><br />I can see the benefit of a richer mix since we are talking about a machine with a couple of years on it (-89).

 

[ivar]

Re: New boat owner. Yamaha 89-90 85 hp 2stk

I'm sure the yamaha triples without oil inj. are using 50:1.

 

[rodbolt]

Re: New boat owner. Yamaha 89-90 85 hp 2stk

most anything over 30 hp is 50/1. I reccomend even the tiny mites to bump up to 50/1 for storage protection. nothing like getting your baby out of the closet after it sat a year to find it rusted inside.