yamaha 70 hp 2 stroke my 2010 buying advice

[momentum]

im looking at repowering my 4.7m fibreglass half cabin with a yamaha 70 hp 2 stroke my 2010 model
has anyone had any issues with this motor or simillar models?
is there any thing i should watch for in this motor ?
thanks in advance

 

[robert graham]

Re: yamaha 70 hp 2 stroke my 2010 buying advice

Reliable sources say that Yamaha will not import any 2 strokes into USA starting Jan. 1st, 2010, but I'm sure you can find a good new or used 70HP Yamaha 2 stroke still in stock. My experience with the 3 cylinder Yamaha 2 strokes has been excellent, just keep clean, fresh, stabilized fuel, normal maintenance, about as trouble-free outboard motors as you'll find. Good Luck!

 

[triumphrick]

Re: yamaha 70 hp 2 stroke my 2010 buying advice

These (70 &90) IMO are some of Yamahas best motors. The reliability of these 3 cyl motors I feel gave Yamaha credibility and presence in the outboard market back in the early 80's.

The 90 that I owned was used long and hard for almost ten years. The selling dealer gave me two good bits of advice. A mechanic later gave me another.
I was told to always flush the motor, tilt it slightly and remove the fuel hose and always let the carbs run dry. I did. Also he said to mist a light coat of wd 40 over the inside and outside of the motor. I did. He mentioned using Yamaha marine grease and using my finger, put a light coat on the tilt/trim rams, motor, tilt tube and to ALWAYS clean and grease the steering shaft.

So, ten years and about 1500 hrs later I had yet to have a problem of any sort. It got impellers and plugs and lower unit oil every other year. It also was run on synthetic oil, in the gearcase and with the gas. Nothing on that motor ever failed in that time. Towards the end before I sold it, it began to run a litlle hot. The new owner had the cylinder head removed and corrosion in the passages releived. Nowadays I use SaltAway when I flush and help to prevent that.

Good luck, you're about to buy a great motor.

 

[momentum]

Re: yamaha 70 hp 2 stroke my 2010 buying advice

Thanks very much for the advice guys i live in sydney australia so i can still get yamaha,
yeah i cant wait to pick the boat up i should have it in a week or two
happy boating

 

[robert graham]

Re: yamaha 70 hp 2 stroke my 2010 buying advice

Be sure to install a water/fuel separator, use Stabil Marine and Yamaha Ringfree all the time. keep clean, fresh, stabilized fuel all the time, get a motor manual and owner's book and study them to learn preventive maintenance. Good Luck!

 

[momentum]

Re: yamaha 70 hp 2 stroke my 2010 buying advice

Thanks robert
i was planing to get the dealer to install one for me they are even going to water test the boat to iron all the kinks out.
when u say good stabilized fuel what do u mean ?
i use the boat every weekend so fuel dosent get a chance to get stale
and i usuall buy mobile or bp fuel (australian companys)

 

[kaferhaus]

Re: yamaha 70 hp 2 stroke my 2010 buying advice

Thanks robert
i was planing to get the dealer to install one for me they are even going to water test the boat to iron all the kinks out.
when u say good stabilized fuel what do u mean ?
i use the boat every weekend so fuel dosent get a chance to get stale
and i usuall buy mobile or bp fuel (australian companys)

If your boat isn't sitting up for 90 days or more then forget the stabilizer, just a waste of money at that point.

Aus is likely different, but I stay away from BP gas here in Alabama as it's got ethanol in it. We don't have the mandatory ethanol content laws here yet but some brands are adding it anyway.

I've run it (10%) in my truck out of necessity a few times and it's a gas mileage killer... I lose 3-4 mpg running that crap.

 

[momentum]

Re: yamaha 70 hp 2 stroke my 2010 buying advice

hey kaferhaus thank you for clearing that up for me
gas companys are regulated here in aus well so they are sirpose to be the major petrol brands are pretty good they have to tell us if its ethanol they just rip us on the prices but i bet that happens to you guys too
its just the independents you got to watch but i tend to stay away from them.
thank you everyone for your input and advice its been a great help.

 

[robert graham]

Re: yamaha 70 hp 2 stroke my 2010 buying advice

If you're going to run the motor every day, all the time, just like a car, then maybe you get by without the fuel Stabilizer. The Stabil Marine Fuel Stabilizer(Walmart $27/quart) is good insurance against fuel/ethanol/water problems and I would recommend it highly. Talk with your boat dealer for his opinions and then just decide for yourself. My motor is a 1999 90HP 2 stroke Yamaha and the carbs have never been touched, other than regular draining, and the motor runs just like a new one. You'll get all kinds of opinions on fuels and stabilizers,etc., Go to Google: Marine Fuel Additives for additional info. Good Luck with your new motor!

 

[Dunaruna]

Re: yamaha 70 hp 2 stroke my 2010 buying advice

Momentum, I have a similar boat to you and run a 70hp yamaha 2 stroke. It is an ideal fishing package but don't expect skiing performance (a bit slow out of the hole). That being said, For me, it is ideal for chasing snapper in the bay and it will troll all day without smoking or fouling.

As to the fuel issue, I stay away from ethanol and only use large fuel stations that turn over stock regularly. Every few months i will add a stabilizer, the brand i use is called 'fuel set'. Never had a problem.

 

[dbeitz]

Re: yamaha 70 hp 2 stroke my 2010 buying advice

In the US Yamaha are replacing their 90 hp 2-stroke with a 70 hp 4-stroke. The new models should arrive in April/May 2010, I hope, as I have pre-ordered 2 of them. I'm replacing two 85 hp 2-strokes with them, as I'm only using 40% of the fuel on another boat that I have for my dive business, when I switched from a 250 hp 2-stroke to a 200 hp 4-stroke. The 2-strokes are simple to work on, but for my business, I can't go past the fuel economy & the power of the 4-stroke.