A Bugg's tale of Yamahas and hand grenades

[TheRealAndy]

I personally think it's better for your engine.

So do most people who try and justify the extra expense of higher octane fuels.

[TheRealAndy]

Higher octane fuels will give you some improvement in economy, mostly, apparently, due to slightly higher density I am told, which means more energy per $ because it's sold by volume, not mass. It is a measureable difference. Whether this offsets the extra cost to buy it is the thing to figure.

The cleaning additives are real, and will mean better results due to things not getting gummed/clogged up. Of course, you can buy 91 and add your own additives, or even, just service the motor more often to keep it clean - it's all just a matter of figuring out which costs less per hour of running when you figure in ALL the costs.

I once did the sums on a small hyundai car, and I figured it at least broke even. I have a feeling that, as time drew near to have the injectors cleaned, it was still running better, and that probably made using 95 instead of 91 worthwhile.

There is no difference to economy, this is physics 101. The fuel has the same energy density regardless of octane rating. About the only time it would make a difference is if the engine was knocking and the engine computer retards the ignition to prevent knocking. In this case, the issue is with your engine and has nothing to do with the fuel.

We are hijacking the thread, maybe a new thread is in order if we wish to discuss fuels.

[Dignity]

I also want to know what has happened to the yammies, my outcome was simply a blockage of the top injector, source of blockage unknown.

PS, due to supply of processed fuel from overseas sources you are guaranteed that the lowest the octane rating you are purchasing is what is on the pump, it could be higher the only one you are guaranteed to be what's on the pump is 98, so trying to do milage checks and performance checksis out the window.

[TheRealAndy]

PS, due to supply of processed fuel from overseas sources you are guaranteed that the lowest the octane rating you are purchasing is what is on the pump, it could be higher the only one you are guaranteed to be what's on the pump is 98, so trying to do milage checks and performance checksis out the window.

This is not true at all.

[Dignity]

This is not true at all.

Those in the industry advise otherwise.

[TheRealAndy]

Those in the industry advise otherwise.

Sorry, just re-read your post. Thought you were saying it was possible to have a lower octane rating than what is written on the pump. But yes, you are correct, the octane rating on the pump is the minimum octane rating.

[bugman]

Gents,
Quick update on the F60.
I took it into the mechanic a couple of weeks ago. First diagnosis was instead of a top end failure - it was a gearbox failure. Feeling was I may have hit something and broken some bearings which locked the drive shaft. Maybe the mechanic might give better diagnosis.
Anyway - after further analysis it would seem the gearbox failed from lack of oil - as in no oil.
I don't have an answer as to how that happened - other than it had no oil and it went bang.
I'm now chasing a new gearbox to get her back on the water.
NOT A YAMAHA PROBLEM it would seem.
The 150hp is yet to be looked at.
Brett

[Rip it up]

Bug man that's a semi good result. Only down side is a F60 gearbox is rare as rocking horse shit. As they are the weak link of that range of four strokes.

Best of luck in the search. A new box is sometimes cheaper than you think. $2200


Damo's dodgy boat building repair centre.

[Noelm]

how did the gearbox end up with no oil?? someone did a service and neglected to fill it again, because they do not leak oil out, they leak water in.

[TheRealAndy]

because they do not leak oil out, they leak water in.

Only when they are in the water. I have plenty of oil stains in my garage from the old jono that came with my trailer yacht.

[Noelm]

be pretty rare for a gear box to blow up if its not in the water being used.......

[stevej]

So do most people who try and justify the extra expense of higher octane fuels.

the other issue in a boat with a vented fuel system the highly volatile additives needed to get the higher octane deplete rapidly
alright in a car filled up once a week
just a waste of money in a boat engine

[Smithy]

Buggy, update on the 150?

[bugman]

Smithy,
Shop has kept me busy for the last 10 months. Haven't even been in the cat to look at it. Last time it was growing weeds on the back deck. I'm waiting for my mechanic to open up a spare opportunity to take a look - he wants to sell me Hondas.

[Spaniard_King]

OK OK, bring it down and clog up my workshop!! When?