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Racinbob

High octane gasoline

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Racinbob

This isn't about a motor on a Wheel Horse but it does apply. I recently purchased a new Caterpillar generator with a 420cc motor. I prefer to run ethanol free fuel and the most convenient  station to get it only has 91 octane. I figured the only thing that will hurt is my wallet a bit. I fill the generator tank and proceed to open the user manual. It specifically states to use fuel with an octane rating under 90. I've always figured that high octane fuel wouldn't hurt a thing in any motor and at the most was just a waste of money if not needed. The way Caterpillar stated things I became curious as to why so I hit the internet again. The results were mostly the same as my thoughts have been forever but there were some that said otherwise. The no-no's were mostly about some overheating around the valves. Now, I'm fully confident that no harm will come especially since 91 isn't a real high octane and, to be quite honest, I'm still with my original train of thought but the fact that Caterpillar stated that in a manner that you shouldn't run 90+ octane.

 

With the vast amount of knowledge the members on this site have I thought it would be interesting to hear some of your thoughts on this. :)

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WHX??

What flavor of engine is in it Bob? I wouldn't think it or the whole genny is made by Cat. Just their brand on it? Seems to be the thing to do theses days. What does the OM say about running ethanol laced gas in it? It would be ok to run the corn gas in it if you were going to burn the whole tank but most gennys sit and we know what corn fuel does to rubber. I would be tempted to put some of that new fangled canned fuel in it for long term storage. They have it for four stokes now and has an ungodly shelf life but might be 92+ octane. They don't exactly give it away but if it's worth it?  I use it in all my 2 strokes and does make a difference. Especially when saws and weed wackers sit for months.

https://www.tractorsupply.com/tsc/product/trufuel-4-cycle-fuel-1-gal-1126599?cm_mmc=feed-_-GoogleShopping-_-Product-_-1126599&gclid=CjwKCAjw2dvWBRBvEiwADllhn_HMyRRbQXtiTgOjhQ63DDRvtRVVU8urZ5frLCJ5SxhMVNWRgu4rcRoCMJ0QAvD_BwE

Just says high octane.

37 minutes ago, Racinbob said:

recently purchased a new Caterpillar generator with a 420cc motor

How do we know this to be true if there are no :text-coolphotos: ?!?!?? You know you wouldn't have this problem if you wouldn't have sold your :wh: genny to Tom!

Edited by WHX16
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ACman

From all my years of reading my HotRod/CarCraft magazines all stated that burning high octane fuel will only help you so much . The engine will only produce so much horse power with the combination of parts put into your build and the extra money you spent on the higher octane just goes out the tail pipe. Using race fuel in a vehicle that doesn’t get used much helps as the fuel doesn’t go bad for years. On a small engine I really don’t know the effect it’ll have on it . :confusion-shrug: Bob go buy a gallon of 110 and put it in one of your tractors and tell us what happens besides that wonderful aroma of race fuel coming out the exhaust. :auto-layrubber:

Edited by ACman
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oldlineman

I am no expert but I have always heard that high octane gas runnes cooler in a air cooled engine. I think it is less volatile than lower octane gas.

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Racinbob

Ya made me go out in the cold and take a picture Jim. :kbutt:

 

5ad754ec4025d_CatGenerator.thumb.JPG.c5b0cf8578888a2a8a7f619eb2046d1c.JPG

 

You're right about selling the :wh: generator but I wanted to get something my wife could handle. An old lady like her isn't about to go swapping attachments when em power is needed.:hide: I suppose I could have dedicated a tractor to the generator but I'd hate to do that for an attachment that used so little.

No, it's not made by Caterpillar but like the vast majority it just branded Cat. I went for the features and sized it to do everything we need in the house. Plus the warranty was better than most.

None of that new fangled fuel in this thing. That would be $183.92 per tank. I could justify it for some things though.

It looks like we have 3 that agree with my thoughts that it won't hurt a thing. @oldlineman there were mixed thoughts on the heat thing as well. I think I need to quit researching things so much. :wacko: Again guys, I just started this to hear the thoughts of all the smart guys here. So far I've heard 2 (pay attention Jim, you might learn something :teasing-neener:). There's another station around here that has lower octane booze free fuel and I'll start going there. Not cuz I'm worried about the 91 but it's probably cheaper.:)

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1940willys

I too have switched to the High Octane stuff,they said it's non ethanol and stores longer. Get it at our local Kwik Fill station Made in the U.S.A. It started at 92 and now I see it's 90 octane. I use it in two and four  cycle stuff: Macs, Tecumsh, Kolhers. Hot Rod stuff normally asperated  and supercharged Big blocks small blocks Fords and Chevys. I have heard that Higher octane fuel burns slower in the combustion chamber I'm all for made in the USA!

Edited by 1940willys
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lynnmor

I doubt that octane rating makes any difference in that Universal Chinese Generator.

 

While I hate ethanol as much as anyone, the last two tanks of ethanol free that I put in my motorcycle caused it to run poorly till it is thoroughly warmed up.  My guess is that it is not seasonally adjusted like other gasoline and doesn’t vaporize well in cold temperatures.

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WHX??

Interesting Lynn, what kind od motorcycle/engine, fuel injected?

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oldlineman

My son has a 2015 Subaru WRX that is turbocharged and he has to run high octane gas because with the turbo it makes more heat and the lower octane runs too hot and can cause internial heat related problems, like preignition and burnt valves and pistons. The higher octane runs cooler and will not preignite. Thats what the book says anyhow.:rolleyes:

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WHX??
2 minutes ago, oldlineman said:

will not preignite

True which is critical in high compression motors. Not so in our low compression :wh: Kohlers that's why I'm not afraid to run corn fuel in tractors that are not going to set as we know what it does to everything rubber in the fuel lines when they do set.  

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JoeM

I pretty much use fuel stabilizer and hope for the best. Especially in my generator that may run once a year. I do turn off the fuel and run it dry. Not sure how good this is either. Seems to work fine.

Won't worry to much about octane at 91 ish.

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Skipper

Adding methanol IE race fuel, will up the octane value a great deal. Higher octane allows you (or the ECU) to advance the ignition further without ignition "knock", this is generating more power in engines that can utilize it.

 

The methanol burns colder, Much colder, and lowers the intake temp drastically, giving a denser fill. This is also true but not as pronounced with ethanol. That's the good side of running E gas. All engines likes cold intake, and everything that can reduce the running temp of an air cooled engine is a plus in my book.

 

There should be no mentionable concerns using high octane fuel, and certainly not anything in the "normal" range up to 95 or 98 which was common in ye olden days.

 

My guess is that CAT has just dropped the minimum requirements spec book, and let the office apprentice put it together again ;-)

Edited by Skipper
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lynnmor
2 hours ago, WHX16 said:

Interesting Lynn, what kind od motorcycle/engine, fuel injected?

It’s an old carbureted GS750 Suzuki.  It was running as good as ever but the very next time I started it with the Royal Farms 90 octane ethanol free, it missed, spit and sputtered and took some playing with the choke till it warmed and ran normally.   When (if) the weather gets back to normal, I’ll fill it with 89 from a busy station that might have the freshest gas, ethanol or not.

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dclarke

I run the non ethanol 91 octane gas in all my small engines, it is expensive and I have to drive 15 miles to get it but I think it's worth it. So far no problems.

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Shynon
36 minutes ago, dclarke said:

I run the non ethanol 91 octane gas in all my small engines

:text-yeahthat:

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JC 1965

:text-yeahthat: I run 91 octane ethanol free also.

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DennisThornton

The important thing to me is to not let ethanol/gas linger in your system!  Everything else is secondary!

 

Edited by DennisThornton
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Sarge

One thing to know about modern fuels - ethanol is not only corrosive to parts but is mainly used to boost the octane level of very crappy gasoline. Higher octane or not, non-ethanol fuels are a better quality base fuel which is always better at keeping deposits and damage at bay. Want proof? Try storing ethanol boosted fuels for long periods of time and enjoy the results of changing parts. I've used non-ethanol for a very long time after seeing mowers and other small engines come here with a lot of corrosion damage in the fuel system - not to mention valve damage.  The higher octane will normally have zero effect on a low compression engine - other than maybe the possibility of harder starting due to spark plug heat range and lack of cylinder pressure. I bring this up since there is a slight difference in how you should adjust your carb settings on fuel mixture, staying away from running rich if possible to avoid cylinder carbon buildup and spark plug fouling. 

 

The engine in the Cat-branded generator looks to be a Subaru/Robin or a clone - I see no reason 91 octane non-ethanol fuel would hurt it in any way possible.

 

Sarge

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