The Watercraft Journal IRL - Choosing The Right Fuel For Your PWC

[@gureno19]

All you need to remember about Octane rating is, higher the number the more resistant it is to pre detonation, hence why high compression, forced inducted engines need a gas that won't ignite before the piston hits TDC. High octane gas is technically LESS flammable then low octane gas, if you run low octane gas in a high comp engine, it will PING due to pre ignition before TDC.

[@watercraftjournal]

CORRECTION: Higher octane-rated fuel is a STRONGER molecular bond, not looser.

[@PRVRT1]

Good video, just wanted to point out that octane rating means how prone to pre-ignitiona / detonation a gasoline is. The higher the number is the less prone pre-ignition. Also, the spark plug does not fire at top dead center unless you are at 0 degrees ignition advance. In reality the spark plug fire before TDC and the whole flame front dynamics comes afterward.

[@watercraftjournal]

You're exactly right, Walter. Octane also stabilizes the molecular bond - higher octane fuel is less volatile (that's why US air servicemen could weld INSIDE of an airplane's fuel tank ankle deep in fuel). And yes, it's NEVER at 0º but trying to detail the complexity of ignition timing to an audience of PWC enthusiasts can be a little...challenging.

[@Yomama29111]

Kevin really knows his stuff. So helpful.

[@watercraftjournal]

Thank you! Please share to help us grow the channel!

[@NCDroneFlyer]

Hey Kevin, I learned a LOT from this video. Well done and many thanks!

[@watercraftjournal]

You bet!

[@robertogonzalez2551]

Hi I’m Kevin Shaw and I am a human encyclopedia. Good stuff man there’s a lot of science behind it. Thanks for taking your time to explain everything.

[@watercraftjournal]

LOL! We don't know about that, but thank you!

[@johnschumacher3618]

Great video u did a super job of explaining . Filled in the blanks for understanding. Thanks Kevin.

[@watercraftjournal]

Glad you enjoyed it!

[@khalilkenouche2063]

Kevin you are the Best. I have learned many things from you even whit my bad english .I stopped reading from social media.. because of stupidity there. Thanks 🙏🙏

[@watercraftjournal]

The Internet is a hive of scum and villiany.

[@jetskiordie3448]

My i also bad but good that Kevin spoke not so fast And have clearly dialekt heh

[@alfonsobruno2289]

I always ran on 87 gas IS it better to use addatife OR put better gasoline so i can clean out my engine once i while LOVE your show I REALLY enjoy it THANK YOU SIR

[@alfonsobruno2289]

using 93 gas will it do more mileage than 87 IS it worth it going the charge ?

[@watercraftjournal]

Always run superior gas when you get the chance.

[@maxflight777]

A quick question Kevin please ? “Your Sea-Doo engine is designed to run most efficiently with fuel of a specific octane rating. For all engines except the 300hp Rotax 1630 ACE - 300, look for unleaded fuel with an AKI (RON+MON)/2 octane rating of 87 (or an RON octane rating of 91). Craft using the high-performance ACE - 300 engine require a higher octane level for best performance, fuel economy and engine life. Use Premium gasoline with an AKI (RON+MON)/2 octane rating of 91 (or an RON octane rating of 95).These octane requirements can also be found in the Sea-Doo Operator's Guide that comes with each craft.” Why is the 230 (basically the same as the 300 ) not included in the Sea Doo fuel notes above ?

[@watercraftjournal]

This was answered in a previous post.

[@michaelglen6704]

In Australia people are reporting a fuel like E85 provides a cooling effect.

[@watercraftjournal]

Slightly yes, thus allowing for greater thermodynamic response to boost/compression.

[@Captain_Steve_S]

So when do the big manufacturers make these Skis with closed loop fuel systems so we can achieve optimum fuel efficiency? It's already been introduced by the tuners in the sled industry. It's safer monitoring fuel burn than waiting for the knock sensor to pull timing when the damage may have already occurred.

[@watercraftjournal]

That's a bit of a logic jump. Of course a closed loop circuit on a sled/snowmobile is ideal, but not so with boats. Closed systems suffer from heat soak and typically operate at a higher average temperature compared to open circuits.

[@Captain_Steve_S]

Yes agreed, that is true for the lower states, but around my neck of the woods we benefit from cold waters and cooler air temps most of the year. It will be interesting to see if the EPA will eventually force the recreational vehicle companies into a cleaner system with O2 sensors and closed loop fuel systems. Do you happen to know what stock AFR target numbers are on the SVHO?

[@watercraftjournal]

14.6 is Stoichiometric, but 12.2 is considered the safest best power at WOT (Wide Open Throttle).

[@costasgeorgiou5015]

Hey Kevin have you done a test with any SVHO top speed run on 87 ethanol-free VS 93 octane with ethanol. FYI Kevin 61.0237 is 1 liter so like a Yamaha SVHO is Little over 109 cubic inches 🤭

[@watercraftjournal]

No, but that's a neat idea.

[@costasgeorgiou5015]

@@watercraftjournalthe reason why I say that I think the 87 e free will do better then the (up too) 10 % ethonal in the normal gases here in VA. Most of my German cars that take premium seam to do better with the e free gas so I run it in my SVHO but I haven't tested it if I scrub and of my top speed I would think more out the hole then top speed is scrubbed. If I get around to testing it I get back to you but I been very curious. Also the station I use one offers efree in 87 or I would get it in higher Oct.

[@marwanshareef688]

@watercraftjournal. I have the rxtx-300 with SCOM (all stock) can I use octane 87 in emergency cases? thanks for your time

[@watercraftjournal]

No

[@marwanshareef688]

@@watercraftjournal is it because of the SCOM?

[@besottedferrarista4466]

Hey Kev, Sorry about the war & peace below! I know this was filmed 8 months ago so not sure if you’ll get this, but as a guy who spent his whole career operating some of the largest mining equipment on the planet I’ve never really been interested in why they work, just how to make gear work faster via operating techniques. I have to say I’ve really enjoyed your explanations on why engines, fuel, oil, impeller & pumps work - you should be a teacher your very good & entertaining!! Re the octane ratings for the Sea Doo engines. In Australia 🇦🇺 we only have 86 with ethanol then 95 then (98 which is the only fuel I’ll run in our cars). The only fuel at all of the marinas around here is 95 I’m guessing that it’ll be ok as you were saying that you run 93 in the US? Also we have a 40’ cruiser which I’m planning on using as a base for a week or so when we go away. This will mean towing our GTX 230 behind it but only at about 8 knots for an hour or so at a time to an anchorage to play. Is there any thing I’ll need to do to the GTX to prepare it for this? I towed my Kawasaki 650 stand up behind someone else’s boat once and only just caught it in time before it sank with water going back up the Venturi suction at the pump into the engine bay 😬 Only just got it started and was able to ride it around until the jet pump sucked all the water out again! Cheers Steve from Oz

[@watercraftjournal]

First, run the 95 octane. Regarding towing your GTX at that speed and for that long, that's really not recommended. Like at all.

[@asmckellar]

Rookie here ... love your content. So I will be receiving a couple of new Yamaha VX Limited HOs in a few months. The manufacturer recommends 87/regular for this model, but would you recommend using 93/premium instead when possible?

[@watercraftjournal]

Better quality fuel will NEVER hurt.

[@LifeBeginsOnTheWater]

Great information Kevin, thanks again

[@watercraftjournal]

My pleasure!!

[@savvycontractor1910]

Learned a lot here!!! So...Thank You!.. for all of the great content and information!

[@watercraftjournal]

You are so welcome!

[@russmoody8598]

Thanks for explaining metrics

[@watercraftjournal]

We try!

[@macnie4292]

Thank you so much that was very helpful information

[@watercraftjournal]

Glad it was helpful!

[@BrockoM]

Why do the Seadoo manuals say to fill the tank prior to storage and treat with stabilizer if you are recommending a few gallons?

[@watercraftjournal]

A full tank is preferred as it will keep the sensitive fuel pump, terminals and pickup submerged in fuel, unable for ethanol fuel or heavy condensation to corrode these surfaces.

[@BrockoM]

@@watercraftjournal thanks

[@BrockoM]

@@watercraftjournal thanks

[@domjohnson2579]

You can totally use 87 octane on all newer ski's. All those engines have knock sensors and computers that will adjust the timing to compensate. Not only can "use 87 to get home" you can use it all the time for years and years with no problems. No you won't get full horsepower but slightly less but who cares. On all my modern corvettes and anyone I know that has corvettes all use 87 octane gas because it's cheaper even though the manufacturer says use 91 at least. Won't hurt the engine at all. If your modding your ski for ultra horsepower maybe use 91 but if it's stock then 87 is fine all models all the time. If you have extra money to waste then go ahead and buy 91`.

[@watercraftjournal]

Pretty much exactly what Kevin explained.

[@domjohnson2579]

@@watercraftjournal Not really I heard a lot of "87 can get you home OK". Not only can it get you home Ok it can be used all the time with no problems.

[@watercraftjournal]

Disagreed. The knock sensor is REACTING to detonation, not preventing it. The "heat" of your plugs, the compression of the cylinders and timing of the ignition all depend on the proper octane fuel, unless otherwise tuned. Yes, 87 will get you home and you'll be fine if you stay out of the boost, but do not operate regularly on it.

[@domjohnson2579]

@@watercraftjournal Of course it does. The knock sensor tells the computer to adjust timing just like every other modern engine in the world. This is pretty much engine basics 101.

[@hempelcx]

@@watercraftjournal A modern car ECU will learn that it's always having to adjust for lower octane, so it will apply that change even before the knock happens. That's why you shouldn't switch back and forth based on how your wallet feels that day, just pick an octane and stick with it. I can't say whether or not the computers in PWC also use learning / predictive models.

[@russmoody8598]

Thanks interesting discussion

[@watercraftjournal]

You bet!

[@SaltyDogPerformance]

The major concern with that low of an ethanol content in pump fuel is deterioration of the fuel system.

[@watercraftjournal]

Not so with modern plastics and rubber. Ethanol really only corroded old fuel systems and softer (low pressure) fuel lines on classic cars and old boats.

[@SaltyDogPerformance]

@@watercraftjournal would you say it’s fine to have a PWC sit for a few months during the winter with ethanol blended fuel in the system?

[@watercraftjournal]

If you properly treated it with a fuel stabilizer, yes.

[@evanleo7633]

Hi Kevin! In absolute emergency, can I use 87 in stage 1 tuned GP svho or rxpx300?

[@watercraftjournal]

No. The Stage 1 reflash will not allow the engine's knock sensor to retard the ignition advance enough to keep the engine from detonating (pre-ignition). Either bring enough fuel with you, plan your fuel stops accordingly, or don't build your ski so far out that you can't ride the dang thing.

[@evanleo7633]

@@watercraftjournal thanks for replying! I’m planning on carry the maptunerX in my car so I can return to stock tune in case I can’t find 93

[@watercraftjournal]

Yes, but if you’ve modified your supercharger and/or injectors, you’ll also have detonation issues.

[@evanleo7633]

@@watercraftjournal all I have is the tune other than that is fully stock

[@TheStephenspann27]

14:30 I thought the higher the octane the more “resistant” to combustion? That’s why you need it in higher compression engines. It resists Pre detonation. You state that it combusts “easier”

[@watercraftjournal]

It's a more complete burn. Less waste.

[@joshuarife5230]

I've heard the same thing that higher octane resists combustion(pre-detonation) and knock, the more compression the more heat. That's why boosted engines need higher octane because the extra air being shoved in the combustion chamber increasing pressures. As you've stated about knock sensors allow alot of modern engines to run lower octane fuels by detecting knock and therefore the ecu injects extra fuel to prevent that pre-ignition. That's why if you run lower octane fuels in engines that prefer higher octanes get worse mpg.

[@hempelcx]

@@watercraftjournal It's not quite true that higher octane fuel produces a more complete burn. Octane is *only* a rating of how much compression it takes to induce combustion, nothing else. It is true that a lot of gasoline manufacturers use higher grade fuel in their higher octane (aka "premium") offerings, so you can end up getting a cleaner / more complete burn because of that. But octane doesn't inherently cause that. In other words, putting 92 octane fuel in an engine designed for 87 octane fuel will not result in a more complete burn, in both cases, an ideal burn is possible (all else being equal.) However, you are correct that an engine designed for 92 octane fuel will get knock running 87 octane fuel, and in that case, modern engines will inject more fuel and wind up with unburnt fuel, less power, and worse efficiency.

[@JDDD33]

Dude. This video was fantastic. Keep up the amazing work !! Cheers, from Kangaroo land 👍

[@watercraftjournal]

Appreciated!

[@dproulx7380]

Kevin can you pls post hyperlink for that worx /riva sponsons comparisons thank you

[@watercraftjournal]

Knock, and it shall be opened unto you: watercraftjournal.com/gallery-understanding-fluid-dynamics-in-relation-to-superior-sponson-design/

[@dproulx7380]

Thanks Kevin really appreciate!!!👍🏻👍🏻👍🏻👍🏻

[@dproulx7380]

I’m sad I cheaped out and purchased the worx sponson I would have definitely spent the extra 120 if I seen your article !!! That said Kevin I have 19 gp I have stage one tune free flow exhaust not a lot of upgrades but I’m thinking of grabbing riva gen 2 intake grate and pump seal what’s your option on that ??? I figure improve handling at this point and hook up !! Thanks for listening 👂

[@watercraftjournal]

The intake grate and pump seal kit will dramatically improve initial acceleration and hook up throughout the powerband. (Not so much handling/cornering.) The grate and seal kit provide traction and reduce cavitation, meaning launching from a standstill or pulling out of the apex of a turn will feel radically different/stronger. -K

[@nicholasfleet9805]

Hi Kevin, I know you didn’t really want to touch on Octane but I have a question. In the UK the standard octane is 95 in unleaded petrol (we also have 98, super unleaded). According to the Seadoo Spec sheets. The GTI 130 & 170 are both 95 octane rated engines. The Wake 170 however is 87 octane. Why would this be? I thought it was the exact same engine is it not? This leads up to, if I’ve got this right, by and large its OK to run 87 octane in a 95 rated engine but NOT OK to put 95 octane in an 87 octane rated engine, is that correct? On that basis I would not risk buying a Wake 170 in the UK as it is an 87 octane rated engine and UK fuel (at 95) would knacker the engine. Is this right? (PS I don't yet own a PWC but am in the market). Thanks for any input :)

[@watercraftjournal]

It might be the difference in octane measurements between the US and UK. Yes, the 1630 ACE 170 is identical worldwide, so it might be a case of US measurement vs. UK. Double check to verify that they're using the correct scale because us Yanks like to muck things up with our Standard Units of Measurement. (#screwmetric)

[@TheVonMatrices]

@@watercraftjournal This has nothing to do with imperial vs metric units. Most of the world uses the Research Octane Number (RON) test to rate gasoline and displays that at the pump. The US and a few other countries use the AKI (Anti-Knock Index), which is the average of two tests - the RON test and the Motor Octane Number (MON) test. The MON test is a more difficult test that is run at high RPM and results in lower scores. It doesn't mean the gasoline is any different; it's just that the AKI rating includes a more difficult test. So you could actually say that US gasoline is better because it has to pass more stringent testing before being sold.

[@watercraftjournal]

You CLEARLY missed the joke.

[@aaron-fauth]

@@TheVonMatrices the joke flew over your head

[@anthonyregan9957]

Great video Kevin.. keep it up dude I could watch your videos 24/7 365 keep em coming 🏁🏴󠁧󠁢󠁥󠁮󠁧󠁿

[@watercraftjournal]

Thanks! More to come!

[@ericflores5748]

What about if I use 87 and add lucas fuel additive

[@watercraftjournal]

Don't ask for permission to disagree with me. Do or don't.

[@gustavohenrique281M]

Is there any advantage in using a 95 to run a FXHO?

[@watercraftjournal]

Not enough for you to notice.

[@maxflight777]

Just as a “ jokey “ observation 😂 At 8000 rpm , there are not 8000 explosions every minute ! Half that !

[@watercraftjournal]

You're 100% correct. I misspoke. -K

[@reissallan]

i love your channel, but these videos are waaaaay too long.

[@watercraftjournal]

The IRL videos are long form/discussions. We produce two 10-minute videos each month.

[@carlosbauzo4890]

440 is actually 7.2. 7.4 is a 454

[@watercraftjournal]

Yes, you're 100% correct. I misspoke.

[@catfish307]

Ruined 2 high pressure fuel pumps in a newer Evinrude Etec by using Ethanol fuel and all the additives bells and whistles. If I had to run ethanol in any water craft for any reason I'd drain the tanks and run it dry at the end of the day. Ethanol = a big ass sponge for sucking water into your fuel system. Nothing but non ethanol goes into any of my watercraft, period..

[@watercraftjournal]

Yikes. Sorry to hear that. But we're pretty sure there was something else wrong there. Possibly contaminated fuel as modern engines and fuel pumps are designed (and built with treated materials) to operate using 10% ethanol fuel.

[@bg-kx9et]

The E-tec motor is 2-stroke. No 2-stroke motor should have ethanol fuel, pure 91 or higher. Additives including fuel stabilizer make the e-tec run poorly. This is very evident on their E-tec snowmobile motors, most notably the 600.

[@takemopenn]

educate these rooks lol

[@watercraftjournal]

Many just don't know this stuff.