Thoughts on Octane boosters, fuel additives, and ethanol free?

[Srawl]

Im about to put in the first tank of fresh gas that this thing has seen in a while and I have no idea what the previous owners ran through it.

When I drained the tank after purchasing, the gas was BRIGHT yellow (think highlighter) not sure what that was all about but I decided I can’t go wrong just starting fresh.

Local stations only go up to 93 octane but I also have an option to use 87 octane ethanol free. The 87 ethanol free is $1.23 more per gallon than the 93.

My current idea is to get the ethanol free, treat with some octane booster, sea foam, and sta-bil. Someone also suggested a lead additive...

From what I understand these bikes run best with about 95 pure gas octane correct?

 

[mrtwowheel]

Bottom line for me...…….I won't own a vehicle that will not run on regular gasoline. Sea Foam is good stuff, I use it in a drastic dose when starting my bikes for the season. People who say that they don't see a difference when using Sea Foam are following the directions. You need a drastic dose to see a difference. 1/3 to half a can to a full tank of gas will do wonders for carbs and carbon build up on valves, rings and pistons. Another additive that I use is two stroke oil (TC-W3), this is not the old two stroke oil that fouled plugs, it will do the same cleaning as Sea Foam and stabilize the fuel. I use about 2-3 ounces to a full tank about 2-3 times per season. I've noticed just a slight raise in RPMs at idle when using TC-W3. I use the TC-W3 to treat the fuel and carbs for storage, I do not drain the carbs for storage, just run the bike long enough to be sure that there is a fuel/TC-W3 mixture in the carbs. In the spring I remove the stored fuel and put it in the lawn mower and start with fresh fuel and Sea Foam. No seasonal carb cleaning necessary.

Scott

 

[jetmechmarty]

Use the E0 and you won't have carburetor problems. 87 E0 should work just fine.

I once got my mower to run on a 50/50 gasoline/Sea Foam mixture. It does a fair job of clean up, but is not a substitute for breaking them down for cleaning. All my yard equipment now gets a steady diet of E0. I no longer suffer those issues. Ethanol+carburetor=TROUBLE

 

[delagem]

I wouldn't use most of those snake oils, Stabil excepted (and even then only for storage in the off-season which I suspect you don't have, being in TX).

Read up on octane; it's not a performance enhancer of any kind, it actually lowers the BTU's of the fuel. Look up your compression ratio (oh no, don't start that again!), and see what octane fuel you should be using.

Sea Foam? Why? If you've got an issue, sure, or Techron, or whatever. It certainly isn't going to "fix" anything.

Lead additives? I've never given them any thought.

Clean fresh gas, clean carbs, an inline filter. Don't overthink this.

OctanevsCompressionSmall by michael delage, on Flickr

 

[Srawl]

I wouldn't use most of those snake oils, Stabil excepted (and even then only for storage in the off-season which I suspect you don't have, being in TX).

Read up on octane; it's not a performance enhancer of any kind, it actually lowers the BTU's of the fuel. Look up your compression ratio (oh no, don't start that again!), and see what octane fuel you should be using.

Sea Foam? Why? If you've got an issue, sure, or Techron, or whatever. It certainly isn't going to "fix" anything.

Lead additives? I've never given them any thought.

Clean fresh gas, clean carbs, an inline filter. Don't overthink this.

OctanevsCompressionSmall by michael delage, on Flickr

In Texas this summer is the off-season, it’s almost too hot to ride. The reason for seafoam is to clean up the valves and what not preventing issues in the future.

 

[jetmechmarty]

I don't believe Sea Foam will prevent ethanol poisoning.

 

[grizld1]

Higher octane rating=slower flame travel, a requirement for preventing detonation in older high compression motors without the benefit of modern head design and ignition control (modern twins like the Suzuki SV650 and Kawasaki EX650 run safely on 87 octane regular gas, although the static CR in those motors exceeds 11:1--that's not engineering, it's sorcery!) Back in the days when AMA rules required spool hubs front and rear on flat track bikes and allowed 45 ci. (750 cc.) sidevalvers to run against 30.5 ci. (500 cc.) OHV machines in the Expert class, Hardly Ableson used low octane regular as their racing fuel. Reason: slow flame travel is the last thing you want for performance in a flathead combustion chamber.

Get four experienced XS650 guys together and you'll get four opinions on fuel, some of them right strong (we had to ban that topic of conversation at rallies because of all the fist fights breaking out). Here's the bottom line: A stock XS650 will run fine on fresh 87 octane regular, but 92 or 93 octane premium is usually more stable and provides a cushion of safety against detonation.

There is no need for lead additives in the XS650 motor. Tetraethyl lead was added to fuels back in the day when valve seats were made of softer material; the additive protected the valve seats. Like all Japanese motors of its period, the XS650 has valve seats that are made for use with unleaded fuel. Lead additives won't buy you a thing.

 

[grizld1]

Srawl, check ebay, etc. and get a copy of the owner's manual for your bike. You'll find that Mama Yama's recommended fuel is 87 octane regular. Don't know who's been spinning yarns about 95 octane. I haven't seen that high an octane rating offered at the pump since Sunoco quit selling it, and at a static CR at or below 8.6:1, a stock XS650 motor is a long way from needing it.

 

[xjwmx]

I would get pinging with 87 and 93, no difference, till I set my timing back some, now I use 87

I do pay attention to brand. I'm convinced some of them are a convenient way to dispose of waste chemicals.

 

[CoconutPete]

I got lucky when I stopped at a random gas station near my house. Look at that! Ehtanol free gas at the pump in the middle!

That's about all I do. She runs great and doesn't complain when she doesn't get ridden for a few weeks.

 

[delagem]

I'm convinced some of them are a convenient way to dispose of waste chemicals.

I work in this industry. I can't confirm any disposal of waste chemicals, but I can confirm that when a tank is being taken from one grade to the next, all the leftovers are indeed stripped to the Regular tanks. So trace amounts of diesel, jet fuel and anything else are frequently in there.

Some people worry about ethanol in their gas. Especially with personal watercraft. I have never sought out ethanol-free gas, and store my PWC and motorcycles 7-8 months at a time, with no ill effects; I've been doing this for decades on some. It's a non-issue.

If buying ethanol-free makes you feel better, great. You're helping to support a farmer somewhere! But it really isn't needed.

 

[gggGary]

I'm corny and run it. the stockers all get regular. Madness is special, and slurps from the $$ pump.
A few situations where corn gas can bite; sitting long term in high humidity it will absorb water, separate, and sink, motors don't like to run on a water ethanol mix.
Using ethanol in a barn bike that has never used it. The alcohol is a good solvent it dissolves any varnish in the tank then heads for the low point, can gum up carbs pretty bad til the varnish gets cleared out. That's it otherwise never an issue with it.
Some crap rubber won't take it but I've never had a problem with any in the XS's
Fiberglass gas tanks, again ethanol is good solvent it can dissolve old resin not designed to withstand it. I have a "new" fiberglass tank that was destroyed,.

 

[FLEA]

mmm... what about titanium valves , have them in 1 of my xs650s ,should I run a lead adative and what fuel

 

[highboy_coupe]

It's the valve seats you have to watch on older vehicles, think British 60s/70s stuff.
Your XS valve seats, and your titanium valves, will be fine. I have heard the usual stories from both sides about titanium valves, from "lead will strip the special coating", to "lead makes the valves last longer".
There are high performance cars that use titanium valve seat inserts and sodium alloy filled titanium valves, they dont require lead additives to work.

 

[grizld1]

+1, highboy! Guys, before you listen to anybody pushing lead additives, replacement valve seats, etc., find out if they've actually built a few engines and if so what kind. There's a lot of ignorance peddled by those who don't know the difference between the soft valve seats in a 1960's Harley, Triumph, BSA, Norton, Ariel, Velocette, etc. and the hard seats in Japanese motors from the 1970's and in some cases the late 1960's. There's way too much misinformatiion "shared" by guys who've gotten their ideas at third, fourth, or fifth hand. Remember the old party game of "telegraph?" Things get garbled as they get passed. Oral tradition is a fine thing for folklorists and story tellers, but only a fool trusts it when it comes to motors. Peace.

 

[FLEA]

It's the valve seats you have to watch on older vehicles, think British 60s/70s stuff.
Your XS valve seats, and your titanium valves, will be fine. I have heard the usual stories from both sides about titanium valves, from "lead will strip the special coating", to "lead makes the valves last longer".
There are high performance cars that use titanium valve seat inserts and sodium alloy filled titanium valves, they dont require lead additives to work.

thanks... it was something hadn't thought of until reading these posts as always heard/read the xs didn't need the addative BUT wasn't sure with the titanium valves

 

[Srawl]

+1, highboy! Guys, before you listen to anybody pushing lead additives, replacement valve seats, etc., find out if they've actually built a few engines and if so what kind. There's a lot of ignorance peddled by those who don't know the difference between the soft valve seats in a 1960's Harley, Triumph, BSA, Norton, Ariel, Velocette, etc. and the hard seats in Japanese motors from the 1970's and in some cases the late 1960's. There's way too much misinformatiion "shared" by guys who've gotten their ideas at third, fourth, or fifth hand. Remember the old party game of "telegraph?" Things get garbled as they get passed. Oral tradition is a fine thing for folklorists and story tellers, but only a fool trusts it when it comes to motors. Peace.

That’s why I ask on here. Between the three manuals and this forum, I feel pretty safe.