Octane Boost - 2 Stroke Engines

[plowtruck]

I was just curious if any of you guys add octane booster to your pump gas on 2 cycle engines and how you like it? Does it do any damage to the internal engine parts? Im thinking about upping the octane on my dirtbike and am steering in the direction of adding octane booster or mixing aviation gas with pump gas. Which is the better route for the better part on engine life? Thanks

[Nytemare]

I was just curious if any of you guys add octane booster to your pump gas on 2 cycle engines and how you like it? Does it do any damage to the internal engine parts? Im thinking about upping the octane on my dirtbike and am steering in the direction of adding octane booster or mixing aviation gas with pump gas. Which is the better route for the better part on engine life? Thanks

Don't know if you already know this or not, but Octane is the INABILITY of gas to burn. You will bun 87 octane far easier than 92. Having said that...your compression ratio is a big factor in the octane you can run...for example...any engine up to about 9.5:1 can burn 87 octane fine...from there up to 10.5:1 you will need mid grade, and 10.5 to about 13:1 you have to use premium fuel of a minimum of 92 octane...

 

Avgas is roughly 110 octane, and is good for about a comp ratio of higher than 13. But unless you have the compression ratio to burn the fuel, or your timing properly adjusted with a Multi spark ignition, you will have much more unburnt fuel causing carbon deposits etc. The other issue is that higher octane fuels burn much hotter than regular fuel, and can play havoc on engine internals, spark plugs, gaskets and seals.

[REV353]

What has been done to the motor?, what are you modifications and compression ratio?.

[90454SS]

Octane booster won't hurt your motor at all. If the motor is detonating under a load, it will help. If not, it's a waste.

My yz250 will detonate a little in hot weather under a load....I can't jet out the pinging and have it run cleanly. So I use cam2 or VP race gas to stop it. I use to use avgas but it had a bit of antifreeze(not automotive) in it to keep it from freezing at altitude. It made my bike run inconsistently and I had to rejet. I use to race cross-country alot, enduros, and it would be cold in the morning and warm later; the bike ran differently as the day wore on.

If you are very concerned about engine life on a 2stroke, rejet a little fat and use good premix oil...PJ1 goldfire pro used to have octane booster in it. If you're hard on the bike you'll go thru topend's a little more quickly...I changed topends twice a year but now can get a while out of them.

I was just curious if any of you guys add octane booster to your pump gas on 2 cycle engines and how you like it? Does it do any damage to the internal engine parts? Im thinking about upping the octane on my dirtbike and am steering in the direction of adding octane booster or mixing aviation gas with pump gas. Which is the better route for the better part on engine life? Thanks

[Silverado4x4]

Octane boosters do not work, the bottle might say "raises octane 8 points" that does not mean if you put 87 in your tank and then a bottle of octane boost it will go to 95 it means 87 octane will go to 87.8. I use to run cam2 and Bell-Ray oil in my YZ-125 years ago (like 30) but it runs hot and went through top ends pretty fast.

[Prokopchuk_9]

its not gonna hurt anything man, the difference is so small you wont notice anything...just dont hold it wide open and you wont blow it up. just like any other 2 banger. ive never used anything but 50/50 supreme/VP in my bikes...my last sled i had last year now sold...was an 03 firecat 700. 144" EXT kit, clutched, geared a little lower. 2.25" finger track on it, boondocker control box and nitrous kit. BMP head, black magic y-pipe, black magic pipes with dual stingers. set up for 800 footers... i had a EGT gauge on it cuz i also had the timing advanced 2 degrees, i had to run race fuel. but before i put that in the sled had a little switch to retard the timing for you depending on which fuel you used. i tried reg fuel a couple times (broke LOL) and when i ran supreme the EGT's never changed really at all...food for thought...by the way. that sled was F**KING FAST

[Toadz]

I was just curious if any of you guys add octane booster to your pump gas on 2 cycle engines and how you like it? Does it do any damage to the internal engine parts? Im thinking about upping the octane on my dirtbike and am steering in the direction of adding octane booster or mixing aviation gas with pump gas. Which is the better route for the better part on engine life? Thanks

 

Do not run octane boosters. Huge waste of money. Run only premium fuel and make sure you're jetted correctly. That is the best route for prolonged engine life. Also make sure to use a high quality two-stroke oil like Amsoil.

[00_Extended]

Octane booster won't hurt your motor at all. If the motor is detonating under a load, it will help. If not, it's a waste.

My yz250 will detonate a little in hot weather under a load....I can't jet out the pinging and have it run cleanly. So I use cam2 or VP race gas to stop it. I use to use avgas but it had a bit of antifreeze(not automotive) in it to keep it from freezing at altitude. It made my bike run inconsistently and I had to rejet. I use to race cross-country alot, enduros, and it would be cold in the morning and warm later; the bike ran differently as the day wore on.

If you are very concerned about engine life on a 2stroke, rejet a little fat and use good premix oil...PJ1 goldfire pro used to have octane booster in it. If you're hard on the bike you'll go thru topend's a little more quickly...I changed topends twice a year but now can get a while out of them.

I was just curious if any of you guys add octane booster to your pump gas on 2 cycle engines and how you like it? Does it do any damage to the internal engine parts? Im thinking about upping the octane on my dirtbike and am steering in the direction of adding octane booster or mixing aviation gas with pump gas. Which is the better route for the better part on engine life? Thanks

 

 

Read this post very carefuly. It's telling you to jet correctly, run a good pre-mix and I will add that after that you stick with the same one. Do not use Av gas for reasons stated above. You best bet is a quality fuel, quality pe-mix correct jetting and maintaining your ride. If you not racing for factory team jetting little fat is going to save your top end big time. Also never shut off the gas and let a 2 stroke run out of fuel in the carb, you just drained the oil that lubricates it!! After a long or hard ride I always let mine idle little or even on the way back to camp I pull the choke a little to load it up some and ride just little bit just cruising to even up the temps. I ran NGK gold plugs and have had top ends last seasons in my banshee. I don't own it anymore but I look at this way. A little more for a consistant plug, better fuel and pre-mix and not trashing your equipment will save you loads of cash down the road. Do it the right way and if you don't know how to jet it or figure out which way to move your carbe needle or other settings take some place that does. It will be money well spent.

[plowtruck]

I don't have access to race fuel. All we have here is 87 octane, Im in an isolated town with one gas station. Ive got a 2006 YZ250 with a eric gorr 295cc big bore kit, port and polished cylinder, milled head, stock pipe, bills pipes silencer, vforce 3 valve, twin air filter, etc, all the bolt on parts. The bike flat out rips!! I ran 50/50 av gas and 87 pump gas in it last season and it was real finicky, it seemed like I was always rejetting and changing plugs. I wasnt familiar with octane boost so I thought Id ask. I use Amsoil Dominator premix but am thinking of switching to Klotz, I have heard bad things about Amsoil. But everyone has their opinionI need to do something about the gas Im burning. I have 175lbs of compression over 130lbs stock. The bike runs good but pings every so often whenever under serious load and most of the time pings during hill climbing. I have about 20 hours of riding time (have an hour meter)since I put the big bore kit on. Im going to be tearing down the engine within the next month to inspect everything. I have a friend with a $3k SLP motor in his 800RMK that runs straight av gas and has had alot of problems so Im steering away from it. Im thinkin the best thing to do would be to rake out the cash and buy a 50 gallon drum of premium at a time.

[gregrocks89]

you dont have a bike or quad dealership near ya to get some c12?

[plowtruck]

i live in a town where you have to fly an airplane too or take a ferry.

[Black02Silverado]

I second the use of premium fuel over octane boost. You really do not need to run a high octane unless your equipment calls for it or you raised the compression ratio and need the increase octane to keep detonation down.

 

Run quality fuel, oil and proper maintenance and your should be good to go.

[90454SS]

Eric gorr has head mods that can reshape the squish band and help reduce or eliminate detonation. That milled head probably didn't help either. With the mods you have premium may still detonate..it does in my yz250.

Also some of the race gas' can be shipped although somewhat expensive, it's cheaper than grenading the topend. You can mix the race gas with your gas so it lasts longer.

[gregrocks89]

ahh i see. i use to work at honda we would always run c12 on modded 2 strokes usually, other then that we used shell premium for everything.

[00_Extended]

Shell premuim id a good fuel to use. I would recomend Yamalube R for a pre-mix. I used it for years without issue.