Fuel estimate

[kimchee]

Okay soo I picked up a 5 gallon jug of C12 for the RS125. Ill be doing BARF and ZOOM ZOOM back to back next weekend. Assuming I run B group pace (hopefully) how much Gas you think Ill need???

Think I should get another 5 gallon JIC (just in case)

?

would suck to not be able to ride just cuz I run outta gas

[Mortifer]

Don't they have gas at the track?

[kimchee]

Okay re-reading my post...the obvious answer would be just bring a second jug u idiot


I guess what Im askin is how much gas do you think a track day will consume assuming I run a B group pace and all sessions

[kimchee]

Okay rereading my second post...I know there are lots of vaiables like jetting and how I ride....

I just need some guestimates

[rick]

Er, they have gas pumps at the track. Sure, it's more expensive than your local gas station but, it is another option.

[kimchee]

Im running C12 its a leaded 108 octane race fuel.
Okay better qestion....CAN I EVEN USE PUMP GAS?!?!?

[JnglstTICAL]

The gas at the track is race fuel.....I think...

[Roscoe]

Sounds like you answered your own questions.

Btw, BRING A FOOK'N FUNNEL!!!!!!! (oh yeah, the R1 too :teeth )

[nine]

duh...
why don't you ask the guy you bought the bike from?

There's only a few people on here that have experience with a riding two stroke on the track (equals-D, twostroker, ???)

and yeah, you answered your own question...sheeeesh!

[luisimo]

As I am new to the two stroke wolrd (as you are) I know the frustation that this threath can give you :teeth
I will be running my 125 with 100 octane unleaded as that is what the prior owner used to put on the bike. Check with your prior owner some people like leaded 100+ others like unleaded 110+

I heard that unleaded 110 works really good with the rs125 but make sure that you have the right jetting.

[luisimo]

Oh yeah the answer....

You should get an average of 20-30 miles per gallon out of the rs125 so do the math. You should be OK with five gallons though.

[equals D]

You'll need more than 5 gallons. You'll go through about 4-5 gallons a day at that pace. Bring pre-mix too. You'll need a liter of pre-mix for every 7.4 gallons, so bring 2 liters of pre-mix. DO NOT change pre-mix. DO NOT use pump gas. DO use quality fuel. You do not want to have your engine seize as you sail through turn 8 at redline in 6th gear. (And when you get up to speed, that's what you're doing when you go through T8). It's a very negative experience. Actually it's a pretty negative experience when you seize your motor anywhere. That bike isn't a toy. It's the real deal. Treat it with respect and you'll have more fun than you thought was possible. Treat it like a 2-bit ho and it'll bite you in the ass chewing through your wallet to get there.

Your jetting is not going to affect your fuel comsumption noticeably.

[kimchee]

Originally posted by equals D
You'll need more than 5 gallons. You'll go through about 4-5 gallons a day at that pace. Bring pre-mix too. You'll need a liter of pre-mix for every 7.4 gallons, so bring 2 liters of pre-mix. DO NOT change pre-mix. DO NOT use pump gas. DO use quality fuel. You do not want to have your engine seize as you sail through turn 8 at redline in 6th gear. (And when you get up to speed, that's what you're doing when you go through T8). It's a very negative experience. Actually it's a pretty negative experience when you seize your motor anywhere. That bike isn't a toy. It's the real deal. Treat it with respect and you'll have more fun than you thought was possible. Treat it like a 2-bit ho and it'll bite you in the ass chewing through your wallet to get there.

Your jetting is not going to affect your fuel comsumption noticeably.


:thumbup :thumbup


Thanks man
Ill make sure to bring 10 gallons
WOOT WOOT

David


PS I got plenty of respect for that racin machine...NOT TOY

[equals D]

Originally posted by lu1s1m0
As I am new to the two stroke wolrd (as you are) I know the frustation that this threath can give you :teeth
I will be running my 125 with 100 octane unleaded as that is what the prior owner used to put on the bike. Check with your prior owner some people like leaded 100+ others like unleaded 110+

I heard that unleaded 110 works really good with the rs125 but make sure that you have the right jetting.

Ok, you bought the pre-95 RS125, right? That bike was made to run on leaded fuel. Check with the previous owner if the head and carb were modified for unleaded fuel. If not, then you're going to see what detonation will do to your head and piston. It's kinda cool, but it ruins them. Leaded fuels will help your cranks last longer, too. It makes more power with leaded fuel and it runs cooler too. It wasn't until '98 that Honda started making RS125s to run with unleaded fuel.

[equals D]

Hey Kimchee,
For T'hill you should use 15/37 gearing. Actually, 15/37 will be good for Sears Point and B'willow too.

Also, some common mistakes that people make when they first start riding these bikes:

No, it won't idle. It's not set up to idle. Don't adjust it so it will idle. You know how the 2-stroke guys keep blipping the throttle all the time. They do that because it won't idle. Plus, each time you blip the throttle you flood the cylinder with gas and the only oil the piston is going to see comes in with the gas. If you hold constant throttle for a long time it's going to seize.

No, there's nothing wrong with the engine. It's going to take about 70 yards of sliding the clutch with the engine spinning above 10,000 rpm to get the bike moving. It's a race bike and has a close ratio transmission. First gear's good for about 60 mph and it tops out at about 120 (with the 15/37 gearing). It makes no torque, so you have to spin the motor so that it makes enough hp to get the thing going. If the rpm drops below 10,000 rpm it'll make a bad "BAAAAHHHHH" noise and not accelerate at all. Keep it above 10 grand and it'll sing and that will make you smile.

Yes, those are good brakes. Be easy with them at first. Lifting the rear while braking is a no-brainer with those.

Make sure you have removed the carb cap and exhaust plug before you try starting the bike. Also make sure that the fuel is on, the cut-off switch is on, and the spark plug cap is on.

Set your tire pressure to 25 front, 26 rear.

The chain will look loose when it is adjusted properly. It should have 1 inch of slack when measured at the top run of the chain.

=D

[luisimo]

To equals_D

Hmmmm, I am not sure if the prior owner knew that. the bike currently has a brand new top end, and it was just broke in with unleaded 100, I should rethink what gas I am going to be using. I doubth that the head and carb were modified for unleaded fuel.

The crank has gone through two rebuilds, perhaps I should consider running leaded then. Man, I need to know when you are going to a BARF meeting so I can bombard you with a ton of questions.

[equals D]

Better yet, you should come to my garage when I'm working on my bike.

[luisimo]

Originally posted by equals D
Better yet, you should come to my garage when I'm working on my bike.


You are on :thumbup

Just let me know when.

[kimchee]

Can I come too???
woot woot

thanks for the info Equals D. Ive been tinkering with the bike a bit and have already stalled it a few times. All is good. I just cant wait to get it out to the track. Even in slow turns the thing feels like its stuck to the ground.

One more question...how often do you change reeds?

[equals D]

Originally posted by kimchee
Can I come too???

One more question...how often do you change reeds?

Yes, you should come too. Reeds can be changed on an as needed basis. If you want to be anal about it, change them with every top end. The plug cap should be changed about that often too.

[GetaGripGreg]

I can second equalsD on at least one thing:

DO NOT RUN PUMP GAS

When I took my CR125 shifter out the first time, I thought I could get away with 93 octane because I was going to be taking it easy. Stick. Scratch one cylinder.

Fuel and oil are the most important things to your two stroke. I've not run a RS125, but many of the top national kart guys that run CRs with RS top end components run VP C12. In fact, it's the spec gas for the SKUSA ProMoto Tour. Good stuff.

I was stuck running 100 octane ELF fuel once 900 miles from home, with my brand new tuned motor. I stuck it in the third practice session.

I'm so damn jealous!

Have fun.

[luisimo]

OK, so I am reading the rs125 manual and it tells me to only use leaded gasoline, the bike has a compression of 8:1 and after some reading, I find out that vp racing fuel PERFORMANCE LEADED it is good up to 11:1 compression

Why is it a need to run C12 if the engine only has a compression of 8:1 when the C12 supports up to 15:1? Also Unocal 76 leaded supports up to 13:1, which one is better VP performance leaded or Unocal76 racing leaded?