Jump to content
Sign in to follow this  

Lead and octane

Recommended Posts

I have had some pinging issues lately and found out that i can purchase 110 octane leaded gas at a local station. i have been running 91 (ethanol free) gas.

the bike: 2005 RM265 with head porting.

first can my bike handle leaded fuel?

second can my bike handle 110 octane or should i mix it half and half with 91 giving me something like 100.5 octane gas? or maybe 3:1 for 95.75 octane?

Share this post


Link to post
Share on other sites

yes, your bike can handle leaded fuel. in fact, lead is a good thing since it is a lubricant for your valves. The only time lead becomes a problem is with catalytic converters.

as far as the octane goes, wour bike can handle any octane above the recommended. However, the question is: do you really need it? are you sure the pinging is not caused by something else?

Share this post


Link to post
Share on other sites

was the compression raised in the bike, if not then you should not need race fuel. i mix 50/50 110 with 91 works great.

Share this post


Link to post
Share on other sites
yes, your bike can handle leaded fuel. in fact, lead is a good thing since it is a lubricant for your valves. The only time lead becomes a problem is with catalytic converters.

This is a 2 Stroke so no valves, but should still be ok?? or is it only a benefit to 4 strokes?

as far as the octane goes, wour bike can handle any octane above the recommended. However, the question is: do you really need it? are you sure the pinging is not caused by something else?

well, i can't be sure that the ping is from the octane of the gas, but i put some octane booster in my current gas and the ping went away and the bike seemed to run flawlessly, so i'm guessing that is the problem.

Share this post


Link to post
Share on other sites
was the compression raised in the bike, if not then you should not need race fuel.

well, when i spoke to Eric Gorr, who did the work, he said that the head was ported for "more power throughout the powerband" which i'm guessing means higher compression. He also said it should run on pump gas, but he kind of hinted to the fact that higher octane would run better.

i mix 50/50 110 with 91 works great.

and that is what i was planning on doing. my current gas is ethenol free 91 octane and i was planning on mixing 1:1 with 110 leaded gas that i found at a local place. should net about 100.5 octane which i was hoping would be ideal for the bike. I'm just trying to make sure that i know what octane i should be shooting for and if lead is ok in a 2 stroke.

Share this post


Link to post
Share on other sites
This is a 2 Stroke so no valves, but should still be ok?? or is it only a benefit to 4 strokes?

well, i can't be sure that the ping is from the octane of the gas, but i put some octane booster in my current gas and the ping went away and the bike seemed to run flawlessly, so i'm guessing that is the problem.

if some octane booster stopped the ping than tou don't need much higher of a octane rating.i'd say you whould only need a mixture of 90%91 and 10% 110 to keep the ping away. when it comes to octane you only need enuf to keep it from pinging above that level your only reducing power output of your engine and putting a bigger dent in your wallet than you have to. as for 2 strokes and leaded fuel , they love it ! I burn 55 gallons through my 780cc 185 hp 2 stroke snowmobile every winter .my head set up requires 96 octane and i mix for 97 and the thing loves it .

Share this post


Link to post
Share on other sites
This is a 2 Stroke so no valves, but should still be ok?? or is it only a benefit to 4 strokes?

well, i can't be sure that the ping is from the octane of the gas, but i put some octane booster in my current gas and the ping went away and the bike seemed to run flawlessly, so i'm guessing that is the problem.

Lead is fine for your 2 stroke, I often do an Avgas/ pump mix in my 2 and 4 strokes.

If booster is curing your ping you won't need much. 3-4 parts pump to 1 part 110. Experiment, see what works for you.

Share this post


Link to post
Share on other sites

Perfect!!! Thanks for all for the responses, they were all very appreciated!

Share this post


Link to post
Share on other sites
I wrote valves, I meant engine in general. lead is a lubricant.

Personally, I use the below in my 4-stroke:

http://kemcooil.com/specials.php

Yeah, i already knew that lead is a benefit to 4 strokes but wasn't sure about 2 strokes. it's good to know that it won't hurt my engine because it seems that all of the higher octane gas that i can get around here is leaded.

thanks for the response. It was very helpful.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

  • Similar Content

    • By Nicturner
      Hi fellow thumpers,
      firstly if there is other threads on this topic I apologize.
       
      i have a 2009 KTM 450 exc. I live at 5500 feet. I have a keihin carb. I currently have it set up with 
      green needle (jd kit) @ 4th from the top
      main #175 
      pilot #42
       in setting it up for some desert riding I plan on doing next month (LAB2V). Right  now I’m getting a bog if I rack the throttle a few times. I’m reading this is semi normal as the accelerator pump has a hard time refilling.
      i have put a new diaphragm, spring, lean jet is at #40 and air fuel acre 1 and 1/8 out.
       
      im planning on going back to 172 main, red needle 5th from the top and #45 pilot.
      i normally ride the trails around lake arrowhead and Big bear in California. The trails are single track from 5000-10000 feet.
       
      Anyone see any issues with either set up?
      how about the big if I get on it a few time ( not really noticeable when riding)
      sorry for the questions. This is my first carb I’ve ever worked on. 
       
      Thanks in advance 
       
    • By SNORE125
      Anyone else have 130 main and 38 pilot jets already in the carb I took the wifes ttr 230 carb apart to add the bigger jets and this bike from 05 that I bought new already had them in it? I was reading that they came with a 125 main and a 36 pilot.
    • By Charles Joseph Miron
      Hello all.  Need a helping hand here..  
      I bought an older TT225 and am not about to spend almost $600 on a new carburetor for it. So I'm hoping someone can help me out with an idea of what (other than original carburetor) style, type and brand I should go with..  I'm also having a bit of trouble finding info on this bike.  It's a 1986 Yamaha TT225.  
      Thank you in advanced
      Charles
    • By Br0ck
      Hey guys, I went on vacation all summer and let my bike sit (2002 CR250). When I got back I ripped it apart and cleaned carburetor and put it back together and it started fine and ran alright, but idled really high. I adjusted the idle screw and realized it was a ridiculous amount of turns out. I can't remember exactly how many but id say 6+ turns out. My killswitch was a POS and didn't work anymore so I replaced it with an oem replacement. My last ride I crashed the bike pretty bad and I was off the bike for 2 weeks. I can't get the bike to start ever since I got installed the new killswitch. I think I wired it right I just replaced one wire at a time and it looked pretty straight forward. I verified it by testing spark while holding it in I was getting no spark but with it in running position it would spark. 
      Anyway I am just looking for some base settings for the Mikuni TMX to get my bike running again, my carburetor has a 35 Pilot and 380 Main jet which appear to be stock. I am located in Edmonton, AB, Canada which is about 2500ft and usually ride between 10-25 celcius.
      Thanks for any replies. 
    • By Goon Rides
      Hey guys... so I have a problem... I took the bike at Cal City, broke it in, and while I was doing so, the bike was bogging in first gear (Yes, first gear). Also it doesn't idle at all. I have to keep blipping it otherwise it'll stall. So I adjusted the screw circled in image 1. Well I was listening to the sound of the of the bike, yet the rpm's weren't increasing, and it was still stalling. So then, I unscrewed the screw in image 2, well I found out that it was fully twisted to the right. So then, I twisted it to the left, still nothing; it was still stalling... where's the idle screw? I am sure that the screw in image 1 is for the air/fuel mixture screw, and the screw in image 2 is the idle screw, just broken? I don't know, any and every help would be appreciated.


×