50:1 to 40:1 question

GoldenMotor.com

slayer60973

New Member
Dec 24, 2012
96
0
0
West Michigan
Alright, I was going to wait till I ran out of gas to change ratios for summer, just for a little extra protection. But I'm impatient... lol so as most of us know 50:1 is 2.6oz per gal and 40:1 is 3.2oz per gal. I drained what was in the bike back into my gas can and I had about 3/4 gallon left. So 3.2-2.6 is .6 I then divided that by 4 for each quarter gallon, and got .15 then times that by 3 for 3/4 gallon. And got .47 or something close to it, so I added about .5 oz to get 40:1. Is my math right? If it isn't it's no big deal as tuning my bike doesn't really bother me. I do have a quick mix cup for the right mix when I get some fresh gas. Though I did snap my e clip in half that goes to the needle. (Sigh) So I have to go through my rc truck parts bag to see if I have one that fits.
 
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rogergendron1

New Member
Sep 18, 2013
882
2
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42
woburn ma
Bro it dpesnt have to be perfect lol i run anywhere from 25:1 to 32:1 depending on the oil used . I like a leaner mix like 25:1 cause it offers greater protection at higher rpms but even 50:1 would be fine for a sto,ker running low rpms just pick a good oil i sugjest running amsiol dominator .. Orde it online if you have to .

I only run 25:1 when i go out and stret race my bike in empty lots and on back roads i run 32:1amsoil dominator and add in lucas oil upper cylinder lube to make it 25:1 then swap to a larger main jet and to make up for the decrease in gas per oz and go... She runs beautifull at 85000 _ 9000 rps !!! I only run 40:1 or 50:1 when i am cruising about from a to b and keep it under 7000.
 

rogergendron1

New Member
Sep 18, 2013
882
2
0
42
woburn ma
I meam crapan if u have a stocker you could run used motor oil at 16:1 and she would still go lol but once you have put a lot of work into it and she can push her limmit in rpms oil quality and ratio becomes more important
 

mapbike

Well-Known Member
Mar 14, 2010
5,502
109
63
Central Area of Texas
In mine and most people that have been running these engines for several years now recommend first that you use a high quality oil and second use the manufacturer s recommended mix for that particular oil, the oil debate in regards to which brand is best and what is the best mix ratio will obviously never die on this forum, but if you will do your do diligence and use the search feature on this forum you wll get hours of education on what the long time runners and builders of these engines use and at what ratio they have proven to work great for them.

I run my engines @ 100:1 and I use Opti2 oil which is designed for the ratio, I run my engines hard and at high RPMs the carb needs to be precisely tuned for the oil and mix you plan to run and then you should stick with that mix always unless you retune for a different mix ratio, some of my engines see well over 9000RPM and I have actually torture tested one of them on a wide open throttle run non stop for over 7 miles, this engine still runs strong and smooth with over 500 miles on it now and it has never seen anything but 100:1 Opti2 mix

I have logged several thousand miles combined on three bikes now and they're all still running great and not a single oil related failuresince switching to using Opti2 back in 2010.

There are other good oils out there also like Amsoil, Maxima, Redline, Lucas, the Echo 50:1 synthetic blend oil is another good oil, just make sure the carb is tuned correctly and you decide on a mix and stick with it is the best insurance that you dont have oil related issues do to a lack of or to much oil which can. Ause a lean run condition that can fry your engine.

Map
.wee
 

slayer60973

New Member
Dec 24, 2012
96
0
0
West Michigan
I run klotz r50 at 40:1. R50 is designed specifically for high rpm engines. At 16 bucks a quart id say it's good oil lol. And the exhaust has a sweet syrupy smell.
 
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