New Yamaha yz 125 gas/oil mixture for break-in

blaze 57
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3/8/2021 6:47pm
Owners manual says 15-1 mix for the first tank and then 30:1 after break-in.. In my past 2-strokes 125's I always mixed 32:1 for the life span. Is 15:1 required? thanks
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Bruce372
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3/8/2021 9:23pm
Just use what you normally use. Break in is over rated
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boothead359
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3/8/2021 9:48pm
Yes that is correct. All new bikes require a break in, tho the procedure varies from one manufacturer to another. The extra rich 15-1 ratio is just for the first hour. Yamaha ya says 20 min at 1/2 throttle max then 40 min at 3/4 throttle max. After that I would be comfortable running 32:1, that is so close to 30:1 that you prolly wouldn’t even see the difference in your measuring device. You gotta figure after all these years Yamaha motor Corp has a pretty good idea how to break their bikes in properly. Good look and enjoy your new bike
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FGR01
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3/9/2021 5:27am
Do the 32:1. Don't do 15:1. There have been guys that have seized their pistons following Yamaha's extra oil for break-in guidance. Richer oil:gas ratio = leaner gas:air ratio.
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blaze 57
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3/9/2021 8:57am
FGR01 wrote:
Do the 32:1. Don't do 15:1. There have been guys that have seized their pistons following Yamaha's extra oil for break-in guidance. Richer oil:gas ratio =...
Do the 32:1. Don't do 15:1. There have been guys that have seized their pistons following Yamaha's extra oil for break-in guidance. Richer oil:gas ratio = leaner gas:air ratio.
Thanks I go with that. All my past 2-stroke 125's were all broke in with 32:1 and never an issue. This is the first time I have seen this and exactly this bike was obviously jetted for 32:1 so no way would I want to lean it out.
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kevinr
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3/11/2021 10:30am
We just broke in a 2021 yz85 on 32:1. My brother-in-law broke in 2 2019 YZ65s with the 15:1 ratio and the bikes have never been good. They foul plugs every ride, not to mention the dozen plugs he went through during the break in.
DynoDan22
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3/11/2021 6:27pm Edited Date/Time 3/11/2021 6:28pm
I wonder what oil ratio Yamaha uses when they dyno every bike, wide open too see if it passes the go-no-go power test? Yes, every bike that comes off the assembly line is strapped to a dyno and strangled to see if it meets the +/- tolerance on peak horsepower. Look at every new motocross bike on the floor and you will see wear marks on the rear disk from the dyno run. Zero marks on the front rotor. The best break in is to check all fluids, air filter and all critical bolts. Warm up until radiators are very warm. Ride at 50% and don't huck massive jumps in case the transmission is notchy. Ride for 10-15 minutes, recheck fluids and bolts and let 'er rip.
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boothead359
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3/12/2021 7:40pm
Yep. You guys are right. I guess every Yamaha dealership in the country and Yamaha themselves, despite the millions of dollars in r and d money , and the hundreds of thousands of motors that Yamaha has produced , well they really just don’t know what they’re talking about. That experience can’t begin to compare to the wealth of knowledge amassed by a hillbilly in his garage that has owned a dozen bikes , a few of which may have been purchased new. Why would you not heed the advice of a corporation that has been so successful and produce the product they’re advising you on. I’ve owned 2 new bikes, and followed manufacturers procedures with both, and both were different processes.
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FGR01
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3/12/2021 8:01pm
Yep. You guys are right. I guess every Yamaha dealership in the country and Yamaha themselves, despite the millions of dollars in r and d money...
Yep. You guys are right. I guess every Yamaha dealership in the country and Yamaha themselves, despite the millions of dollars in r and d money , and the hundreds of thousands of motors that Yamaha has produced , well they really just don’t know what they’re talking about. That experience can’t begin to compare to the wealth of knowledge amassed by a hillbilly in his garage that has owned a dozen bikes , a few of which may have been purchased new. Why would you not heed the advice of a corporation that has been so successful and produce the product they’re advising you on. I’ve owned 2 new bikes, and followed manufacturers procedures with both, and both were different processes.
OK, so riddle me this. Do you think the various Yamaha factory teams even followed that 15:1 guidance with their own bikes?

Have you ever spoken to the actual engineers from the Yamaha factory that designed the YZ engines about the topic of break in on new YZ 2-strokes? I have. Summary - what you read in an owner's manual is not necessarily there because the people who designed the bike actually think it's required. Ever read some of the ludicrous things like "remove piston after 1 heat cycle, inspect for score marks and remove as needed".

At the end of the day, by your logic we should change the name of this forum to "owner's manual quotes" and just sit here passing owner's manual info back and forth. Or maybe we could split it in two and have an owner's manual quote subforum and a Hillbilly knowledge subforum.
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skypig
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3/12/2021 9:13pm
There is sometimes a conflict between “saving warranty claims”, and “Best practice”.

With the KTM 690 engines, KTM would say “break it in gently. Idling is OK, etc”
This would often lead to terrible “Ring seal” - high oil consumption and reduced performance. But guess what? KTM would just declare “insane” oil consumption as “within spec”. (From memory 100ml/1000km was “ok”). So no claim.

The gentle break in was surly better for cams etc, and less likely to cause a warranty claim. Evenif the engine was a bit “marginal” to begin with, but no enthusiast (the only people who buy these bikes) would be happy with the result.

If I was paying for warranty claims on YZ125s, I’d recommend rich jetting and 15:1 for break in. Then rich jetting and 30:1 from the second tank. Plugs and “oiled up” engines aren’t warranty claims.

If I had a YZ125, I’d run it in with the stock jetting and 30:1. I would ride it as intended, and avoid idling at all costs, and constant light loads as much as possible. Then try for the best jetting I could find. (Probably leaner than stock)

It’s your bike - do what you want.
kevinr
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3/15/2021 11:00am
skypig wrote:
There is sometimes a conflict between “saving warranty claims”, and “Best practice”. With the KTM 690 engines, KTM would say “break it in gently. Idling is...
There is sometimes a conflict between “saving warranty claims”, and “Best practice”.

With the KTM 690 engines, KTM would say “break it in gently. Idling is OK, etc”
This would often lead to terrible “Ring seal” - high oil consumption and reduced performance. But guess what? KTM would just declare “insane” oil consumption as “within spec”. (From memory 100ml/1000km was “ok”). So no claim.

The gentle break in was surly better for cams etc, and less likely to cause a warranty claim. Evenif the engine was a bit “marginal” to begin with, but no enthusiast (the only people who buy these bikes) would be happy with the result.

If I was paying for warranty claims on YZ125s, I’d recommend rich jetting and 15:1 for break in. Then rich jetting and 30:1 from the second tank. Plugs and “oiled up” engines aren’t warranty claims.

If I had a YZ125, I’d run it in with the stock jetting and 30:1. I would ride it as intended, and avoid idling at all costs, and constant light loads as much as possible. Then try for the best jetting I could find. (Probably leaner than stock)

It’s your bike - do what you want.
I agree. I was just giving what my personal experience was with 3 brand new yamaha 2-strokes that were broke in different ways.

Both have stock jetting and were broke in at the same elevation setting. Using the 15:1 the bikes consumed at least a dozen plugs and seem to continue to do so even a year later on 30:1.

The bike that went straight to 32:1 is running great so far on OEM plug (it's also ridden harder so that could be a lot of the issue).
MR289
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1/10/2022 7:45am
Yamaha YZ125 manual says 30:1 to many years and recommended Yamalube 2R.

BUT

Yamalube 2R up to 2018 (I think) has viscosity @40°C - 55 cst @100°C - 8,5 cst @150°C - 3,56 cst @200°C - 2,00 cst
Yamalube 2R from 2018 (maybe ENEOS) has @40°C - 169 cst @100°C - 19,6 cst @150°C - 7,09 cst @200°C - 3,61 cst

So up to 2018 was 2R pre-diluted !!! Now they use pre-mix only - 100% synthetic oil with esters with almost double viscosity and no changes in manual. Link below is for catalogue Yamalube 2019. 2R recommended 50:1 same as Motul 800.

https://www.yamaha-motor.eu/content/dam/fi-esitteet/20-068_2020_YAMALUB…

So for me, if manual say 30:1 and 15:1 - with 100% synth ester base oils you can use it 50:1 and 25:1 for break-in. More viscosity stronger oil film which protect parts.

Average numbers of @100°C @150°C and @200°C OLD 2R 4,686 (30:1) if you want same number with NEW 2R you can mix aorund 60:1 with same result. First number @40°C is not critical in this application because cylinder head temperature is around 200 - 240°C (water cooled).

So why Yamaha do not change manual numbers when change Yamalube 2R supplier?
murph783
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1/10/2022 9:39am
DynoDan22 wrote:
I wonder what oil ratio Yamaha uses when they dyno every bike, wide open too see if it passes the go-no-go power test? Yes, every bike...
I wonder what oil ratio Yamaha uses when they dyno every bike, wide open too see if it passes the go-no-go power test? Yes, every bike that comes off the assembly line is strapped to a dyno and strangled to see if it meets the +/- tolerance on peak horsepower. Look at every new motocross bike on the floor and you will see wear marks on the rear disk from the dyno run. Zero marks on the front rotor. The best break in is to check all fluids, air filter and all critical bolts. Warm up until radiators are very warm. Ride at 50% and don't huck massive jumps in case the transmission is notchy. Ride for 10-15 minutes, recheck fluids and bolts and let 'er rip.
Exactly this. I don’t think people understand that every bike that rolls off the assembly line has already been on the dyno and held to the wood.

Now does that count as a break in? No.

Do I break my bikes in per their recommendation? Also no. I’ve done my fair share of them, and two or four stroke I run the fuel and oil I plan on running, do a moto or two at half to 3/4 pace then drop the oil (and filter if applicable) and from there on out run it as you normally would.

Am I an engineer? No, but I’ve done every new bike I’ve owned this way, and sent hundreds if not thousands out with customers and never had an issue. That’s just what this one mechanic has seen.
Leeham
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1/10/2022 3:52pm
Yep. You guys are right. I guess every Yamaha dealership in the country and Yamaha themselves, despite the millions of dollars in r and d money...
Yep. You guys are right. I guess every Yamaha dealership in the country and Yamaha themselves, despite the millions of dollars in r and d money , and the hundreds of thousands of motors that Yamaha has produced , well they really just don’t know what they’re talking about. That experience can’t begin to compare to the wealth of knowledge amassed by a hillbilly in his garage that has owned a dozen bikes , a few of which may have been purchased new. Why would you not heed the advice of a corporation that has been so successful and produce the product they’re advising you on. I’ve owned 2 new bikes, and followed manufacturers procedures with both, and both were different processes.
Its more of a liability thing over a machine prep thing. When I picked up my 21 YZ250F, dealer told me take it easy on the first ride. No more than 3/4 throttle. I said okay then that very weekend I made sure it was fully warmed up then rode it. With how I ride is to the limiter. Bike has ran fine since then, 43 hours. Lots of rev limiter time. Bike runs because I change the oil all the time and clean air.
Moto520
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1/10/2022 4:55pm Edited Date/Time 1/10/2022 4:57pm
32:1….Yamalube R……try to use 1 gallon of race gas per 3 gallons. Ride it.

1/10/2022 5:44pm Edited Date/Time 1/10/2022 5:49pm
MR289 wrote:
Yamaha YZ125 manual says 30:1 to many years and recommended Yamalube 2R. BUT Yamalube 2R up to 2018 (I think) has viscosity @40°C - 55 cst...
Yamaha YZ125 manual says 30:1 to many years and recommended Yamalube 2R.

BUT

Yamalube 2R up to 2018 (I think) has viscosity @40°C - 55 cst @100°C - 8,5 cst @150°C - 3,56 cst @200°C - 2,00 cst
Yamalube 2R from 2018 (maybe ENEOS) has @40°C - 169 cst @100°C - 19,6 cst @150°C - 7,09 cst @200°C - 3,61 cst

So up to 2018 was 2R pre-diluted !!! Now they use pre-mix only - 100% synthetic oil with esters with almost double viscosity and no changes in manual. Link below is for catalogue Yamalube 2019. 2R recommended 50:1 same as Motul 800.

https://www.yamaha-motor.eu/content/dam/fi-esitteet/20-068_2020_YAMALUB…

So for me, if manual say 30:1 and 15:1 - with 100% synth ester base oils you can use it 50:1 and 25:1 for break-in. More viscosity stronger oil film which protect parts.

Average numbers of @100°C @150°C and @200°C OLD 2R 4,686 (30:1) if you want same number with NEW 2R you can mix aorund 60:1 with same result. First number @40°C is not critical in this application because cylinder head temperature is around 200 - 240°C (water cooled).

So why Yamaha do not change manual numbers when change Yamalube 2R supplier?
I think the new 2R is basically MOTUL 800 (at least in Europe anyway) and I think you nailed it.
Falcon
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1/11/2022 1:58pm Edited Date/Time 1/11/2022 2:00pm
Yep. You guys are right. I guess every Yamaha dealership in the country and Yamaha themselves, despite the millions of dollars in r and d money...
Yep. You guys are right. I guess every Yamaha dealership in the country and Yamaha themselves, despite the millions of dollars in r and d money , and the hundreds of thousands of motors that Yamaha has produced , well they really just don’t know what they’re talking about. That experience can’t begin to compare to the wealth of knowledge amassed by a hillbilly in his garage that has owned a dozen bikes , a few of which may have been purchased new. Why would you not heed the advice of a corporation that has been so successful and produce the product they’re advising you on. I’ve owned 2 new bikes, and followed manufacturers procedures with both, and both were different processes.
"Why would you not heed the advice of a corporation that has been so successful and produce the product they’re advising you on."

Why not? Because sometimes what is written in the owner's manual is wrong, and not what 99% of employees of that corporation, including the engineers who designed the product, know to be correct.
1
1/11/2022 10:58pm
MR289 wrote:
Yamaha YZ125 manual says 30:1 to many years and recommended Yamalube 2R. BUT Yamalube 2R up to 2018 (I think) has viscosity @40°C - 55 cst...
Yamaha YZ125 manual says 30:1 to many years and recommended Yamalube 2R.

BUT

Yamalube 2R up to 2018 (I think) has viscosity @40°C - 55 cst @100°C - 8,5 cst @150°C - 3,56 cst @200°C - 2,00 cst
Yamalube 2R from 2018 (maybe ENEOS) has @40°C - 169 cst @100°C - 19,6 cst @150°C - 7,09 cst @200°C - 3,61 cst

So up to 2018 was 2R pre-diluted !!! Now they use pre-mix only - 100% synthetic oil with esters with almost double viscosity and no changes in manual. Link below is for catalogue Yamalube 2019. 2R recommended 50:1 same as Motul 800.

https://www.yamaha-motor.eu/content/dam/fi-esitteet/20-068_2020_YAMALUB…

So for me, if manual say 30:1 and 15:1 - with 100% synth ester base oils you can use it 50:1 and 25:1 for break-in. More viscosity stronger oil film which protect parts.

Average numbers of @100°C @150°C and @200°C OLD 2R 4,686 (30:1) if you want same number with NEW 2R you can mix aorund 60:1 with same result. First number @40°C is not critical in this application because cylinder head temperature is around 200 - 240°C (water cooled).

So why Yamaha do not change manual numbers when change Yamalube 2R supplier?
I think the new 2R is basically MOTUL 800 (at least in Europe anyway) and I think you nailed it.
Yeh if not its uncanny the similarities.
Looks the same smells the same and smells the same out the exhaust
MR289
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CZ
1/11/2022 11:25pm
Similar only with Motul 800 Road, but I think it will be ENEOS. I will try to get ENEOS data :-)

Yamalube 2R @40°C 169 @100°C 19,6 @150°C 7,09 @200°C 3,61
Motul 800 Off Road @40°C 120,2 @100°C 15,5 @150°C 5,89 @200°C 3,10
Motul 800 Road @40°C 152 @100°C 18,7 @150°C 6,92 @200°C 3,56
Motul Kart Grand Prix @40°C 135 @100°C 16,9 @150°C 6,33 @200°C 3,29

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