YT125 Fuel Consumption Question

[Tri-Motor]

Ok so I got my 125 engine back together and was curious to what kinda fuel mileage other 125 owners get. I went on a 45 minute trail ride with my friend who has a Honda 125M. The temp was -7F and filled the gas tank about an inch from the cap and topped off the oil tank, then let it warm up for 10-15 minutes. The trail we were on is packed down and had no problems in the soft snow the we ocassionally hit. I rode in 3rd gear most of the time but shifted down to 2nd a couple times and never ran the engine over half throttle. When I got back and parked it I checked the gas and it down about 2 inches from the filler rim. I was sorta surprised. Is this normal fuel consumption for these?

[Highhorse78]

That sounds about right for fuel usage, as these things sip very little. For comparison, I had a 1980 DT125 that got about 32mpg in town or in similar conditions. All depends on climate, jetting, and rider though. Have you went up a couple main jet sizes for the colder weather? Also if you're looking to extend your fuel range and your machine is an 83 and later with the vented tank shroud, you can go with the two piece YT175 tank that is .4 gallons larger in size.

[barnett468]

i don't have that specific model but have ridden several street bikes and atv's in that cc range and in my experience your usage sounds typical and good as mentioned above. in other words it is not excessive.

i would also check the plug color to see if the jetting needs to be changed as suggested above.

also even though you did not ask, i would suggest you run around a 5w - 30 oil in those cold temps if your current oil is heavier than that. this should also be mentioned in your service manual.

in addition, i would run one specifically designed for motorcycles that also had high levels of zddp in them [which many do] and you might consider a synthetic if your engine is already broken in.

[barnett468]

Your response to the new guys fuel consumption question also you tell him to use 5w30 oil. You do realize as a big shot engineer that a yt125 is a 2 stroke.

I just received the message above referencing your thread [post], and it seems confusing to me.

I think the sender might have meant to post it on your thread and somehow accidentally posted it to me, therefore I am posting it here on his behalf.



It is my “guess” that the sender is either wanting you to know that you have a 2 stroke engine or is implying that a 2 stroke motorcycle engine does not have a transmission and therefore does not need transmission oil.

They may also be confused because I did not specify that my oil suggestion was for your transmission and therefore might have thought I was recommending that you mix it with your gas.

To clarify my post, the oil recommendation I gave you was for your transmission. I based my post on the “guess” that you and anyone else reading it would automatically know this by the simple fact that I suggested a multi viscosity oil. They do not make multi viscosity oils for the purpose of mixing with gas to power a 2 stroke engine.

I felt compelled/obligated to post this clarification after reading the message quoted above. It is done for the benefit of anyone that might not understand exactly where I intended the oil I suggested to go, and NOT because I thought in any way that you, Tri-Motor [the op] might not understand my post.

I apologize if you and/or others did not clearly understand where I intended you to use the oil I recommended.



The mfg’s recommendation for transmission oil in the Yamaha YT 125 – G, H J, K, L and N and YT 175 – J and K is SAE 10w-30 API SE. This is stated on pg 370 of the condensed factory service manual in link below.

This viscosity is recommended for temps above around 40 degrees.

They no longer make API SE oil however it has been superseded by other oils.

http://www.oscarmayer.net/atc/manual...rvice-data.pdf



PURPOSE OF ZINC – Many are under the misconception that ZDDP is only “needed” to protect the cam and lifters in a flat tappet cam engine. It is actually one of the best “lubricants” for protecting any metal where there is moving, metal to metal contact and which is also under high pressure. In ALL motorcycle engines this high pressure includes the transmission gears, especially when they are shifted under load. This is because there is extreme force on the cogs as they slide on the mating gear surface and also as they slam into the mating gear as it is shifted at WOT.

The following is an abbreviated excerpt from an article by Valvoline. See the complete article in the link below it.

• What is motor oil with zinc?

The anti-wear additive simply referred to as zinc by most car enthusiasts is actually short for Zinc DialkylDithiophosphates or ZDDP. Its primary role is to prevent metal-to-metal contact between engine parts by forming a protective film.

http://www.valvoline.com/faqs/motor-oil/racing-oil/

[barnett468]

Hello Tri-Motor;


Please excuse the grammatical errors in my post above, I am unable to correct them because I do not have an edit button.

The message I received that I quoted in my post above was the complete text I received and was not abbreviated or edited by me in any way, therefore I am not responsible for it's content or any grammatical errors it may contain.

[muthey]

It's OK barnett468 most non 2 strokers don't know about the transmission oil, and a lot of the new 2 strokers don't realize that all the way up to the early 80's actual motor oil was used with the gas mix instead of special 2 stroke oil. But as to the original question, yes that is normal fuel consumption to the type of riding you have described. I second checking the color of your plug tip to see if you need to re jet or adjust your mix screw

[dougspcs]

Your EDIT button was taken because you are a back-tracker Barnett..deleting things and saying you never said them is just who you are.

Fess up..a lot of techno babble to just disquise the fact you didn't know the YT125 was a two stroke!!

[barnett468]

From post 3.

also even though you did not ask, i would suggest you run around a 5w - 30 oil in those cold temps if your current oil is heavier than that. this should also be mentioned in your service manual.

From post 4.

The mfg’s recommendation for transmission oil in the Yamaha YT 125 – G, H J, K, L and N and YT 175 – J and K is SAE 10w-30 API SE. This is stated on pg 370 of the condensed factory service manual in link below.

http://www.valvoline.com/faqs/motor-oil/racing-oil/

From post 7.

Fess up..a lot of techno babble to just disquise the fact you didn't know the YT125 was a two stroke!!

From post 5.

It's OK barnett468 most non 2 strokers don't know about the transmission oil,

My interpretation of the oil comment in the post from another member above, suggests to me that you appear to be right muthey, however my interpretation could be wrong.

Tri-Motor, since the oil suggestion I made in post #3, does in fact closely match the oil recommendation in the "condensed" original service manual I posted the link to for you in post #4, it would, imo, seem reasonable for virtually ANYONE to assume that I did in fact know your bike was a 2 stroke.

Irregardless, even if I did not know it was a 2 stroke, this point seems irrelevant since a 2 stroke motorcycle engine that has a transmission can use EXACTLY the same transmission oil in the transmission as most 4 stroke motorcycles that have a transmission. A few exceptions to this are when a motorcycle has an automatic transmission like the newer Honda Gold Wing and Honda CTX 700 or separate transmission like most if not all non Sporster model Harley Davidsons etc..

Again, as I mentioned in post #4, I am "guessing" you understood what I posted post #3 and therefore I am simply posting this for the benefit of others that still, even after reading my second post, might not understand them, or even muthey's post.

Your EDIT button was taken because you are a back-tracker Barnett..deleting things and saying you never said them is just who you are.

Even though the entire post above is WAY off topic, and has NO information related to your question in even the REMOTEST way, imo, it’s important I clear this up for you as much as possible and sincerely apologize in advance for the topic drift which I did NOT initiate. All I did was post some suggestions I thought might interest you.

The statement above is FALSE, I have never deleted anything and then said I never posted it. I also have not had an edit button for around 10 months, therefore it’s impossible for me to do what I am being accused of doing, lol. There is also NO proof of this EVER occurring, which is simply because it never did, irregardless of what ANYONE might tell you. I have however, seen others do this. This is just one of the reasons I “quote/copy” some posts.

I don’t “need” an edit button now nor did I ever. It’s simply an annoyance to others that I don’t have one. I also do not EVER want one, so any statement’s like the one above can CONTINUE to be proven FALSE.

I have also never complained about not having an edit button and the only reason I mentioned it, is so you, or those op’s whose threads I post on, know why I make additional posts from time to time.


PS – I hope your holidays are safe and happy.

[barnett468]

Hello Tri-Motor;

I would also like to make it clear that I, in no way, consider myself one of the foremost experts on oils, therefore I suggest that if you want to get further facts regarding oils and additives, you read some of the info on some of the major mfg’s sites like Amsoil, Motul, Lucas and Valvoline etc..

I suggest you do not get your information from Mobil 1 because some of their comments tend to contradict comments from other major oil mfg’s like the ones I mentioned who have proven some of their statements through actual testing.

[dougspcs]

Barnett, I'll attempt to make a suggestion in hopes that will be heard, you'll get alot less friction from other members about your thread jacking and mega posts and become a much more valued and appreciated member of this forum!!

Please, respond to the OPs questions with directly relavent information and perhaps in one paragraph or less!! If the OP didn't ask about oil, then a 8 paragraph technically detail post has no business here at all..do you not agree?

If you lack the directly relevent information, please refrain from posting..other members have good information also. Allow them to share it..the OP will get much more benefit from their thread!

You clearly have a lot of good information to share..what you lack is a filter!

Instead of apologizing for "topic drift"..STOP!!

This is a genuine suggestion made with no ill intent..hoping to help you integrate into this environment better.

As much as the drama does make for an interesting read, it does create ill feelings and a headache for the moderators..please hear this!

[dman]

It sure makes for entertaining reading!

[Tri-Motor]

Well I'm glad to know the fuel usage is normal. I'm used to the Honda 110's I've had which are fuel sippers compared to this. My plug is a nice tan color and even with the cold snap here it always fires up on 2-3 pulls with full choke. Right now I have 10W40 in the transmission but read that lot of people up type F ATF and was thinking about switching to that instead of motor oil. Any thoughts on that?

[barnett468]

My plug is a nice tan color and even with the cold snap here it always fires up on 2-3 pulls with full choke.

Sounds good to me.

Right now I have 10W40 in the transmission but read that lot of people up type F ATF and was thinking about switching to that instead of motor oil. Any thoughts on that?

Since you do have questions on oil I abbreviated my previous posts for you and pasted them below.

In short:

Automatic trans fluid is designed for automatic transmissions and not engines, you "can" run it but I would advise against it. Just because someone might say they ran it for years doesn't mean it is the best choice.

Automotive engine oil is designed for automotive engines, it can certainly be run in a 2 and 4 stroke motorcycle with an integral transmission like yours, and is a better choice than auto trans fluid imo, but is not the optimal choice.

Using an oil designed for motorcycles with a "wet clutch system" and integral transmission like yours is the best option. They are available at motorcycle shops and many auto supply stores.

Synthetic motorcycle wet clutch oils are also good oils to run and some prefer them in cold weather. Below is a partial list. I think Royal Purple might make one also.


Lucas

5w-20 synthetic has zddp, call for levels.
5w-30 synthetic has zddp, call for levels.

https://www.lucasoil.com/products/di...id=16&loc=show

Lucas 5w-30 synthetic motorcycle oil with ZDDP 1 qt bottle

$7.25

http://www.ebay.com/itm/like/320334863523?lpid=82


$8.99

http://www.amazon.com/Lucas-Oil-1004.../dp/B001DKQ4HO


Lucas products msds list

http://www.lucasoil.ca/products/motorcycle-products.asp



Motorex Pro 4t

5w-30 synthetic with zddp, call for level.
10w-30 synthetic with zddp, call for level.

http://www.motorexusa.com/musa/offroad.asp

http://www.ktmpartsonline.com/accessories/motorex-oils[/QUOTE]




From post 3.

also even though you did not ask,i would suggest you run around a 5w - 30 oil in those cold temps if your current oil is heavier than that. this should also be mentioned in your service manual.

in addition, i would run one specifically designed for motorcycles that also had high levels of zddp in them [which many do] and you might consider a synthetic if your engine is already broken in.

From post 4.

The mfg’s recommendation for transmission oil in the Yamaha YT 125 – G, H J, K, L and N and YT 175 – J and K is SAE 10w-30 API SE. This is stated on pg 370 of the condensed factory service manual in link below.

This viscosity is recommended for temps above around 40 degrees.

[brd812]

You can if you want, most people that run type f run it in manual clutch trannies. It's a thinner oil and has some nice properties for clutch plates. I run it in banshee and change it often. I would stick to motor oil, I don't think you need to worry about burn plates or slippage with your tri moto.

[RIDE-RED 250r]

Automotive engine oil is designed for automotive engines, it can certainly be run in a 2 and 4 stroke motorcycle with an integral transmission like yours, and is a better choice than auto trans fluid imo, but is not the optimal choice.

Using an oil designed for motorcycles with a "wet clutch system" and integral transmission like yours is the best option. They are available at motorcycle shops and many auto supply stores.

The YT125 Tri-moto is a 2-stroke and the "engine oil" is for the transmission only. It does not have the integral transmission you speak of. The engine portion is lubed via oil injection (if it is still functional)

Just to clarify.....