Yamaha G1 Premix Oil Thread

[slonomo]

I thought I started a thread about this before, but I couldn't locate it. So, here is a thread dedicated to the 2 cycle oil premix subject for the Yamaha G1.

Disclaimer: I am not an endorser of any product listed in this thread. I do not get payment from anyone regarding oil, oil additives, or fuel treatments. This thread is intended to share information only. I do not endorse deactivating your factory oil injection system. Deactivating of your factory oil injection pump is not recommended and can have negative impacts on your engine, you do so at your own risk. If you deactivate your factory oil pump you must premix your fuel and 2 cycle oil, which can have negative impacts on your engine, you do so at your own risk.

[slonomo]

Many people ask about disconnecting or deactivating the factory oil injection system on their G1 cart. Yes, some have failed, leading to engine overheating and oiling issues and engine damage. But the reality is, they are fantastic devices, and have been used on golf carts, snowmobiles, atv's, and watercraft for years and years without issue.

Now, if you have owned your G1 since it was new, or you know it has a good maintenance history, then you probably have a good amount of confidence in your oil injection system. In my case, my first G1 cart was in pieces and did not even have an engine. So during the rebuild process I was missing lots of parts, one of them was parts of the oil injection system. In this case, I was forced to premix my fuel/oil.

Once again, I do not endorse disconnecting and removing a perfectly good oil injection system. If you have issues, or don't have confidence in your injection system then you will be forced to make a decision to premix.

I started with a fully rebuilt G1 engine, new crank, new cylinder, new piston, head gasket, crank bearings, etc.

Here is a video of me plowing snow with the rebuilt engine running premix.
https://www.youtube.com/watch?v=j2_4EyO5NsI

[slonomo]

Mixing Ratio: The factory Yamaha G1 service manual, page 8, states that the mixing ratio is 150:1 at max. power.

Oil Type: Yamalube Golf Car Oil

[slonomo]

Here is the G1 for Newbies thread
https://www.buggiesgonewild.com/showthread.php?t=76176

A tank of oil will last a long long time. The factory oil injection system mixes at a rate of 150:1 (according to the service manual). If you want to premix, as most of us did, you'll want to disconnect and remove the oil injection pump and tank so someone can't accidentally add oil and have too much oil in the fuel.

Premix ratio has been discussed on this forum hundreds of times. You will get all kinds of opinions. Here's what worked for me.

I started out with a synthetic premix oil called "Opti-2". It's a one mix fits all oil for 2 strokes that mixes at 70:1 ratio. It worked great, with very little smoke. It's expensive though. It comes in 1.8 oz packets that are designed to mix with 1 gallon containers of fuel. It can be purchased in a bottle where you have to measure it out. You see this stuff at all the small engine shops around here, it's a really good oil.

After reading the manual I started experimenting. I used "Echo" brand synthetic air cooled 2 cycle oil in the bottle. I used an online ratio calculator. I started with 50:1 and it was a mosquito fogger and left oil in the muffler. I tried 75:1 and it was better, but not as good with the Opti-2. I tried 85:1 and it was really good. I tried 100:1 and it was the best yet, no smoke and good power. I eventually went to 120:1 and that's where I kept it until I sold the engine. I have built 3 G1's with the stock engine and used 120:1 on all 3.

The original engine in my cart was run with 120:1 for years and I even disassembled it and inspected the cylinder for wear.....almost no wear! I could still see the cross hatch pattern, it looked new. So I knew it was a good ratio for long term use. And I ran the snot out of that little engine. I even had a 250 Enticer snowmobile top end on it for a while that ran 7000 rpm.

So, my vote is Echo brand air cooled 2 cycle oil premixed at 120:1 with good non ethanol fuel, or with ethanol treatment, and I used minimum 91 octane fuel since I ran the cart in the summer.

Note: Make sure the oil you use is "Synthetic air cooled 2 cycle oil" and not "marine 2 cycle oil" there's a huge difference.

Note: If you use an ethanol fuel treatment, Lucas and Stabil make really good products. Stabil will also stabilize your fuel for the winter. Just make sure it says "Ethanol Treatment".

[slonomo]

Update:

Thought it was important that I let you all know where I gained my knowledge on this subject. The 2 cycle oil trials went way beyond the G1 golf cart. For many years I ran and operated a landscape maintenance business, and worked in the industry for quite a long time. I have used weed trimmers, blowers, chainsaws, snow blowers, push mowers, and hedge trimmers, all 2 strokes. I've used Toro, Echo, Stihl, Lawn Boy, Poulan, and Husqvarna. With all those machines and brands I have used a multitude of fuels, additives, and oils. This is where I collected my knowledge and experience. I also worked in the auto parts industry for a long time and attended training seminars regarding oils. In no way am I an expert, I just know a little from my experience in these industries. Please do your own research.

I did forget to add one to the list. For years I was an Amsoil guy and ran it in my diesel truck etc. Well, I forgot that I used their 2 cycle oil in my G1 for a while.

Amsoil Saber is good stuff, not that expensive either, although it's on the high side of the list. It's ratio on the bottle calls for 80:1 - 100:1 for all two stroke engines.

Another update is I see that Echo has changed their oil formulas. They no longer say "synthetic" on the bottle. Back a few year ago they had an option for regular and synthetic oil. I chose the synthetic and it had ratios up to 100:1 listed on the bottle, it worked well for me then. At this point I can't speak for the "new Echo" oils on the market in 2020.

Disclaimer:
Before you start premixing your fuel/oil, read the label on the oil you want to use. Some oils, usually non-synthetics, will recommend 25:1 or 50:1 for all engines. If you see this, DO NOT USE THAT OIL. That means that particular oil does not contain the correct formula of compounds to be able to run at ratios like 80:1 and 100:1. Instead, find an oil that is synthetic and has 100:1 listed as a recommended ratio. The Opti-2 and the Amsoil Saber both will work at those ratios, according to their literature and packaging. The Opti-2 3.2 oz packets are designed to mix with 2.5 gallons of gasoline, making 100:1.

[slonomo]

What are the issues with running ratios like 50:1, or ratios with more oil than 150:1?


1. Lots of smoke from the exhaust. Most 2 strokes will smoke a little. All 2 strokes will smoke a lot if you use too much oil. A good running 2 stroke engine with the proper amount of oil in the fuel, and good clean fuel, should not smoke much at all.

2. Oil dripping from the exhaust flange. I've owned 3 G1's and rebuilt all of those engines. When I got them, they all had oil dripping from the exhaust flange and smoke would bellow from the engine compartment when the cart was first started. The oil would burn off eventually. I found that low rpm driving would cause more oil to build up in those engines. Now, that could be a result of a worn out engine, but I also believe the oil injector system was either not working or the wrong oil was used. Once I premixed at a better ratio like 100:1, no oil, no smoke.

3. Oil build up in the exhaust. The G1 muffler seems to collect unburned oil inside the exhaust. Most of this is from years of low rpm driving and short distance driving. The exhaust pipe/muffler never gets a chance to heat up enough to burn the oil off. The cause could also be....too much oil or the wrong kind of oil. Once you correct the oil ratio, you can take the cart on a nice long drive to help burn that oil off. Some people will "BBQ" the muffler to burn off the oil residue, which I've heard works well. There are BBQ threads on the forum.

4. Low power. Adding more oil to the fuel means that per ounce there is less fuel. Granted, it's not much, maybe 1-2%. Nonetheless, more oil means less power.

5. Crank seals wet with oil. This is more of a problem with worn crank seals, but if you have worn seals you'll see a lot of oil coming from that area, if your ratio of oil is high. A lot of times carts run like this for years will have such a huge amount of dirt/oil build up near the seals that it's very obvious. Running less oil WILL NOT fix the worn seals, but it will cut down on the amount of oil coming from them.

6. Spark plugs will foul out. Too much oil in the cylinder means the spark plug gets exposed to that oil and the carbon that is produced when it's burned. It's inevitable. Two strokes need new spark plugs more often than 4 strokes, it's just a fact. With that said, if the fuel has too much oil in it, you will likely foul the plugs out much faster, and they might even tend to be oily. A fouled spark plug can leave you stranded.

If any of you can add to the list, please do.