Oil Gas mix?

[MAPEX]

Hey guys,

I just got my 81 srx back togther and finally running...it's smokin a bit more than I wanted and seems to be pushing alitte too much oil through the pipes. So I'm thinking maybe my mix is off, what are you guys running in your sleds? Thanks

Mike

[Undertaker#13]

I run YAMALUBE &VP RACING FUEL at 40:1. I have premixed my VMAX for 19 years. I unhitched the oil injection. Yamaha rep told me years ago not to trust that system!

[Bob Vehring]

Not sure what "back together" means, if it means you put new pistons and/or rings in it, it might just need to have the rings wear in and seal up. Thats assuming everything was done right.
I agree that 40/1 is fine and Yamalube is also fine for a trail sled

Oil inj. is ok for my wifes crusier, but nothing of mine will ever have it

[Vmxhunter]

In all my vintage sleds that I had rebuilt (1982 Kawasaki Interceptor 550, 1980 Kawasaki Invader, 1981 Yamaha SS440). All those sleds had the oil Injection hooked up. And the first tank of gas on break-in. I mixed the gas 40-1 along with the injection. Boy you talk about smoke!!!! But at least I knew the motor was going to be broke in good. And I never fouled any plugs during those times.

[vmax-540]

I agree with Vmxhunter both my sleds have the injection hooked up and I have never had a problem that was caused by the injection,nor have I seen one of these sleds go down because of one.

[Bob Vehring]

Do any other sleds have the system used on the ( at least) "83, where the oil is injected before the carbs?

I have two groups of sleds, some older ones that are completely stock and I have grown to trust the factory set up.
I also have a couple hot rods, the V Max will join this group.. They have EGT gauges, I jet for the day, and I like them on the edge. As I see it, the possibility exists with the variable injection coming before the float bowls, to be crusing for a while with a lean oil mix, then when you get on it hard, you have at least some period of time where you running on very lean oil.
I love building an engine the first time, I hate doing it a second time.

[Vmxhunter]

Well I'm not up on all the motors out there. But I do know that some need the oil injection to lube the center bearing on the crank shaft (some brands). And others don't. But if your jetting lean to start with for utmost performance. Then you might want to mix your gas. If it was me..I would mix it a little heavier than normal. Since your running leaner than normal factory settup. I would mix around 30-35:1. Just to be safe. Ya, it will smoke more...but at least you'll be getting the oil.

[Undertaker#13]

I've premixed the VMAX 40;1 for 19 years and the old boy never misses a beat!

[tyler440]

this seems to be a running debate also... i too run oil injection before the float bowls and have never had an issue... premixing is not a bad idea, however i dont have the trunk space for extra oil and a cup when im out on the trail.... if i was racing then yes i would premix the couple of gallons (even less on drags) that i needed for the race... but when your trail riding, it is way too easy to just keep the resevior full

[opsled]

Hey guys,

I just got my 81 srx back togther and finally running...it's smokin a bit more than I wanted and seems to be pushing alitte too much oil through the pipes. So I'm thinking maybe my mix is off, what are you guys running in your sleds? Thanks

Mike

??? Are you premixing or using the factory injection system???

This info is needed to answer this question.

If premixing what ratio? What oil are you using? How is the sled being used? Drags, lake, trail?

You can get away or get burned depending on what you are doing with the sled.

If you are running the factory system are you sure it is adjusted properly?

If you are running it now and the outside air temps are warm it will smoke like hell. It should if it's set for cold temps.

Don't start screwing with things untill you have taken everything else into consideration. It could come back to haunt you.

opsled

PS. Yamaha invented oil injection on 2 strokes. Their systems are the best out there. The issues with injecting oil before or into the fuel pumps are nothing more than myths for trail sleds in my opinion. Vmax 540's, Exciter/ExciterII 570's, Vmax 500 and 600's, all Vmax-4's and more used this same basic system. If it were so bad Yamaha would have quit doing it. The argument could and has been made (here) that it could in fact be a better system than injecting into the manifold. Race sleds, could be a different story.

I'm not knocking the guy as it is CRYSTAL clear to me he knows his shit but, I think Tim Bender made a lot of money selling oil injection kits to guys who didn't need them.

[tyler440]

I'm not knocking the guy as it is CRYSTAL clear to me he knows his shit but, I think Tim Bender made a lot of money selling oil injection kits to guys who didn't need them.

yeah i think your probably right.... has ANYONE ever heard of an oil injection system failing? anyone? .................all i hear is crickets.....................

oh and human error does not count...

[Bob Vehring]

I agree with you guys, I have never heard of a oil inj. system failing

I ask the question regarding injecting the oil back further in the system. I'll put some more depth in my question. On my SRV I like to keep it on the edge. Getting 1200-1250 EGT on the top end is an easy thing to do. What was more involved was finding a setup for the needles and needle jets that would keep it near that range everywhere from 5000 on up. In other words, when I'm cruising along in the woods, if someone pulls up to race, or if you spot a particularly interesting section of trail, when I squeeze it, I want it right, right now, not a stumbling pig for 3 seconds. If you have to wait to get to 8K or whatever to have your jetting right, the other guy is gone.

So lets think about carb jetting. Any of the jets in a carb flow fuel, actually in this case, mixture, by volume. The book might say it flows 50-1 at WOT, I really have no idea what it flows at idle. In reality it will all depend on the settings of the cable and wear on the pump. This isn't EFI. I agree that for stock sleds, or normal people, its a wonderful thing. I fall in neither of those groups If for the sake of conversation, we consider that at any given moment, the very technical measurement of "a drop" of mixture is flowing threw that jet. Using premix, that drop is simply a percentage of gas, and a given percentage of oil. Now, with variable inj. that drop is the same volume, but because the amount of oil that makes up that drop always changes with throttle posistion, the percentage of gas available for your engine changes with it, as does correct jetting.

My original question had two parts, Does anyone see a wear issue from having the float bowls filled with a very lean oil mixture when they get on it hard. I take it, that's a No, but remember, I'm the type of anal person that pulls my pipe off once a week just so I can look at my piston The second part was, does anyone watch their EGT close enough to see a temp change as the oil ratio moves up.

I like the simplicity and convenience of inj, I think for most people its great and yes I have had a bottle of oil leak in the storage compartment of my sled.
Mine will most likely be premix, two more practical, at least to me reasons. On is simply Tyler's tag line, if you think that extra screw weights alot, you better weigh that tank, and most of all, when I open the hood, I hate extra crap in the way. I love my SRV because its NOT water cooled