Gas in my oil-Hawk

[o2jmpr]

I'm having a problem I need your input on.

I just did my first oil change after the initial break in period at 200 miles. I did one before ever starting it, another at 30 minutes of run time and now this one.

I can easily smell gas in the oil and the viscosity of the oil is too thin. (I'm using 15-40 Rotella). I changed the oil and ran it one more time for about 10 minutes, shut it down and turned the petcock off and let it sit for three days and I can smell gas still when I pull the dipstick.

What is causing this?

I always shut off the petcock and I'm at ~900ft altitude running a 110 main jet and the stock Sheng Wey 20 pilot with the mixture 1.5 turns out.
It runs wonderfully. It starts right up and idles well with no choke. The only thing I can tell at all is that the pilot must be a tad small because I get just a bit of popping when decelerating, but it's not awful.
I just checked the air filter too and I can see VERY small amount of oil from the crankcase in the air box but its only on the bottom, not the walls and the filter is perfectly clean and dry.

HELP!!! I don't wanna blow this thing up!

Thanks everyone!

[Sochin]

Only think I can think of this happening, is if the float gets stuck in the carb
. But you say you are careful and shut the valve? Hmmmmmmh

[Megadan]

Are you seeing a noticeable increase in oil level?

With a fresh engine, you are going to have some hydrocarbon dilution with the oil. This is one reason why I changed the oil on my bike no less than 7 times from initial break in to the 1000 mile mark. The first few always had a smell of fuel to them, but that has slowly reduced as I have racked on the miles.

This can be amplified by having a too rich main jet or needle jet setting - even slightly too rich. The way you have your carb setup now is kind of the baseline that many people go with, but it is a good idea to try and fine tune the jetting to your altitude and climate. On a completely stock bike many people have run a 105 main jet with success below 1000ft.

Also, if you can start your bike dead cold without any choke at all, it is usually a good indication that the pilot jet is too big or the idle mixture setting is too rich. However, since you have the stock pilot, that rules out the former, and 1 1/2 turns on the mixture screw is likely not too rich given the stock pilot size (still a good idea to actually tune your idle mixture). I am almost wondering if your float height is a little too high.

The seemingly watery oil on the oil change, if you changed it hot, is normal - especially with aircooled engines. The oil absorbs a lot of heat along with the normal abuse it sees.

[o2jmpr]

You guys are the best! I always get better support on this forum than I ever have in a brick and mortar shop. I REALLY appreciate your knowledge!

Ok Megadan, you've helped me out with perfect solutions to a few problems in the past so I feel much better about this now. I DO believe I'm rich on the main jet, I just didn't think enough to cause problems. There is absolutely not enough gas to raise the level, the oil still feels like oil, it's just noticeably thinner. The gas smell is pretty faint. My wife is like a bloodhound when it comes to smell and she had to do a double take to notice the gas the last time I ran it for 10 minutes after a fresh oil change. Still, I know it can't be good to be running the engine in that condition too hard or too long. I've never had a new bike before this one where I was the one to seat the rings either.

Like you say, It will fire right up and idle dead cold with no choke. I have two scrap washers under the needle. Should I try a 105 main first or try removing a washer first, or do both???
The one thing I HATE about this bike is there is no way to adjust the mixture while the bike is running without a special bevel screwdriver or buying one of those replacement hand-turn adjusters. I honestly just went with 1.5 turns out because it seemed middle of the road but the mixture is not tuned perfectly for my engine.

I can check my float but I've never adjusted one before. I assume it should sit level when turned upside down right?

[Ariel Red Hunter]

You guys are the best! I always get better support on this forum than I ever have in a brick and mortar shop. I REALLY appreciate your knowledge!

Ok Megadan, you've helped me out with perfect solutions to a few problems in the past so I feel much better about this now. I DO believe I'm rich on the main jet, I just didn't think enough to cause problems. There is absolutely not enough gas to raise the level, the oil still feels like oil, it's just noticeably thinner. The gas smell is pretty faint. My wife is like a bloodhound when it comes to smell and she had to do a double take to notice the gas the last time I ran it for 10 minutes after a fresh oil change. Still, I know it can't be good to be running the engine in that condition too hard or too long. I've never had a new bike before this one where I was the one to seat the rings either.

Like you say, It will fire right up and idle dead cold with no choke. I have two scrap washers under the needle. Should I try a 105 main first or try removing a washer first, or do both???
The one thing I HATE about this bike is there is no way to adjust the mixture while the bike is running without a special bevel screwdriver or buying one of those replacement hand-turn adjusters. I honestly just went with 1.5 turns out because it seemed middle of the road but the mixture is not tuned perfectly for my engine.

I can check my float but I've never adjusted one before. I assume it should sit level when turned upside down right?Yes, the float should be the same height above the float bowl rim on both ends of the float when you hold the carb body upside down. The other possibility is a small foreign substance in the needle or seat where the gas enters the float bowl. That will cause the same problem...ARH

[o2jmpr]

Since it runs so well as is, I think it makes sense to just check my float/needle/seat and maybe turn in the mixture an 1/8 to 1/4 turn and reassemble and keep riding it while doing 100 mile oil changes to see if it dissipates on it's own until ~1000 miles or continues. I can change the main jet and remove washers later if needed.

[Megadan]

Concerning the main jet and washers/shims. Do one, or the other and see how the bike reacts. The main jet size will somewhat affect the needle side of things as the main jet fuel flows through the same orifice that the needle regulates. Between the two, I would say leave the needle where it is and try the 105 main. It doesn't take long to swap the jets, and if you do it enough you get really good at doing it quickly (I changed jets probably 15 times between stock and modified tuning).

There is a lot of information on here about carb tuning, but I am more than happy to lend some advice. Biggest piece of advice I can give is simply do one change at a time so you can note any changes. Tossing too many variables into the mix makes it hard to determine where, if any, good or bad results come as a result.

Taking the time to fine tune the carb is worth the effort, if a bit tedious and annoying.

[o2jmpr]

Thank Megadan. I had no intention of messing with multiple components at once. That would be a real mess! :)

I haven't done anything yet but rode the snot out of it today. I'll definitely check my float and run the mixture in a bit as mentioned before and then just keep an eye on it before I even try a new jet.

Thanks much again!

Maybe since you're so close, I'll just deliver my bike to you in the future for expert tuning. :)

[Megadan]

Thank Megadan. I had no intention of messing with multiple components at once. That would be a real mess! :)

I haven't done anything yet but rode the snot out of it today. I'll definitely check my float and run the mixture in a bit as mentioned before and then just keep an eye on it before I even try a new jet.

Thanks much again!

Maybe since you're so close, I'll just deliver my bike to you in the future for expert tuning. :)

I actually don't like tuning carbs that much lol

[pistolclass]

Maybe since you're so close, I'll just deliver my bike to you in the future for expert tuning. :)

I'm going to have my next bike delivered to Dan's house. :)

[Megadan]

I'm going to have my next bike delivered to Dan's house. :)

Sounds like I need to start a chain of chinabike shops....

[Ariel Red Hunter]

Sounds like I need to start a chain of chinabike shops....Actually there is a good business opportunity here with China bikes, Hawks in particular. A parts warehouse, centrally located. Like in Omaha, Nebraska!!...ARH

[JerryHawk250]

Sounds like I need to start a chain of chinabike shops....

China Dan's Motorsports :tup: