03 RX1 need desperate help. Fuel in oil and more

[Claw]

Hello all. New to the 4 stroke area but not new to Totally Yamaha

I have 3 RX-1s and I really can't get them to run perfectly.
I am really close on 2 of them.

The 3rd however, I am really scratching my head and I don't want to blow the engine.
I am somehow getting fuel in the oil. Like a LOT.
The sled fires right up and sounds great. Go for a ride and the idle then goes all over the place and the oil tank fills to he top with an oil fuel mixture.
I thought the needles were stuck open, but replaced all the needles and when I have the carbs filled, I cannot blow through the hose. (not sure if this is a proven method for that)
Ive replaced the oil 3 times now and I can't keep doing that.
It also seems like cylinder #3 (if you're on the sled looking down its the 3rd from the left) is not firing properly.
I pull the wire when it running and I do not get a stumble like I do when I pull the wire to any of the other coils.
But when I pull the plug and check the spark, it fires just like the rest. So confused. Maybe its not getting fuel and thats why theres no stumble???
Ive tried 4 different coils and all do the same

Sorry for the long post. More info the better I am thinking.

Very much appreciated for any help or direction

 

[MrSled]

Usually thats a inlet needle and seat that cause that to happen or when you flood it to many times. Are you sure the choke is not partially on? I would also toss the pilots on the garbage and replace them for low end stumble.

 

[Claw]

Replaced the needle and seat on all 4.
Guess I'll go take the carbs off again and see if I can find something.
Also that carb #3 I do see some fuel sometimes shooting out the front of it.

Can't remember if I replaced the jets or cleaned originals

 

[MrSled]

Replaced the needle and seat on all 4.
Guess I'll go take the carbs off again and see if I can find something.
Also that carb #3 I do see some fuel sometimes shooting out the front of it.

Can't remember if I replaced the jets or cleaned originals

Check and make sure that choke is not sticking too.. It would be worth pulling the carbs and use a remote tank source of fuel and put them on the bench to see if the float and seats are actually stopping the fuel flow.. maybe the float is not closing due to a problem with the floats.

 

[Claw]

Great ideas.
Ill see what I can do

 

[Claw]

So I rebuilt the carbs (again) and reinstalled them.
She fired right up and sounds great.
Then I checked the oil tank and bam, it was full of fuel/oil mixture. (at least that is what I think it is)

I pulled the hoses off the top of the oil tank and fired it up again and holy sh%# the top oil breather shot out a ton of fluid.
I am loading to youtube so you can see. I will post when it's up.
What would cause that?

 

[Claw]

Or maybe it's not the breather. It is installed on the side of the breather.

I can't figure out youtube. Heres a screenshot. Its about as thin as a 50/50 gas fuel mixture

 

[MrSled]

Or maybe it's not the breather. It is installed on the side of the breather.

I can't figure out youtube. Heres a screenshot. Its about as thin as a 50/50 gas fuel mixture

Thats a return line to the tank.. thats oil and gas coming out... when you changed the oil did you drain the block and oil filter?

 

[MrSled]

Do you have this? Owner Manual for RX1? Click

 

[kviper]

Didn't the rx-1s have vacume fuel pumps? Bad fuel pump sucking fuel in to motor?

 

[MrSled]

Didn't the rx-1s have vacume fuel pumps? Bad fuel pump sucking fuel in to motor?

Thats right they do, so the one of the lines going to the fuel pump has a line coming out of it that goes to vacuum on the block and that could explain all the fuel being dumped into it.

 

[Claw]

I am going to do a full oil replacement tomorrow.
I drained everything from the oil tank and cranked it a few times and got more out. I did not drain out of the crank or change the filter.
I have a filter already ready.
Just thought maybe I had gotten it all since I drained nearly 2 gallons.
How much oil is typically in the crank when all levels are proper?
I believe its only a gallon in total for a complete oil change.
Think theres a chance that I just did not drain enough out?
And, if thats the case, why would the oil tank keep filling up? Would it not still stay at the same level if I have fixed the carb issue?

 

[Claw]

The vacuum lines seem good.
When I pull them, they are dry
When the engine is running, they suck air which they should.

So the fuel pump has 2 lines going to it from the tank. Then 2 lines that feed 2 carbs each. Then there is the 2 vacuum lines that go from the pump to carb #1 and carb #4
Just to be sure

 

[kviper]

Sounds right. You would need to draw vacume to the pumps and see if you can draw fuel in to the vacume line. You are getting a huge volume of fuel in the oil some how. Fuel pump comes to my mind.
If a diaphragm in the fuel pump has a hole in it it can suck fuel straight to the motor

 

[Claw]

I have read about this same thing happening. Turned out to be stuck needles.
When I changed mine, I thought it would fix the problem.
I drained oil from only the oil tank.
Could there have just been a bunch of fuel in the crank and that is what filled my oil return?