Gas in the oil

[acook3323]

Came out to the bike this morning and found oil everywhere with gas in it. It was coming out of the bike like water. Changed the oil completely (drain plug, oil screen, and clutch cover). Now it seems to be happening again. Has anyone had this issue. I tried to start the bike and it wamted to startbut wouldnt ignite..

[Z1R rider]

Float needle in carb not closing, and petcock leaking, not shutting off. Gas overflows carb, runs into cylinder, drips (or runs) past rings, fills crankcase. Pull the sparkplugs before cranking so you don't bend a rod (if) when it hydro locks.

[acook3323]

Originally Posted by Z1R rider

Float needle in carb not closing, and petcock leaking, not shutting off. Gas overflows carb, runs into cylinder, drips (or runs) past rings, fills crankcase. Pull the sparkplugs before cranking so you don't bend a rod (if) when it hydro locks.

Changed the oil and tried to start again and got nothing any ideas?

[Z1R rider]

Make sure the gas in the carbs is at the right level, got spark (plugs not fouled), and some compression in the cylinders and it should light. Really hard to give good advice long distance.

By "tried to start" I'm assuming the starter is rotating the engine.

[ducatiman]

Originally Posted by acook3323

Changed the oil and tried to start again and got nothing any ideas?

You failed to address the primary problem ..specifically the float system (within the carbs)....which will likely continue to overflow and contaminate the oil....also affecting starting and running.......until corrected.

As Z1 stated, the petcock likely at fault too.

[DannoXYZ]

You need to fix cause of this problem, not just cleaning up messy results. Imagine you've got fridge with tilted shelf and you come here asking for advice on cleaning up spilt milk on your floor. You say you wiped it up every time, but whenever you open fridge, more bottles of milk fall out and break on ground. You try and shove milk bottles to back of angled shelf and they still fall out. Fix the problem! Make that shelf flat!

In this case, it's most likely that petcock is not shutting off:

1. Make sure the petcock is in the OFF position
2. Disconnect fuel-hose from bottom of petcock
3. Is there fuel dribbling out of petcock?


Btw, stop trying to start the engine until you fix problem!!! You're gonna hydrolock the engine and send a rod out the side of the case!!! It will be safe to start engine when there's no more gas dripping through engine when at rest. And that can only happen AFTER you fix the leaking petcock!!!

[Ram Jet]

Originally Posted by JacRyann

You need to fix cause of this problem, not just cleaning up messy results. Imagine you've got fridge with tilted shelf and you come here asking for advice on cleaning up spilt milk on your floor. You say you wiped it up every time, but whenever you open fridge, more bottles of milk fall out and break on ground. You try and shove milk bottles to back of angled shelf and they still fall out. Fix the problem! Make that shelf flat!

In this case, it's most likely that petcock is not shutting off:

1. Make sure the petcock is in the OFF position
2. Disconnect fuel-hose from bottom of petcock
3. Is there fuel dribbling out of petcock?


Btw, stop trying to start the engine until you fix problem!!! You're gonna hydrolock the engine and send a rod out the side of the case!!! It will be safe to start engine when there's no more gas dripping through engine when at rest. And that can only happen AFTER you fix the leaking petcock!!!

I'm too lazy right now to look but the 250's carbs don't have a float bowl overflow tube running out of each carb? My Mikuni does.

Bill

[ducatiman]

250 Keihin 30mm....no separate overflow...the vent system does double duty....vent and overflow out the common rail into the attached big brown hose out the backside.

Just dabbled with some BSDT38 38mm Mikunis (from a Ducati twin) just yesterday...vent and overflow systems are in fact separate.

[DannoXYZ]

Also float-bowls dripping will dump at most... 10-15cc into engine? Not gallons of gas.
All that extra gas beyond what is sitting in the floats is coming from somewhere...

[Ram Jet]

Originally Posted by ducatiman

250 Keihin 30mm....no separate overflow...the vent system does double duty....vent and overflow out the common rail into the attached big brown hose out the backside.

Just dabbled with some BSDT38 38mm Mikunis (from a Ducati twin) just yesterday...vent and overflow systems are in fact separate.

I'd like to lose these vacuum carbs and install some Yamaha RD350/400 carbs on my Ninja. Someday.

I thought Duke's ran Dellorto carbs. Yeah, Bill, maybe in 1971.

Bill

[Ram Jet]

Originally Posted by JacRyann

Also float-bowls dripping will dump at most... 10-15cc into engine? Not gallons of gas.
All that extra gas beyond what is sitting in the floats is coming from somewhere...

Crazy thought, forgive me in advance. Is it possible that the fuel outlet on the tank got connected to the vacuum hose on the left carb and you have a leaky petcock. Hey, stranger things have happened.

Bill

[DannoXYZ]

Originally Posted by Ram Jet

Crazy thought, forgive me in advance. Is it possible that the fuel outlet on the tank got connected to the vacuum hose on the left carb and you have a leaky petcock. Hey, stranger things have happened.

Bill

Hey, good idea! Certainly a possibility!!


This case brings back warm-fuzzies for me. Back in '88 when I was going to UCSB, I bought an '86 VF500F for just $400!!! Kid had gotten it for HS graduation and kinda abused it and thought he fried engine and locked-up/welded the rings to the cylinders. Starter just buzzed. Bump-starting it just dragged the rear-tyre without spinning it; yup, seized engine, I'll buy it for parts.

Then I unscrewed the oil-filler cap and WHOoosh!!! A couple gallons of gas+oil flowed out like a waterfall! Yep, petcock failed and leaked an entire gas-tank of fuel into the engine's crankcase and cylinders. So I drained everything, cranked out the gas in the cylinders, refilled with oil and made a $3000 profit in just half a day! Yeehaa!!!!

[acook3323]

Alright, cleaned carbs checked petcock, checked spark, everything is looking good now but still won't start. The first try or 2 it will almost start but not really keep going but after that nothing will even ignite.

[Ram Jet]

Originally Posted by acook3323

Alright, cleaned carbs checked petcock, checked spark, everything is looking good now but still won't start. The first try or 2 it will almost start but not really keep going but after that nothing will even ignite.

Sound like the carbs are flooding. If you pull the plugs are they wet with fuel?

Bill

[Z1R rider]

You have to be sure that the fuel level is right in the carb bowls, and have to be sure the carbs are clean, (I know you already cleaned them) I had mine on and off so many times getting them right, I thought I was going to wear the screws out. These two things are the most common things to keep a bike from running. Don't just take my word for it. Here's a link to a video explaining some symptoms.

http://www.motorcyclistonline.com/vi...&video=x5bbdku

If your 110% sure the carbs are clean (not just the jets, but the passages inside the carbs also), then I'd probably try new spark plugs, (just because it's easy) sometimes they will fire in open air but not under compression. Next I'd do a compression test, just to be sure things are sealing well and nothing is broken after being full of gas. Then I'd adjust the valve clearances.
If you have these 3 things, air/fuel mixture close to right, a spark at close to the right time, and a little compression (180 lbs is good, should run on 80 lbs) it should run.

PS: Ducatiman has a carb cleaning service that is, from what I gather, second to none!

[ducatiman]

^ yup

[acook3323]

Got carbs cleaned for the 4th time.. it will start with starter fluid had them professionally adjusted. Petcock is not faulty flow stops when in the off position. I can feel air pushing out when i remove the plugs so it has asst least some kind of compression

[spent_too_much]

Just a thought. Is there a chance that your fuel tank has a pin-hole leak - or larger? That might explain the fuel on the floor.

[spent_too_much]

Look at it this way. You now have gained knowledge, and have the satisfaction that YOU fixed your MC yourself. I too try to do it all myself, and in the process learn by trial and error.

[acook3323]

Originally Posted by spent_too_much

Just a thought. Is there a chance that your fuel tank has a pin-hole leak - or larger? That might explain the fuel on the floor.

Great thought but no. When the fuel tank is off I have no problems!

[ducatiman]

Originally Posted by acook3323

Got carbs cleaned for the 4th time.. it will start with starter fluid had them professionally adjusted. Petcock is not faulty flow stops when in the off position. I can feel air pushing out when i remove the plugs so it has asst least some kind of compression

you later post..."When the fuel tank is off I have no problems!"

These seem to be contradictory statements. In the interest of helping, I must ask you to clear up a few questions...

*am I led to believe the bike is still spilling fuel, as you stated in your original post? If so...*precisely* where/what is the source of the leakage?
*a 4th cleaning and still requires starting fluid? Does it continue to idle on its own, or stall out? How long does it run?
*the petcock should only flow ONLY in on or res position and ONLY if vacuum is being applied...its flowing in ON or RES without vacuum? If so, it IS faulty.

Also, was the bike running ok prior to your original post regarding suddenly finding the leak and a no start situation? In daily use?

Please clarify the above.

[acook3323]

Originally Posted by ducatiman

you later post..."When the fuel tank is off I have no problems!"

These seem to be contradictory statements. In the interest of helping, I must ask you to clear up a few questions...

*am I led to believe the bike is still spilling fuel, as you stated in your original post? If so...*precisely* where/what is the source of the leakage?
*a 4th cleaning and still requires starting fluid? Does it continue to idle on its own, or stall out? How long does it run?
*the petcock should only flow ONLY in on or res position and ONLY if vacuum is being applied...its flowing in ON or RES without vacuum? If so, it IS faulty.

Also, was the bike running ok prior to your original post regarding suddenly finding the leak and a no start situation? In daily use?

Please clarify the above.

No more spilling fuel, starts uo for a second then dies. The petcock flows as if gravity fed until shut off and this is tge first time its had issues. The bike ran great for a few months until this point

[ducatiman]

Within the thread, some posts misleading...made it seem its fixed.

So the petcock needs repair or replace

Carbs? 4 attempts? Who's doing them?

I'll submit your carbs need a thorough, comprehensive service and setup

I'd immediately discontinue the use of start fluid....its poison to diaphragm rubbers and plastic slides. Destructive and doesn't get to the root of the problem any way.

[DannoXYZ]

Originally Posted by acook3323

Got carbs cleaned for the 4th time.. it will start with starter fluid had them professionally adjusted. Petcock is not faulty flow stops when in the off position.

Well, now we have more info to work with! If petcock flows in ON position without vacuum on diaphragm, then it's definitely bad! Also explains how all fuel dripped into crankcase. Kinda a pain to have to remember to turn off fuel every single time you stop. Get that petcock replaced with one that doesn't flow in the ON position unless there's vacuum applied.

There's still a second problem though? How did you "clean carbs" 4 times?

1. By spraying carb-cleaner down the throats like starter fluid?
2. Did you remove carbs from engine?
3. Did you remove each jet individually and floss them with wire?
4. Which of the following fuel-circuits did you clean and what tools did you use?

Originally Posted by n4mwd

Here are the secret passages in the carbs. They are kindof hard to figure out sometimes and this picture guide will show where they are for cleaning purposes.

Carb Pilot jet Circuit


Carb Main Jet Circuit


Carb Fuel and Overflow Drain


Carb Diaphragm Intake, upper choke and vacuum ports


Carb Choke Circuit

I suspect your carbs aren't really "cleaned".

[acook3323]

Originally Posted by JacRyann

Well, now we have more info to work with! If petcock flows in ON position without vacuum on diaphragm, then it's definitely bad! Also explains how all fuel dripped into crankcase. Kinda a pain to have to remember to turn off fuel every single time you stop. Get that petcock replaced with one that doesn't flow in the ON position unless there's vacuum applied.

There's still a second problem though? How did you "clean carbs" 4 times?

1. By spraying carb-cleaner down the throats like starter fluid?
2. Did you remove carbs from engine?
3. Did you remove each jet individually and floss them with wire?
4. Which of the following fuel-circuits did you clean and what tools did you use?



I suspect your carbs aren't really "cleaned".

For the passages ive always just used carb cleaner amd compressed air. Any suggestions on better tools. Completely removed the carbs amd disassembled and yes flossed all 4 jets

[DannoXYZ]

Good 'ole fashion pipe-cleaners work well for the fuel-passages.

After you try cranking for a while with no start, pull the plugs and take a look. Are they dry or wet?

[ducatiman]

Take a real good look at the tiny transition ports in the venturi...they branch into the pilot circuit...like roots of a tree.

I'll stick with ultrasonic, chemicals and soda blasting....multiple courses as needed.

A home garage setting can't compete with modern, specialized equipment and methods.

[acook3323]

Okay so checked the carb all ports are allowing fluid through them. The only way I can get the bike to start is if I completely remove the left hand spark plug. If I remove the boot only it will not start

[Ram Jet]

Originally Posted by acook3323

Okay so checked the carb all ports are allowing fluid through them. The only way I can get the bike to start is if I completely remove the left hand spark plug. If I remove the boot only it will not start

With the plug removed and the plug inserted into the boot and then grounded to say one of the cam cover bolts, do you see a spark at the plug gap when you tun the engine over with the starter motor?

Bill

[acook3323]

Yes there is a big spark when I ground it

[Ram Jet]

Originally Posted by ducatiman

250 Keihin 30mm....no separate overflow...the vent system does double duty....vent and overflow out the common rail into the attached big brown hose out the backside.

Just dabbled with some BSDT38 38mm Mikunis (from a Ducati twin) just yesterday...vent and overflow systems are in fact separate.

Thank you Gordon. Three months later and after about a billion postings later I'm still learning. Now, off to find out how to adjust the headlight on a pre-gen.

I don't want to hear if you own a Duke or not.

Bill

[ducatiman]

Originally Posted by Ram Jet

Thank you Gordon. Three months later and after about a billion postings later I'm still learning. Now, off to find out how to adjust the headlight on a pre-gen.

I don't want to hear if you own a Duke or not.
Bill

I'll resist the obvious temptation to post numerous pics while endlessly testifying to its off-the-charts fun factor

[Ram Jet]

Originally Posted by ducatiman

I'll resist the obvious temptation to post numerous pics while endlessly testifying to its off-the-charts fun factor

You have good taste my friend. I nearly bought a Ducati in 1975 until I opened the gas cap and saw the gas tank full of rust on the showroom floor. A 1970 or 71' Super Sport would do - back when they had genuine desmo gear drives.

Bill