Fuel in oil, but float valves working

[pancho]

Your coming right along SC Valkman,, looks like you should be back on the road soon....  then we will see....  Your bike is pretty clean underneath,, did you get it like that ot did you clean it up??

[Ricky-D]

Brake fluid

***

[Tropic traveler]

It has been mentioned before that a stuck open needle valve cannot flow enough gas to cause the oil level to rise.
Yes it can.
One leaky needle/seat valve greatly over filled the crankcase with fuel on my '97 several years ago.
Went out to start the '97 for a days ride & I had the dreaded hydro-lock. Did not break anything. Saddled up the R3 & went for the days ride. Upon my return the Valk cranked right up with a sputter & was waaay over full of gasoline smelling oil. Second carb on left bank needle/seat held open by rust & trash from the gas tank. Cleaned all 6 carbs & tank then replaced offending needle/seat & petcock.
That was 38,000 miles ago at 78,000 miles.
Obviously enough fuel passed through the petcock, needle/seat assembly then piston rings, to both over fill the crankcase & hydro lock the engine.
The fuel that was causing the hydrolock in the morning had leaked down past the rings by the evening which allowed me to get it started when I returned.
As evidenced by the 38,000 miles I have put on the bike since the incident, the fuel leaking past the rings did not cause damage to the pistons, rings, or cylinder walls.  
Find the cause & fix it, change the oil & ride!  

[Rio Wil]

Aha.....learn something new everyday.....

The first photo shows the D shaped hole/slot mentioned by SC_Valkman as the crankcase overflow port.  It appears the function of that hole is to serve as a weep hole for any brake (clutch) fluid that might leak from the clutch slave cylinder (not a desirable thing ya understand).  The other thing it might do is alert you to any degradation in the oil seal where the clutch lifter rod enters the clutch cavity to actuate the clutch stack. If the oil seal is worn/shrunken (overly full crankcase?) it would allow oil to seep around the clutch cylinder body and out the weep hole just as the hydraulic fluid would do......  The slave clutch housing is just a slip fit into the clutch cover housing and no seal is used at this interface which would allow for the seepage.  

So, you could have been alerted to the overly full crankcase by seepage past the lift rod/oil seal and past the clutch housing out the weep hole......or it could have been a seepage from the clutch hydraulic cylinder, but you indicated the clutch master cylinder is not low on fluid.

[Rio Wil]

Rio, this guy is just learning his bike and has been working under a few misconceptions.

 Does RIO stand for the backseater of a Phantom?

Chuckle......by this time, he is no  longer a novice on this engine......he has had the top half of the beast scattered from here to Timbuktu??     I admire his tenacity!!

Nah.....Rio is just short for Rio Vista, CA........but that would have been a real experience!

[pancho]

Hmmm, it seems that if the seal is damaged, SOME oil will tend to come out weather or not it is overfull.......  interesting.......

[pancho]

I think you're mistaken.

That is a relief for the slave to let any brake fluid pass that may be leaking from the piston.

***

???????  While it would certainly do that Ricky, it is probably there for air pressure equalization as the slave piston moves in and out.

[SC_Valkman]

Love the pictures and comments of where that hole in the crankcase leads. 

Well the fuel test of the float valves showed that one or more on the right side leak, so I took them apart and testing individually.  As Tropic Traveler mentioned, this leaked alot of gas in a short time.  Whoever mentioned not trusting your blowing into the carb fuel port and inverting it to check the seals was absolutely correct, so glad I did the real fuel test.  Here's some pictures of my test fixtures -

-- Carb Assembly Test --


-- Individual Carb Test --


#1 carb float valve held, so now it's off to #3 and #5.  Since I already have the test fixture, I'll probably test the left bank (2,4 & 6).  As a note, I'm relocating the fuel resevoir on top of the fixture and inserting a small fuel cutoff valve (lawnmover) so I get good gravity flow and don't have to waste quite as much gas.  Well, back to finding the culprit in this problem.  I appreciate all the inputs and support.


 

[salty1]

Impressive and well thought. 

[pancho]

I think you're mistaken.

That is a relief for the slave to let any brake fluid pass that may be leaking from the piston.

***

???????  While it would certainly do that Ricky, it is probably there for air pressure equalization as the slave piston moves in and out.

..   HA  ..  That will teach me to open my big mouth!!!  When this happens can it usually be fixed with just the piston seal/cup, or is the cylinder generally scored which would require replacing the assembly??  I had the rear apart for routine inspection of my "wing pressout" final drive, splines, pcup etc... after 3500 miles, and saw this.  I cleaned it up and reassembled, but I need to order parts now and be back here real soon.

 

[SC_Valkman]

Update to those that have been tracking this thread, my 1997 Valkyrie is back on the road again.  Here are some pics showing the final tests before completion:

Step 1 - Verified petcock valve worked correctly and fuel flowed only when vacuum applied


Step 2 - Verified that none of the float valves were sticking by checking if fuel stopped flowing when bowls were full.  Performed 3 - 4 times by draining bowls, then letting fill until flow stopped.


Step 3 - Verified petcock and carb assembly did not leak when vacuum applied.


Step 4 - Installed tank and carbs back on to bike, and then cranked it up but did not run smooth so broke out carb synch quad vacuum gauge set.  I aligned all carbs relative to #3 cylinder as per manual and where throttle cables attach.  All 6 cylinders set at 9 inches Hg vacuum and she runs really smooth.


Step 5 - Installed all remaining parts (seat, windshield, saddlebags, etc.), and then gave it drive test.  I cannot remember it ever running this smooth plus it had great torque at low RPMs.  I'm still waiting on the Pilot Screw Wrench and precision tachometer, but the 2 1/2 turns out for the initial set up seems to be fine.  I'll ride it around town for now, but no long trips until I get the pilot screws adjusted.  I appreciate everyone's inputs and hopefully this thread will help anyone else that runs into the same problem.  Take care and see you out on the roads.

[salty1]

Happy Trails S  C Valkman! Don't you just love it when a plan comes together? 

[whitestroke]

So the verdict was that fuel was leaking past the float valve and down the intake past the valves and piston rings into the crank?

[pancho]

I don't go for that........... unless he is missing some rings as he never had a hydrolock episode.

[SC_Valkman]

I did have the starter symptom for hydrolock 6 months ago, but for some reason I did not list it in the beginning of this thread.  I thought the starter gear was stuck in the flywheel, so I got the bike rolling and then engaged 2nd gear.  I do not remember removing the spark plugs, so it must have worked the gas out.  The bike started and then I drove it.  I took the carb assembly off and opened up each bowl to check for a stuck float valve, but none found so put back on the bike.  I changed the oil, and then took the bike out for test drive.  The oil leak followed that incident, so I knew the problem had not gone away. 

By the way, I share your opinion that gas should not be able to leak past the rings if they are not worn out and a hydrolock symptom should be your clue of a leaking float valve.  Last week, I checked the compression and all 6 cyclinders were showing around 160 psi so the rings are in great shape and any gas leaks should result in hydrolock.  After a trip down to the gas station (10 miles), the oil showed a litttle high probably from the left over gas mixed in it and heat expansion so I changed it and the filter.  I was busy yesterday, so no drive tests yet.  I hope this problem is solved, because I'm starting to get real tired of taking those carbs apart.

I appreciate everyone's suggestions or comments.

[Daniel Meyer]

Gas flows past piston rings fairly easily...it's not fast, but it does flow past 'em.

[pancho]

Well I for one hope the problem is in the past Valkman.... whatever the cause!!  I imagine you are about ready to do some riding instead of working on it.

[SC_Valkman]

Went on about a 30 mile ride today, so checked the oil level and it was holding steady.  Hopefully problem solved, so now I'm just waiting on the pilot screw wrench and digital tachometer to dial in the idle mixture.  I'll probably re-test the carb synchronization after setting the pilot screws, which is about 20-30 minute process.  The pilot screws are tough to reach and you have to do the adjustment with a warmed up engine and it is running, so hopefully the tool helps minimize burns and the cursing.  A few more short trips (30-50 miles), and then I may venture out on a much longer one (200-300 miles).  My lower back gets tired on those longer trips, so I may invest in a new seat with the lower back support.  I use a throttle lock as my cruise control, so another investment would be switch it out for an electronic one like the Goldwings.   I'll search the other threads for any issues or preferences for the seat selection or the cruise control.  I enjoyed learning about the bike's carburetion system, but it's also nice to get back on the road again.

[al v]

Be sure to remove your alternator cover when you do the carb sync so as not to overheat it. The heat from the bike not moving can possibly wrinkle the chrome. I say "possibly" because it seems to be one of the hotly debated causes of the cover wrinkling/peeling. Can't hurt to take it off either way. (Wish I had taken mine off when I did the last carb sync.)

[SC_Valkman]

It was already wrinkled before starting the project, so must have been sitting traffic too long.  I did have it off along with the side panels during all testing, so I could have full access and see if there were any leaks.  I wonder if it's worth buying a new one if they are so prone to wrinkle?

[Rio Wil]

I don't go for that........... unless he is missing some rings as he never had a hydrolock episode.

Think about it.....the compression rings fit in grooves with a few thou clearance on the sides of the rings as well as a gap at the end of the ring of maybe .010 or more, the oil ring presents no obstacle to any fuel flow.....so no real problem to slowly fill the crankcase.

[pancho]

Maybe..... what gets me is the first couple of sentences in this post.  The petcock did not leak, the crankcase overfilled over night.. just does not add up....

Even if the petcock and carbs were leaking enough to over fill the crankcase over night, you would expect a cylinder to be full of gas and cause a secondary problem.... several unlucky ones have experienced it.

I just hope Valkmans problems are behind him and he can be riding instead of working on his bike.....

[Rio Wil]

Its a pretty unique sequence of events that has to occur to produce the hydrolock any way...

Needs fuel flow thru the petcock when supposedly shut off (generally)
Needs a carb float to stick open
Need the offending cylinder to not be any where in the firing/exhaust stroke when cranked
Needs enough fuel captured in the cylinder (ie, not leaked into the crankcase)


So you can have different degrees of any/all the above.....I would not be surprised if the conditions are not partially met quite often and we simply get away with it....our only indications might be.....hummm, exhaust has a heavy fuel smell today on startup..... and the fuel boils out of the crankcase while we happily twist the throttle.