Author Topic: I Hydrolocked my connie  (Read 7212 times)

Offline Jet86

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I Hydrolocked my connie
« on: May 12, 2011, 03:41:46 am »
Well it happened, how unlucky can i be, i hydrolocked my bike and the forum went down the same day, i guess i had a little luck on my side as no major damage was done.

i was 20 miles from home and before i left i switched the petcock to prime and drove off, every so often i will ride on reserve or prime for 20 miles or so then switch back to on when i get to where I'm going, well i forgot to switch it back this time.

came out of the supper market and hit the start button and it turned over a few times then  "CLICK" & Lock, it wasn't really loud but i knew immediately what it was and let off the switch quick, good thing i carry a small toolbox in the bag with basic tools, i just needed some shade, pushed the fat cow 2 blocks and found some, a 99 cent store was close by so i went and bought a towel to cover the Cylinder, pulled tank & plugs - unplugged the stick coils and moved the wires back so i wouldn't blow myself sky-hi, laid the towel over the plug holes and hit the starter button and she immediately turned over blowing out what seemed to be a pint of gas from the #1 Cylinder, and yeah even with that towel she spit in my face after partially blowing off the towel but i was happy she turned over, i cranked about 10sec then removed the towel and cranked another 10sec, let her rest 15min then gave 1 more good 15-20 second crank til i could not see anymore gas coming out, stuck her back together and drained the carb bowls and primed for 3sec then switched to on and she fired up, drove home and she ran just like always. i bet i wont ride with it on prime anymore.
the petcock is working like it should 6 months new from murph's.

TWO QUESTIONS

1. Can the bike hydrolock if I'm riding it?
2. Do i now have gas in my oil? i only rode home 20 miles and haven't started her since.


1986 California Connie 87k and counting

Offline Electroken

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Re: I Hydrolocked my connie
« Reply #1 on: May 12, 2011, 03:47:51 am »
I'm glad you got off easy.
1. It will not hydrolock while running unless you ride into a lake.
2. If it sat for more than a few minutes with fuel in a cylinder, you have fuel in your oil.

Offline Jet86

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Re: I Hydrolocked my connie
« Reply #2 on: May 12, 2011, 04:37:20 am »
Thanks i better change the oil then, i was in the store for at least 15min or more.


1986 California Connie 87k and counting

Offline Steve in Sunny Fla

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Re: I Hydrolocked my connie
« Reply #3 on: May 12, 2011, 05:36:39 am »
 you'll need to address why it hydro'ed, or it'll do it again. I'd suggest to get the petcock replaced, tank cleaned, carbs cleaned, and get some overflow tubes installed - just in case. with hydrolock and the connie, it's not an issue of "if" it's an issue of "when" - and the results range from contaminated oil to a bent connecting rod - HTH, Steve

Offline Jet86

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Re: I Hydrolocked my connie
« Reply #4 on: May 12, 2011, 06:06:52 am »
The petcock is about 6 months new from murph's and working fine, thats the first thing i checked when i pulled the tank, it's a Tank + carb issue = stuck float/needle, I wont have any money for at least 2 months' so after the oil change she will sit for awhile.

btw would you happen to have a clean used tank for sale? i think i read you said you had one for sale but not sure if you sold it or not.


1986 California Connie 87k and counting

Offline mlf73

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Re: I Hydrolocked my connie
« Reply #5 on: May 12, 2011, 06:36:19 am »
The petcock is fine right...since it was on prime...it did what it was supposed to do?  The failure was with a carb needle or float and of course, no overflow tubes? 
02 Conc- Corbin seat, Cee Baileys shield, MCL fork brace, 4 pot calipers w/zrxmopar's adapters, 310mm rotors, SS brake lines, 1.1 Sonic springs, C14 rear shock, TCro's stick coils, SiSF's economy jet kit, front tip-over bars w/hwy pegs, KB bar risers, fender extender, block off plates, HVMP bar end weights, grip heaters, Murphs fuse block, 55W HID upgrade, relo'd coolant bottle & helmet locks

Offline Steve in Sunny Fla

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Re: I Hydrolocked my connie
« Reply #6 on: May 12, 2011, 07:04:24 am »
The petcock is fine right...since it was on prime...it did what it was supposed to do?  The failure was with a carb needle or float and of course, no overflow tubes?

  Nice catch! He did say that in the OP, I just missed it  :-[ .

   I'd like to add that it has been said that hydrolocks are the result of 2 failures, the petcock and a float needle. I'm modifying my position on that, after having done literally dozens and dozens of carbs at this point. I think that the floats apply such light seat pressure to the needles that the head pressure from a reasonably full tank of fuel could overcome a needle with a soft spring and cause it to seep, resulting in hydrolock. HTH, Steve

  bTW, I do have a very nice tank - email or PM if interested - steve
« Last Edit: May 12, 2011, 07:06:15 am by Steve in Sunny Fla »

Offline Jet86

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Re: I Hydrolocked my connie
« Reply #7 on: May 12, 2011, 07:49:46 am »
And i keep my tank full most of the time, and it was my fault for leaving it on prime when i new full well the carbs has been needing attention for a long time now, i think they needed rebuilt since the day i bought it 3 years ago but it has only been the this last 3 months they getting really bad, once the bike is good and warm and i shut it off for 15min then try to start it it backfires out the exhaust, and while im cranking i can hear whats seems to be a slight knocking in the head, i think that knocking is mini hydrolocks.

PM on it's way


1986 California Connie 87k and counting

Offline dbethel

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Re: I Hydrolocked my connie
« Reply #8 on: May 12, 2011, 09:49:20 am »
You were lucky, but check piston height to make sure.

D. 

Offline norcalbarney

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Re: I Hydrolocked my connie
« Reply #9 on: May 12, 2011, 09:55:08 am »
I did the same thing.  I left the petcock on prime after pulling the tank, and my float valve failed in #4.  There was gas under the carbs, but I was foolish enough to keep trying to start it, tho.  I had a HUGE backfire, and now the #4 piston is about 3/8 lower than #1, and it won't crank past that point, so I've got a bent rod.  Now it's my parts bike!

I have sent a set of carb bowls to Steve in S Florida for the overflow tube treatment.  I think it's $70 well spent, especially for newbies like me.  Or you could install them yourself.  There *used to be* a post around here.... : )
« Last Edit: May 12, 2011, 10:28:25 am by norcalbarney »

Offline mdr

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Re: I Hydrolocked my connie
« Reply #10 on: May 12, 2011, 11:01:12 am »
I think that the floats apply such light seat pressure to the needles that the head pressure from a reasonably full tank of fuel could overcome a needle with a soft spring and cause it to seep, resulting in hydrolock.

Lets run the numbers...

I'm not near a bike, but I'll guess around 12" from top of the tank to the float needle.  I'll show the formulas so you can calc it yourself within 0.1mm if you want :)

pressure head = (specific weight) * height

specific weight ~= 0.026 lb/in^3 (wikipedia and others)

pressure head = 0.026lb/in^3 * 12in = 0.312 lb/in^2 or ~0.3PSI

In a thread on the old boards it was said the seat is about 2mm in diameter, 1mm or 0.04" radius (about 39.4 mils).  So,

area = pi * (radius)^2 = 3.14 * (0.04)^2 = 0.005 sq in

force = pressure * area = 0.3 * 0.005 = 0.0015lbs or 0.02 ounces.

Unless I've goofed the math, I don't think so.
Mark in Austin
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http://www.randols.net/Connie/index.html

Offline norcalbarney

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Re: I Hydrolocked my connie
« Reply #11 on: May 12, 2011, 11:32:37 am »
 

   I'd like to add that it has been said that hydrolocks are the result of 2 failures, the petcock and a float needle.

I'd like to add two more reasons that Connies seem to hydrolock, that Steve may have overlooked with his years of experience : First is riders leaving the petcock on Prime, bypassing the vacuum on the petcock, allowing fuel to press on the needle valves.  Sure, everyone should keep the petcock on ON, not prime, but some riders (like me) might not know that.

A second, worse, less forgivable mistake ignorant riders (like me!) make is to try to start the bike after the needle valves failed, and there's already gas in the cylinder.  They see the pool of gas, and try to start it anyway.  It's hard to believe that pressing that little red button on my sturdy bike could kill it, but it can.  In my case, there was a huge backfire, and the bike was hydrolocked.  Now I've got a carcus.

Certainly Steve knows his Sh*t, and you should listen to him.  I'm just adding this for people that don't know nuthin, like me.  And get Steve's overflow tubes installed!  : )

Offline Roadhound

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Re: I Hydrolocked my connie
« Reply #12 on: May 12, 2011, 02:40:09 pm »
Just always remember, when you approach your bike, if you see gas on the ground or if you smell gas, check it out before you hit the starter button. You and your Concours can live a long and happy life with or without overflow tubes as long as you use your head.
Don Ricks
Atlanta, Ga.

"Ride or Ride not, there is no drive."

Offline Daytona_Mike

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Re: I Hydrolocked my connie
« Reply #13 on: May 12, 2011, 03:52:24 pm »
Just always remember, when you approach your bike, if you see gas on the ground or if you smell gas, check it out before you hit the starter button. You and your Concours can live a long and happy life with or without overflow tubes as long as you use your head.
That will work only if you smell gas. Many times you may not. It only takes a few seconds of leaving a manual petcock in the ON position or an automatic on Prime (or it failed in Prime) to have a Hydo-lock Occur. I never smelled gas when I almost hydro locked and I was in a garage. I even had a sign that said to tap the starter to make sure the engine is free but I kept forgetting to do that.
You may take your chances and possibly   live a long happy life without over flow tubes but you will not be safe from Hydrolock at all and  thinking you  do not need over flow tubes is a mistake that could cost you your engine. Why take the chance? Get overflow tubes installed ASAP.
If you still have fuel in the tank, you are not lost yet
Most motorcycle problems are caused by the nut that connects the handlebars to the saddle

Offline Roadhound

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Re: I Hydrolocked my connie
« Reply #14 on: May 12, 2011, 07:01:28 pm »
That will work only if you smell gas. Many times you may not. It only takes a few seconds of leaving a manual petcock in the ON position or an automatic on Prime (or it failed in Prime) to have a Hydo-lock Occur. I never smelled gas when I almost hydro locked and I was in a garage. I even had a sign that said to tap the starter to make sure the engine is free but I kept forgetting to do that.
You may take your chances and possibly   live a long happy life without over flow tubes but you will not be safe from Hydrolock at all and  thinking you  do not need over flow tubes is a mistake that could cost you your engine. Why take the chance? Get overflow tubes installed ASAP.

Well it's worked for me for over 500,000 miles. If I turn my petcock to prime my hand never leaves the petcock until I turn it back to on or reserve. Leaving the petcock on prime is the most dangerous thing you can do, and totally avoidable.
Don Ricks
Atlanta, Ga.

"Ride or Ride not, there is no drive."