• Can't post after logging to the forum for the first time... Try Again - If you can't post in the forum, sign out of both the membership site and the forum and log in again. Make sure your COG membership is active and your browser allow cookies. If you still can't post, contact the COG IT guy at IT@Concours.org.
  • IF YOU GET 404 ERROR: This may be due to using a link in a post from prior to the web migration. Content was brought over from the old forum as is, but the links may be in error. If the link contains "cog-online.org" it is an old link and will not work.

Hyrdrolock?

littletontall6249

Member
Member
Hydrolock link gives message "The requested page could not be found."

I am a new owner of 1999 Concourse 18,000 miles. I was a few minutes into a ride when I experienced loss of power that felt like low on gas. I switched to reserve but didn't make much difference. It would not idle without throttle and sounded like not all cylinders were firing. Nursed it home to find gas leaking onto the ground. Opened air box to see gas leaking into it. It will not turn over now when trying to restart it (only tried once).

Is this hydrolock and what should I be doing about it?

Andy

I
 
Remove the spark plugs, eliminate sources of spark, cover the top of the motor with a rag, crank the motor - you might find gas spurting from one spark plug hole. To see if you bent a rod insert a dowel in each spark plug bore and and turn the motor until each cylinder reaches the top of its travel. Compare heights. The carburetors will need to be taken apart and cleaned. Overflow tubes can be installed. Steve in Sunny Florida is the best for cleaning and rebuilding the carbs - he has instructive videos that make removal and installation of the carb racks as easy as it can be.
It's very possible that there is no damage to the connecting rods but the carb problem needs to be fixed. Overflow tubes will assure peace of mind in the future.
 
Thanks, greenie. Looks like its time to get intimate with the bike! I was told by the seller that the previous owner had the carbs rebuilt. So maybe the gas tank has crud in it causing the trouble despite an inline filter.
 
Some time back I acquired a 87 with 18k.

After doing carb rebuild, tubes, inline filter, rebuilt fuel petcock and a tank clean and resealed with the Caswell process, I still had float sticking issues on too many an occasion. I pulled carbs replaced all float needles again with maw kaw needles (not needles from the kits) and polished the needle seats with toothpaste and q-tip chucked in a drill. This helped immensely but still float needles would stick though much less so after all that. Mostly #4. But was random needles also.

Determined finally it was alcohol in fuel causing a very fine crystalline deposit on carb jets and rubber needle tips. To fix that I now use Lucas fuel injector cleaner, Marvel Mystery oil, and a TW3 type 2 stroke oil in a combination added to each tank. The mix goes in tank at each fill up. Maybe a ounce or so. I also lube the tank latch mechanism at same time with a few drops.

I have not had a incident since instituting this procedure more than 2 years ago now. Before that I had gotten so good, if tapping the flooding carb would not stop overflow, I could pull bowl w/o removing carbs. Glad that PIA procedure and skill set is no longer needed.

It should have not been an issue after all that truly. With the additive solution it has never been again. Hope this helps
 
MERCER's comments and procedures are great as far as maintaining the carbs, and I agree 100%, but there's only one real prevention for hydro-lock and that's installing the float bowl drain tubes, to drain off the extra fuel. Greenie is right, if you don't want to or can't do the carb mod/drain tube install yourself, then by all means send then to Steve In Sunny Florida, it's worth the money. Also, drain and flush your fuel tank at least once a year.. The "cheeks" at the rear where your knees sit contain about 1/3 gallon of gasoline that has all the water and crud that settles there and there is no way to drain it out since it is below the level of the petcock. You have to pull the tank, drain it out by pulling the fuel gauge float, and the petcock and turning it over and blowing air through it, etc., and flush it clean with new fuel.

An awful lot of hydrolock threads start with the statement "the previous owner had the carbs rebuilt". By whom, and for what reason??? That generally means there was a problem, so someone took them apart and put them back together......problem fixed??? Mebbe so...mebbe no. Best of luck to you.
 
When you pull the spark plugs it should be evident which cylinder(s) got flooded by the gas soaked plugs. When you do the piston height check you don't need to crank the motor to top dead center, 2 Pistons should be at the same height and the other 2 should be at the same height regardless of their actual heights in the stroke cycle. You are checking to see if they match each other. Hope it checks out ok, I bought my bike hydro locked and the previous owner told me it had a problem with the starter not turning over the engine. I found that it did not bend a crank, thanks from this same info I got from this forum awhile back.

I agree that it sounds like something held the float valve open. There might of been something electrical that killed power to certain spark plug(s) even momentarily that would foul the plug(s) that they do not usually recover from but it wouldn't flood the airbox with gas, imo. Fouled plugs are hard to get back to 100% again, with that low of mileage they should have little or no wear.

Check the oil in your crankcase as if the cylinder(s) got flooded, gas will seep past the rings into the crankcase. Open the oil fill cap and carefully insert a rod into the crank acting like a dipstick and smell the oil for gas.

Once you get the flooding sorted out if you are near due for an oil change I would change it and the filter out. FYI, there are two oil drain screws in the bottom of the oil pan.

You have a 22 year old bike and there are things with a bike of this age needs attention to, especially one that hasn't been ridden much and maintence may not been kept up with because of the low mileage vs age perception.
Steve's carb service goes beyond what a mc repair shop or a shade tree mechanic would perform and he has done so many of these carbs. Adds overflow tubes to carb bowls. He adjusts the float bowl shutoff heights (that could be your problem, improper float height shutoff, should shut gas off near the bowl to carb mating surface to slightly above, if the actual float needle valve didn't have crud in there to stop it from closing.)
There is an inherent problem that these carbs had from the factory when new, that is a slight stumble/hesitation in the lower rpms that Steve's rebuild gets rid of. He also de racks the carbs from each other and replaces the rubber bits in between the carbs. If the piston height check comes out good, the bike is in good shape, and you intend on keeping the bike you might want to send the carbs to Steve, a little pricey but you will forget about the money spent for the ride-ability received when you just have to install them and the reliability of them further down the road.

A lot of writing but good luck and keep us posted.
 
Step 1; Find out if you bent any rods.


Step 2; Report back.
Step 3; If no bent rods, "then" send the carbs to Steve.

Ride safe, Ted
 
Step 1; Find out if you bent any rods.
Step 2; Report back.
Step 3; If no bent rods, then send the carbs to Steve.

Ride safe, Ted

Ride safe, Ted
Ted put it short and sweet.
Thanks Ted, my long version had a sentence in there that sort of stated the same thing but might of been overloooked by Andy and anyone else that uses this post for reference in the future.
"If the piston height check comes out good, the bike is in good shape, and you intend on keeping the bike you might want to send the carbs to Steve"
 
Quote from Nosmos in #6 above:

"The "cheeks" at the rear where your knees sit contain about 1/3 gallon of gasoline that has all the water and crud that settles there and there is no way to drain it out since it is below the level of the petcock."

This is a very real concern for C10 owners! Especially as our bikes become oh so older.

The way I dealt with this design flaw was as follows:

When treating my tank with a Caswell coating system. I did not drain the tank of surplus epoxy sealer. Instead I positioned tank so all excess epoxy sealer would fill the voids in tank below petcock with a slope towards tank center. I now have a no void tank with no undrainable collection points in these cheeks. This save the sending unit side of tank in general. That drainage requires acute left hand lean angles!

Living with moisture rusting tanks from inside in a subtropical environ like we have in Louisiana is always a problem. I always epoxy line all my metal vehicle tanks. The ones I plan to keep a long time anyway. I have used Caswell after having other systems fail. Even with a superior product like Caswell, I can not emphasize proper preparation and etching the metal prior to internal coating/sealer treatment enough. I have never ever had a Caswell failure in the decades I have used this system.

Hope this ditty helps those who will ride a C10 till there is no ride left.
 
Let me add that if gas was leaking into the airbox when the engine was off, you also have a bad petcock. The stock vacuum petcock will not flow gas in on or reserve without the engine running. Prime bypasses the need for vacuum. I am going to guess that it is shutting off or you would have drained the whole tank onto the floor.
 
Thanks for the update on the link. It opens for me now. Lots of helpful advice in this piece with regards to fuel issues! This article and everyone's advice in this forum has helped tremendously toward relieving the anxiety of how to attack my bike's old age problems.
Low mileage 1999 Concourse
 
Let me add that if gas was leaking into the airbox when the engine was off, you also have a bad petcock. The stock vacuum petcock will not flow gas in on or reserve without the engine running. Prime bypasses the need for vacuum. I am going to guess that it is shutting off or you would have drained the whole tank onto the floor.
Also possible than you had the petcock in the "Prime" {forward} position?
In "Prime", and check valve is bypassed, and the gas flows freely.

Ride safe, Ted
 
Looking for some advice.
I'm in the process of sending carbs to Steve and looking into sealing the gas tank. It is a California bike with three orifices on the rear. What is the best method of keeping these from being closed off during the sealing process? And what is the best method of sealing the petcock, filler hole, and fuel level sensor opening during the sealing process?

Is it best to replace vacuum petcock with a manual one?
Update so far: I watched leaking gas into airbox with petcock in the "on" position with bike not running.
Removed spark plugs and pistons are at same levels using Steve's method seen on YouTube.
Used starter with coils removed and gas sprayed out of #1 cylinder.
 
Great news on the piston height check results!
That may have been residual gas in the line from the petcock.
When you pulled the tank off with the petcock on run did/has gas seep out of the petcock? Like others have said your float height or float valve interference in not closing for some reason was the cause of the overfilling carbs and subsequent gas in the air box.
I have no experience in sealing the tank. Do you see much surface rust in the tank through the gas cap? The other area to look for rust is to examine the tank on the outer bottom seams especially in the lowest lying area of the tank for bubbling paint. Do not break any bubbling paint as that may cause a leak in the tank.
 
I've never sealed a tank so can't help there but stick with the vac operated petcock (new) when replacing . The carbs will have overflows when they come back so you're covered there .
 
I would recommend the PUR - 15 system for treating your tank. You will need to set aside a day for prep and treatment and ensure nothing to interrupt during certain stages of the process. Some steps you can take as much time as necessary and the longer duration the better. I have tried using vinegar which is safe and almost idiot proof but its not quite good enough for really rusted tanks but good pre treatment to remove some of the easy rust and slug. I have tried electrolysis with mixed results...again probably a good pre-treatment for hard to reach and narrow or small contours of the tank. I finally settled on the PUR -15 read instructions several times and made sure everything I needed was at hand and waited till wife was running errands. Now tank is in great shape. One thing the previous two processes revealed was a very small pin hole that was able to
solder shut and then the PUR 15 made sure it was sealed from inside. Good luck
 
It sounds like you had rust in your tank, and the rust caused the petcock/carbs to leak?

Many have removed the California Emissions components. Relatively EZ to do.

I also used POR-15 (Paint Over Rust).
It worked well for me. But, you "must" follow the directions carefully and do a good prep.

To seal the holes during treatment;
* I made aluminum block off plates with paper gaskets.
** I used a rubber plug to seal the fill hole.
The vent lines are all above the gas cap seal and do not require sealing during treatment.

When you get the carbs back from Steve, they will have overflow tubes in them.
The overflow tubes {stand pipe tubes} will prevent the possibility of hydro lock.

Most think it best to keep the vacuum petcock (as it cannot be left "on" accidentally).
(with the overflow tubes) you could use either without the concerns of hydro lock.
BUT!! (If you left the manual valve on and again got trash under a carb seat) Gas could leak out onto the ground "while in storage".

Ride safe, Ted
 
Last edited:
For hydro lock you need to have 2 failures. Both a bad petcock and a leaking float valve. If you go to a manual petcock and do not turn it to off as soon as you stop the engine you have created 1 of the conditions that can lead to hydro lock. By having Steve put in the overflow tubes you are adding a safety for the duel failure by having a place to drain before filling your cylinder with fuel.

Your loss of power was due to a too rich condition caused by the leaking float valve raising the fuel level in the float bowl and spilling into the intact track. Some times it will only be bad at idle because the engine use that extra fuel at higher RPM's. The overflow tube can keep you running at idle just dripping fuel out the tubes at idle, so you have to be aware if you ever smell fuel at a stop.

No help with the tank coating.
 
Regarding manual petcocks:

I installed a Pingel manual valve years ago to get rid of the repeated problems with the vacuum valve. (Others have reported 20 years good service with the OEM valve and never having problems.) However, as stated above, manual valves should ONLY be used with overflow tubes. Without the overflows, then yes, you actually increase the risk of hydrolock if you forget to turn it off. You also risk the embarassment/danger of the engine quitting in about 20 seconds if you forget to turn it back ON when leaving the restaurant parking lot. Ask me how I know. It's also problematic of you have another bike, like my Wee-Strom 650, that's fuel injected and has no petcock. You have to remember which bike you are riding. So I make it a "muscle-memory" habit of reaching down to shut off the valve when I get off, even if there's no valve there.
 
Seller of my bike said he rebuilt the petcock and gave me the "Fuel Tap Repair kit" packaging with the old parts. Could it have been assembled wrong?
Gas tank emptied this morning and removed the fuel filler cap, petcock, and gas level sensor. Inside surfaces of the tank looks pretty good. Only light rust here and there - mostly at metal joints. The drained gas had small particles in it. The petcock filter had the gap as mentioned in another post.
Carbs are removed and ready to ship to Steve this week when I can get to the post office.
 
I have had of mixed results with the petcock rebuild. 1 lasted years another only weeks. It is recommended to use Kawasaki parts and to stretch the spring a little bit. There is a small alignment nub on 1 of the parts. I don't remember which one. If the screen is damaged, I would get a new one.
 
If its very light rust you might use the vinegar method outlined in Revzilla. Instead of sealing the last step is putting some kerosene in the tank and making sure it covers the inside (slosh) it around. The kerosene helps prevent flash rusting until you fill the tank with gas and the kerosene mixes well with the gas. Guy that used this method says he lives where weather doesnt permit riding for a few months so he removes his tank and treats it with kerosene and sloshes it around once a week and swears no rust.
 
I used to have mixed results with tap rebuilding across bike types until I read somewhere about trueing surfaces on a flat surface with fine paper. I also polish o-ring seat with toothpaste and q-tip. I have used a thin paper gasket below rubber seal sometimes if if needed at selector. I also have tossed petcocks as non rebuildable due to casting defects. Never over tighten screws as this messes with your true of surfaces would say also. As well check that vacuum ball check functions in the outer diaphragm cover. If stuck or sluggish that is a often missed problem. I remove the stock in tank fuel filter also as most warp at seat and are useless shortly after new.

So having said all above. I still have a 5/16ths inline fuel tap and filter downwind of vacuum tap with a red handle in plain site.
I have trained myself to turn that red handle before turning on or removing ignition key. Why the dual redundancy? Why all this above?


With carb tubes installed in float bowls you can come back to ride and find all fuel dumped to ground save for reserve from vacuum tap failure and sticking float. If left on prime all fuel is gone! Worse might be to answer a fire alarm! Any petcock as from new or float valve can fail, it is not just poor rebuilds that can fail this way.

Hope this helps someone. If you ride old iron? Your skill set needs to be older/bolder than and as smart as Hedy Lamarr would guess.


What is life without a history lesson thrown in!
 
WOW!

MERCER: Thanks for the link to Hedy Lamarr's history....I had no idea! I guess that's where they came up with expression "not just another pretty face". I wonder how many other people did cool stuff we know nothing about.

And your comments about faulty petcocks draining all the fuel through the overflow tubes is why I installed the manual Pingel. Off is OFF, no springs, vacuum diaphragms, etc. Unless of course, I leave it ON. :eek:
 
Last edited:
I have the best of both. If I forget the red manual tap. The vacuum petcock is there to cover for my senility. Redundancy is only as good as my luck and my feeble mind however.
 
Top