Engine hydrolocking after took it to the shop

[dafox999]

Team,

my '83 interstate wasn't getting gas to the left bank, and I just didn't want to do the rebuild, sync, etc. so took it to a shop that specialized in vintage bikes. Long story, but five months later and a couple of ridiculous diagnosis, they finally rebuilt the carbs. Before I picked it up they said my fuel pump was leaking. It wasn't before I took it in, but oh well. Another month later they said this rebuilt one (ebay) they put on leaked too, so make sure I turned my gas off when not riding. I figure I can find/fix a leak. I leave the gas on for a few days. No gas anywhere. I hit the starter and it just locks. So, I charge my battery, still the starter tries, but nadda. I pull the plugs to see if it will spin it without compression. 1/2 liter of gas shoots out my left bank. Hydrolocked. It leaks INTO the carbs (cylinders, crankcase, etc.). So, I change my oil and here I am.

My opinion is it's not the footvalve in the fuel pump, otherwise, it would leak into my right bank .. right? So .. either the floats are sinking, or the needle/seats are screwed up .. right? I figure they rebuilt the carbs, screwed up the needle/seat and then assumed it was my (good) fuel pump, and replaced it. Now, if the fuel pump is good, doesn't it have a valve that is supposed to keep fuel from flowing to the carbs? Maybe I've got two problems? I've rebuilt a lot of outboard and car carbs, but never a bike. I've got the shop manual and it looks pretty straight forward. I could take it back to them, but after already paying $1100 and them screwing up brakes and carbs (my front caliper almost caught on fire after 4 miles out of the shop), I think I'll pass.

Any / all input is welcome.

 

[mcgovern61]

Boy oh boy that is a sad story! It is too bad that shops take that much time and then do not fix your bike correctly and then charge almost the value of the bike to fix it!

Leaking carbs and hydrolock. Several things here. First off, close your petcock when the engine is off, these systems will leak if the tank is more than half full. Most likely, the gas in the cylinders is improperly adjusted carb floats and most definately the needles and seat are not closing all the way (very common with this vintage).

It would not surprise me that a shop could rebuild carbs by basically changing out the parts and send it back to you leaking. It is not hard to set the floats correctly and it just takes time and patience to clean the needles and seats although they can be purchased new from Honda.

 

[slabghost]

You got robbed of your riding season and money. I've never heard of hydro locking caused by the fuel pumps. Time for you to go through the carbs yourself. There are some really good threads and tutorials here on how to do it. Welcome to the forum. We could have gotten you on the road for a lot less I think.

 

[joedrum]

sheesh those guys were just compete idiots period im sorry you got so screwed by these people ... they obviously know nothing about oldwings for them to come up with fuel pump as problem ..sheesh past that id never take the bike back to them ... just be glad they didn't destroy the bike along with the big ignorant rip off they did to your funds .....there a simple floe and stop test that sould have been done after the rebuild to comferm no leaks before install back on the bike sheesh ... if you start a thread here and can post pics im sure we can you can beat this 1100dollar screw up big time

 

[skiri251]

My input is more like another question.

GL is my first and only motorcycle with a fuel pump.
I just removed the engine from the frame and re-installed it.
What I noticed is that it took considerable cranking until the gas finally reached the carbs.
It's not gravity fed setup so hard to believe the gas from the gas tank flood the crank case.
If it were my XS750 (infamous for that gasoil issue due to failed vacuum operated petcock), yes absolutely.

Granted my fuel level in the tank was fairly low.
If the gas tank is almost full, does the gravity push the gas into the crank case through fuel pump and leaky carbs?

 

[joedrum]

yes

 

[dan filipi]

Fuel pump has nothing to do with the flooding.

There is no shutoff of any kind in the pump but that fact will not cause the flooding.

Best habit is to turn the fuel petcock off when the engine isn't running.

McGovern nailed this exactly right.

Welcome to the forums.
We'll help every way we can.

 

[AApple]

You could still have all 4 carbs leaking, but only fill the left hand cylinders...IF you park it on the side stand....
I always turn the fuel off before I get parked and shut down, so the fuel level in the bowls will be lower than "normal" when parked. I usually turn the petcock OFF about a block from the house/work.

No matter...still sounds like your carbs may be out of whack, but it's worth checking with the petcock OFF, and see if it fills the cylinders...and put it up ion the center stand, if at all possible. :good:


Welcome to the CGW Forums, too, btw!! :clapping: :clapping:

 

[joedrum]

yah me too joel ..then I promply run out of gas as soon as I get to the road ...sheesh its hard to keep up :doh:

 

[dafox999]

Hmmm ... just read some more posts. I think the pump is fine ... one (or many) carb needle/seat/float is out of whack .. and it's not a huge deal as everyone seems to turn the gas off each time. When I do that, I do not have this issue. I'm 99% certain it was on the centerstand when hydro'd.

 

[dan filipi]

Your MPG will tell you a lot here about the carbs' condition and floats.
If they're leaking past while riding then your MPG will go down.
"Normal" (acceptable) MPG for the 1100 is at least 40.

 

[mcgovern61]

skiri251 » Mon Sep 23, 2013 11:10 am[/url]":12gb1jv4]
What I noticed is that it took considerable cranking until the gas finally reached the carbs. It's not gravity fed setup so hard to believe the gas from the gas tank flood the crank case.
If it were my XS750 (infamous for that gasoil issue due to failed vacuum operated petcock), yes absolutely.

Normally I would agree except that I have hydrolocked my engines several times before I fixed my carbs. If the tank is full, and the petcock is left open, there is just enough pressure if the needle is not seated and closed to leak by. If the leak starts, it begins a siphon and slowly pulls gas out of the tank. I have also had my carbs leak into the engine when my petcock was closed as a result of the same issue......gas leaking past the needle and seat in my left side carbs (#2 and #4). It is frustrating at first and the down side is if you do not know they are leaking like that and have not hydrolocked the engine, you are not aware that there is gas in the oil washing and wiping out your bearings!

 

[dafox999]

Thanks again, guys.

So, went out to see how hard to pull carbs. and noticed my vacuum advance hose lying on top of the engine. Not connected to vacuum port. Jeez. it was clearly cut off and is now too short. Will get a little hose and re-connect. This won't fix the leaking, but clearly my timing has not been advancing, and I've had a vacuum leak. It idles GREAT in spite of the leak, but I have noticed an occasional buck/pop at highway speeds and a flat spot in mid range (maybe due to timing), but will affect MPG and power.

I'm 99% sure the bike was on the center stand.

Hoping to simply pull the carb assembly and just drop the bowls and check needles/seats/float levels soon. I don't care to tear them down any further than I have to.

The carbs are lower than the mid-point in the gas tank, so I'd guess when tank is full, head pressure will push gas through, but when it is low, this doesn't happen.

 

[dan filipi]

but when it is low, this doesn't happen.

It still can with pressure building in the tank from heat and normal fuel evaporation increasing pressure in the tank.

 

[dafox999]

So, I've been working on other issues and making good headway. Not certain I want to pull all four carbs and try to re-set the floats, but might.

On (maybe) another topic, I've noticed an occasional "pop" or knock or kick-back. Very minor, but sounds a bit like pre-ignition. I looked in my shop manual and it seems I don't get to set the timing?

Just once in awhile I get this low level pop or kick, so once ahHard to believe the float setting (or needle/seat sticking) is the issue.

Again .. open to all thoughts.

 

[Steve83]

If your advancer plate is sticking, the timing could be too far advanced, causing the kickback. You can check the timing, but it's pretty much impossible to adjust it with the engine in the frame - unless you remove the swingarm...

Anyway, if you pull the small hose from the #3 carb that goes to the vacuum advance and suck on it, you should hear the advance plate move. It takes very little vacuum to move it. It should also NOT have a constant flow when suction is applied. If there is flow, the diaphragm in the vacuum advance is leaking.

If you do this test with the engine running, the RPM's should change slightly when vacuum is applied.

Another selling point for the C5 ignition - no moving parts for timing advance. OK, Paul, where's my commission? :smilie_happy:

 

[mcgovern61]

Steve83 » Sat Sep 28, 2013 11:47 pm[/url]":1ssnfno9]
Another selling point for the C5 ignition - no moving parts for timing advance. OK, Paul, where's my commission? :smilie_happy:

Steve, you get three Atta-boys for that! :hihihi:

 

[zman]

dafox999 » Sat Sep 28, 2013 8:32 pm[/url]":xrfrbuyn]
So, I've been working on other issues and making good headway. Not certain I want to pull all four carbs and try to re-set the floats, but might.

On (maybe) another topic, I've noticed an occasional "pop" or knock or kick-back. Very minor, but sounds a bit like pre-ignition. I looked in my shop manual and it seems I don't get to set the timing?

Just once in awhile I get this low level pop or kick, so once ahHard to believe the float setting (or needle/seat sticking) is the issue.

Again .. open to all thoughts.

If you do take them back off check the float needles carefully. If they havent been replaced you can buy just the float needles for 7-8 bucks each. The trouble is ,with old needles even if the conical tip looks and act`s good the tiny fragile spring in the needle can be weak/stick causing a little or allot more gas to seep past after it should be fully closed and under tank pressurization can even cause your cylinders to flood.
The trouble is a static test may show them not leaking but under stresses of operation, differing pressures they will.

 

[slabghost]

These old carb racks are a bit finicky and the ignition was never really precise. Getting the carbs as close to "right" as you can get them and the spark as good as you can will minimize the "pop" occasions.

 

[dafox999]

Thanks guys,

Yeah .. I did suck on the advance tube and there is no flow, and the revs kick up slightly, so I think the vacuum advance is working. No idea if the mechanical advance is. Whats' a C5 ignition? Something I could replace mine with?

From what I'm reading, it sounds like the setup is a bit persnickety. Maybe I'll just put up with the occasional "pop". Not sure I want to pull the carbs and dink with them.