Author Topic: Engine locked up on me this morning...help? (Read 5019 times)

Russtang · « **on:** January 24, 2006, 11:46:23 AM »

Well, I went out this morning to warm up the bike. 91 G4 I got a couple of months ago. I turned the choke on and pushed the starter button. I heard the starter crank a couple times, then THUNK.

Pressing the starter again did nothing...well, except for loading the battery and dimming the lights. Engine is locked up.

Anyone ever have this happen to them? The bike has been sitting since Friday.

I'm thinking (hoping) fluid lock. The petcock arrow doesn't point to any of the indicators properly and the bike seems to run with it in any position. Checking it out was on my list this weekend. It was a low priority because of the need for vacuum to allow gas to flow. I would also need a float to stop floating or the float needle valve to stop sealing to flood the bike. It has moved up in priority today.

Here's my plan:

1. Pull the plugs.
2. Give the start button a quick press to see if things turn and gas shoots out. Maybe putting it in gear and trying to roll it would be better/safer?
3. If that fixes it, replace oil, clean/install plugs and work on petcock.
4. If not, come back here and beg for help.

Any advice would be appreciated.

Russ

PitterB4 · « **Reply #1 on:** January 24, 2006, 11:58:43 AM »

There are plenty of stories like this on 400s. Check your oil level and/or smell the oil. If it’s hydrolocked, it’s likely a combination of two things – a bum petcock and bad o-rings in the carbs. Pulling the plugs and hitting the starter is a sure-fire test. Watch out, the stuff LAUNCHES! I’ve got a ~10 ft ceiling in my garage with gas stains on it! I’d do everything you’ve suggested except the bump-start. I would think that would be a good way to bend something.

Oh BTW – for the B4, “working on the petcock” means $74 for a new one.

Russtang · « **Reply #2 on:** January 24, 2006, 12:09:39 PM »

Quote from: "PitterB4"

I’ve got a ~10 ft ceiling in my garage with gas stains on it!

Hehe. Thanks for the quick reply Rob. Sounds like you have previous experience in this department.

Quote from: "PitterB4"

Oh BTW – for the B4, “working on the petcock” means $74 for a new one.

Good lord.

Hopefully I can find one in my "spare bike pile of goodies"

Russ

Red01 · « **Reply #3 on:** January 24, 2006, 07:22:34 PM »

Pretty much what Rob said. You could try turning the motor over (with the the plugs out) with the rear tire and the motor in 4th or higher gear. This would give you the ability to turn the motor over slower than with the starter and push fluid out at a rate that won't spray your ceiling. Once you pushed out the initial bulk, then turn it over with the starter to push out the leftovers.

OTOH, if you're outside and wanna see a model of Old Faithful (maybe even times 4), just do the starter bit.

Russtang · « **Reply #4 on:** January 25, 2006, 11:56:07 AM »

Thanks Paul. Thankfully no old faithful.

Here's an update on what I found out last night:

I pulled the plugs and put a towel across the head. I gave the engine a few cranks. Nothing shot out, but I was able to see a little puddle of gas at the top of piston #3. I guess it must have all drained into the pan overnight. I drained the oil, blew out each cylinder with my air gun, and let it all drain/dry out overnight. This morning I reinstalled the plugs and put new oil in.

The fuel valve has got me stumped though. Hopefully someone can shed some light on it's proper operation. I apologize if this belongs in the bandit 400 forum, but I'm hoping other models share the same valve. I know it'll definitely get more exposure here too.

Here is a crude drawing of my valve:

In testing without pulling a vacuum on the diaphragm, I got no flow with the arrow pointing at both ON and RES. I got plenty of flow with the arrow pointing up...what I have always assumed to be the OFF position.

When I pulled a vacuum on the valve diaphragm, I got plenty of flow with the arrow pointing at any of the three positions.

The manual doesn't describe the valve's operation in any detail. Anyone out there able to shed light on the correct operation of the valve? Is "arrow pointing down" off?

Thanks in advance,
Russ

interfuse · « **Reply #5 on:** January 25, 2006, 12:11:27 PM »

Straight up = prime > full on fuel flow
On = Off > without vacuum

Russtang · « **Reply #6 on:** January 25, 2006, 01:59:03 PM »

Quote from: "interfuse"

Straight up = prime > full on fuel flow
On = Off > without vacuum

OK, thanks interfuse.

So there's no true OFF position? Meaning we are relying on the lack of vacuum (and the diaphragm) to keep fuel from flowing to the carbs? This goes against all my dirtbike experience with fuel petcocks, so forgive my need for clarification.

So does everyone just leave their valves in the ON position (unless you need to switch to reserve of course)?

Russ

PitterB4 · « **Reply #7 on:** January 25, 2006, 02:05:19 PM »

Like IF said, up is "Prime" = free flowing fuel. On Res or On, vacuum is required to draw fuel. The only difference in those two is the length of the straw in the tank from which they draw. Sound like yours might be OK if it's not flowing when set to On with no vac. Mine leaked pretty bad when I would just set the tank on the ground.

Try this - pull the bowl off #3. Does the float seat well or is it loose? I'll bet it's loose which will dump a bunch of fuel in that cylinder when the system is under vac. The cause of the loose float is a worn out o-ring or two. I'd replace 'em all. Make sense?

Russtang · « **Reply #8 on:** January 25, 2006, 02:34:02 PM »

Quote from: "PitterB4"

Like IF said, up is "Prime" = free flowing fuel. On Res or On, vacuum is required to draw fuel. The only difference in those two is the length of the straw in the tank from which they draw. Sound like yours might be OK if it's not flowing when set to On with no vac. Mine leaked pretty bad when I would just set the tank on the ground.

Yep, I had been turning the fuel supply "OFF" by turning the valve to point up. I assumed the valve had ON, REServe, and OFF positions. DOH!

Quote from: "PitterB4"

Try this - pull the bowl off #3. Does the float seat well or is it loose? I'll bet it's loose which will dump a bunch of fuel in that cylinder when the system is under vac. The cause of the loose float is a worn out o-ring or two. I'd replace 'em all. Make sense?

Yep, makes complete sense. Guess I should have mentioned that I knew I needed to look at the number 3 float valve. Been doing that fer too many years on my dirtbikes...only 1/4 the amount of carbs though.

I was just so perplexed at the crazy fuel valve operation (in my mind) that I left that part of the story out.

Speaking of which, anyone know the best place to buy a carb o-ring kit for a 91 G4? Other than the dealer of course.

It's still going to take some behavior training to keep me from moving that fuel valve every time I shut off the bike!

Thanks,
Russ

PitterB4 · « **Reply #9 on:** January 25, 2006, 02:56:27 PM »

You can usually do at least slightly better than the dealer through Bike Bandit (see banner at the bottom of the page).

There is no way to turn the petcock totally off.

Russtang · « **Reply #10 on:** January 25, 2006, 03:06:02 PM »

Cool, thanks Rob

mike · « **Reply #11 on:** January 25, 2006, 04:55:06 PM »

Quote

There is no way to turn the petcock totally off.

Farre · « **Reply #12 on:** January 29, 2006, 12:45:22 PM »

yeah, i had the same 'problem' i was loking all over to find the "OFF" setting, luckily the screw was still in place so i couldn't make the mistake of putting it in Prime. I found out quickly enough when we pulled the tank off the next day (no gas leaking? WTF? :-P)

Russtang · « **Reply #13 on:** January 30, 2006, 11:52:39 AM »

Thanks all. Rode to work this morning. Runs like a champ again!

Russ